Revision 45:c42166b2878c, committed 2016-02-15

Comitter:

mjr

Date:

Mon Feb 15 20:30:32 2016 +0000

Parent:

44:b5ac89b9cd5d

Child:

47:df7a88cd249c

Commit message:

More work in progress on CCD speedups;

Changed in this revision

--- a/AltAnalogIn/AltAnalogIn.h	Sun Feb 07 03:07:11 2016 +0000
+++ b/AltAnalogIn/AltAnalogIn.h	Mon Feb 15 20:30:32 2016 +0000
@@ -23,65 +23,64 @@
  */
 #include "mbed.h"
 #include "pinmap.h"
+#include "SimpleDMA.h"
+
+// KL25Z definitions
+#if defined TARGET_KLXX
+
+// Maximum ADC clock for KL25Z in 12-bit mode - 18 MHz per the data sheet
+#define MAX_FADC_12BIT      18000000
+
+#define CHANNELS_A_SHIFT     5          // bit position in ADC channel number of A/B mux
+#define ADC_CFG1_ADLSMP      0x10       // long sample time mode
+#define ADC_SC1_AIEN         0x40       // interrupt enable
+#define ADC_SC2_ADLSTS(mode) (mode)     // long sample time select - bits 1:0 of CFG2
+#define ADC_SC2_DMAEN        0x04       // DMA enable
+#define ADC_SC3_CONTINUOUS   0x08       // continuous conversion mode
+
+#else
+    #error "This target is not currently supported"
+#endif
 
 #if !defined TARGET_LPC1768 && !defined TARGET_KLXX && !defined TARGET_LPC408X && !defined TARGET_LPC11UXX && !defined TARGET_K20D5M
     #error "Target not supported"
 #endif
 
- /** A class similar to AnalogIn, only faster, for LPC1768, LPC408X and KLxx
- *
- * AnalogIn does a single conversion when you read a value (actually several conversions and it takes the median of that).
- * This library runns the ADC conversion automatically in the background.
- * When read is called, it immediatly returns the last sampled value.
- *
- * LPC1768 / LPC4088
- * Using more ADC pins in continuous mode will decrease the conversion rate (LPC1768:200kHz/LPC4088:400kHz).
- * If you need to sample one pin very fast and sometimes also need to do AD conversions on another pin,
- * you can disable the continuous conversion on that ADC channel and still read its value.
+ /** A class similar to AnalogIn, but much faster.  This class is optimized 
+ * for taking a string of readings from a single input.
  *
- * KLXX
- * Multiple Fast instances can be declared of which only ONE can be continuous (all others must be non-continuous).
- *
- * When continuous conversion is disabled, a read will block until the conversion is complete
- * (much like the regular AnalogIn library does).
- * Each ADC channel can be enabled/disabled separately.
- *
- * IMPORTANT : It does not play nicely with regular AnalogIn objects, so either use this library or AnalogIn, not both at the same time!!
- *
- * Example for the KLxx processors:
- * @code
- * // Print messages when the AnalogIn is greater than 50%
- *
- * #include "mbed.h"
+ * This is a heavily modified version of the popular FastAnalogIn class.
+ * Like FastAnalogIn, this class uses the continuous conversion mode to
+ * achieve faster read times.  It adds interrupt callbacks on each
+ * conversion, and DMA transfer of the input data to memory (or to another
+ * peripheral) using the SimpleDMA class.  DMA makes a huge difference -
+ * it speeds up the sampling time by about 3x and gets us fairly close to
+ * the speeds claimed by the manufacturer.  Reading through the MCU code
+ * seems to add at least a few microseconds per sample, which is significant
+ * when trying to get close to the theoretical speed limits for the ADC
+ * hardware, which are around 1.5us.
  *
- * AltAnalogIn temperature(PTC2); //Fast continuous sampling on PTC2
- * AltAnalogIn speed(PTB3, 0);    //Fast non-continuous sampling on PTB3
+ * This class can be used with or without DMA.  By default, you take samples
+ * directly.  Call start() to initiate sampling, and call one of the
+ * read routines (read() or read_u16()) to wait for the sample to complete
+ * and fetch the value.  In this mode, samples are taken individually.
+ * The start() and read routines are separated so that the caller can
+ * perform other work, if desired, while the ADC hardware takes the sample.
  *
- * int main() {
- *     while(1) {
- *         if(temperature > 0.5) {
- *             printf("Too hot! (%f) at speed %f", temperature.read(), speed.read());
- *         }
- *     }
- * }
- * @endcode
- * Example for the LPC1768 processor:
- * @code
- * // Print messages when the AnalogIn is greater than 50%
+ * To use with DMA, set up a SimpleDMA object, and call initDMA() to tie
+ * it to the analog input.  Call startDMA() to initiate a transfer.  We'll
+ * start reading the analog input in continuous mode; each time a sample
+ * completes, it will trigger a DMA transfer to the destination.  startDMA()
+ * returns immediately, so the caller can continue with other tasks while
+ * the samples are taken.
  *
- * #include "mbed.h"
- *
- * AltAnalogIn temperature(p20);
- *
- * int main() {
- *     while(1) {
- *         if(temperature > 0.5) {
- *             printf("Too hot! (%f)", temperature.read());
- *         }
- *     }
- * }
- * @endcode
-*/
+ * IMPORTANT!  This class does not play nicely with regular AnalogIn objects,
+ * nor with the original FastAnalogIn, because all of these classes set global
+ * configuration registers in the ADC hardware at setup time and then will 
+ * assume that no one else is messing with them.  Each library requires
+ * exclusive access to and control over the hardware, so they can't be mixed
+ * in the same program.
+ */
 class AltAnalogIn {
 
 public:
@@ -90,12 +89,70 @@
      * @param pin AnalogIn pin to connect to
      * @param enabled Enable the ADC channel (default = true)
      */
-    AltAnalogIn( PinName pin, bool enabled = true );
+    AltAnalogIn(PinName pin, bool continuous = false);
     
     ~AltAnalogIn( void )
     {
+#if 0//$$$
+        if (intInstance == this)
+            intInstance = 0;
+#endif
     }
     
+    // Initialize DMA.  This connects the analog in port to the
+    // given DMA object.
+    //
+    // DMA transfers from the analog in port often use continuous
+    // conversion mode.  Note, however, that we don't automatically
+    // assume this - single sample mode is the default, which means
+    // that you must manually start each sample.  If you want to use
+    // continuous mode, you need to set that separately (via the 
+    // constructor).
+    void initDMA(SimpleDMA *dma);
+    
+    // Start a DMA transfer.  'nele' is the number of elements (not
+    // bytes) in the buffer.
+    template<typename T> void startDMA(T *buf, int nele, bool autoInc) 
+    {
+        // set the DMA destination buffer
+        dma->destination(buf, autoInc);
+        
+        // start the DMA transfer
+        dma->start(nele * sizeof(T));
+    }
+            
+#if 0 // $$$
+    // set up an interrupt callback and enable interrupt mode
+    template<typename T> void attach(T *object, void (T::*member)(void))
+    {
+        // attach the callback
+        _callback.attach(object, member);
+        
+        // set our internal interrupt handler
+        NVIC_SetVector(ADC0_IRQn, (uint32_t)&_aiIRQ);
+        NVIC_EnableIRQ(ADC0_IRQn);
+        
+        // enable interrupt mode
+        enableInterruptMode();
+    }
+#endif
+
+    // turn on interrupt mode
+    void enableInterruptMode()
+    {
+        // set interrupt mode
+        sc1 |= ADC_SC1_AIEN;        
+    }
+
+#if 0 // $$$    
+    // interrupt handler
+    static void _aiIRQ()
+    {
+        if (intInstance != 0)
+            intInstance->_callback.call();
+    }
+#endif
+    
     /** Start a sample.  This sets the ADC multiplexer to read from
     * this input and activates the sampler.
     */
@@ -115,11 +172,37 @@
                 ADC0->CFG2 &= ~ADC_CFG2_MUXSEL_MASK;
         }
         
-        // select our ADC channel in the control register - this initiates sampling
-        // on the channel
-        ADC0->SC1[0] = startMask;
+        // update the SC2 and SC3 bits only if we're changing inputs
+        static uint32_t lastid = 0;
+        if (id != lastid) 
+        {
+            // set our ADC0 SC2 and SC3 configuration bits
+            ADC0->SC2 = sc2;
+            ADC0->SC3 = sc3;
+        
+            // we're the active one now
+            lastid = id;
+            
+            // handle any interrupts through this object
+//$$$            intInstance = this;
+        }
+        
+        // set our SC1 bits - this initiates the sample
+        ADC0->SC1[0] = sc1;
     }
  
+    // stop sampling
+    void stop()
+    {
+        // set the channel bits to binary 11111 to disable sampling
+        ADC0->SC1[0] = 0x1F;
+    }
+    
+    // wait for the current sample to complete
+    inline void wait()
+    {
+        while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) == 0);
+    }
 
     
     /** Returns the raw value
@@ -129,7 +212,7 @@
     inline uint16_t read_u16()
     {
         // wait for the hardware to signal that the sample is completed
-        while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) == 0);
+        wait();
     
         // return the result register value
         return (uint16_t)ADC0->R[0] << 4;  // convert 12-bit to 16-bit, padding with zeroes
@@ -151,9 +234,17 @@
 
     
 private:
-    char ADCnumber;         // ADC number of our input pin
-    char ADCmux;            // multiplexer for our input pin (0=A, 1=B)
-    uint32_t startMask;
+    uint32_t id;                // unique ID
+    SimpleDMA *dma;             // DMA controller, if used
+    FunctionPointer _callback;  // interrupt callback
+    char ADCnumber;             // ADC number of our input pin
+    char ADCmux;                // multiplexer for our input pin (0=A, 1=B)
+    uint32_t sc1;               // SC1 register settings for this input
+    uint32_t sc2;               // SC2 register settings for this input
+    uint32_t sc3;               // SC3 register settings for this input
+    
+    // interrupt handler instance
+    //$$$static AltAnalogIn *intInstance;
 };
 
 #endif

--- a/AltAnalogIn/AltAnalogIn_KL25Z.cpp	Sun Feb 07 03:07:11 2016 +0000
+++ b/AltAnalogIn/AltAnalogIn_KL25Z.cpp	Mon Feb 15 20:30:32 2016 +0000
@@ -3,17 +3,7 @@
 #include "AltAnalogIn.h"
 #include "clk_freqs.h"
 
-// Maximum ADC clock for KL25Z in 12-bit mode.  The data sheet says this is
-// limited to 18MHz, but we seem to get good results at higher rates.  The
-// data sheet is actually slightly vague on this because it's only in the
-// table for the 16-bit ADC, even though the ADC we're using is a 12-bit ADC,
-// which seems to have slightly different properties.  So there's room to
-// think the data sheet omits the data for the 12-bit ADC.
-#define MAX_FADC_12BIT      25000000
-
-#define CHANNELS_A_SHIFT     5          // bit position in ADC channel number of A/B mux
-#define ADC_CFG1_ADLSMP      0x10       // long sample time mode
-#define ADC_SC2_ADLSTS(mode) (mode)     // long sample time select - bits 1:0 of CFG2
+//$$$AltAnalogIn *AltAnalogIn::intInstance = 0;
 
 #ifdef TARGET_K20D50M
 static const PinMap PinMap_ADC[] = {
@@ -31,8 +21,15 @@
 };
 #endif
 
-AltAnalogIn::AltAnalogIn(PinName pin, bool enabled)
+AltAnalogIn::AltAnalogIn(PinName pin, bool continuous)
 {
+    // set our unique ID
+    static uint32_t nextID = 1;
+    id = nextID++;
+    
+    // presume no DMA 
+    dma = 0;
+    
     // do nothing if explicitly not connected
     if (pin == NC)
         return;
@@ -57,38 +54,72 @@
     // run the ADC at up to 18 MHz per the KL25Z data sheet.  (16-bit mode
     // is limited to 12 MHz.)
     int clkdiv = 0;
-    uint32_t ourfreq = bus_frequency();
-    for ( ; ourfreq > MAX_FADC_12BIT ; ourfreq /= 2, clkdiv += 1) ;
+    uint32_t adcfreq = bus_frequency();
+    for ( ; adcfreq > MAX_FADC_12BIT ; adcfreq /= 2, clkdiv += 1) ;
     
-    // Set the "high speed" configuration only if we're right at the bus speed
-    // limit.  This bit is somewhat confusingly named, in that it actually
-    // *slows down* the conversions.  "High speed" means that the *other*
-    // options are set right at the limits of the ADC, so this option adds
-    // a few extra cycle delays to every conversion to compensate for living
-    // on the edge.
-    uint32_t adhsc_bit = (ourfreq == MAX_FADC_12BIT ? ADC_CFG2_ADHSC_MASK : 0);
+    // The "high speed configuration" bit is required if the ADC clock 
+    // frequency is above a certain threshold.  The actual threshold is 
+    // poorly documented: the reference manual only says that it's required
+    // when running the ADC at "high speed" but doesn't define how high
+    // "high" is.  The only numerical figure I can find is in the Freescale
+    // ADC sample time calculator tool (a Windows program downloadable from
+    // the Freescale site), which has a little notation on the checkbox for
+    // the ADHSC bit that says to use it when the ADC clock is 8 MHz or
+    // higher.
+    //
+    // Note that this bit is somewhat confusingly named.  It doesn't mean
+    // "make the ADC go faster".  It actually means just the opposite.
+    // What it really means is that the external clock is running so fast 
+    // that the ADC has to pad out its sample time slightly to compensate,
+    // by adding a couple of extra clock cycles to each sampling interval.
+    const uint32_t ADHSC_SPEED_LIMIT = 8000000;
+    uint32_t adhsc_bit = (adcfreq >= ADHSC_SPEED_LIMIT ? ADC_CFG2_ADHSC_MASK : 0);
     
-    printf("ADCnumber=%d, cfg2_muxsel=%d, bus freq=%ld, clkdiv=%d\r\n", ADCnumber, ADCmux, bus_frequency(), clkdiv);
+    // $$$
+    printf("ADCnumber=%d, cfg2_muxsel=%d, bus freq=%ld, clkdiv=%d, adc freq=%d, high speed config=%s\r\n", 
+        ADCnumber, ADCmux, bus_frequency(), clkdiv, adcfreq, adhsc_bit ? "Y" : "N");//$$$
 
-    // set up the ADC control registers 
-
+    // map the GPIO pin in the system multiplexer to the ADC
+    pinmap_pinout(pin, PinMap_ADC);
+    
+    // set up the ADC control registers - these are common to all users of this class
+    
     ADC0->CFG1 = ADC_CFG1_ADIV(clkdiv)  // Clock Divide Select (as calculated above)
+               //| ADC_CFG1_ADLSMP        // Long sample time
                | ADC_CFG1_MODE(1)       // Sample precision = 12-bit
                | ADC_CFG1_ADICLK(0);    // Input Clock = bus clock
 
     ADC0->CFG2 = adhsc_bit              // High-Speed Configuration, if needed
-               | ADC_CFG2_ADLSTS(3);    // Long sample time mode 3 -> 6 ADCK cycles total
+               //| ADC_CFG2_ADLSTS(0);    // Long sample time mode 0 -> 24 ADCK cycles total
+               //| ADC_CFG2_ADLSTS(1);    // Long sample time mode 1 -> 16 ADCK cycles total
+               //| ADC_CFG2_ADLSTS(2);    // Long sample time mode 2 -> 10 ADCK cycles total
+               | ADC_CFG2_ADLSTS(3);    // Long sample time mode 2 -> 6 ADCK cycles total
                
-    ADC0->SC2 = ADC_SC2_REFSEL(0);      // Default Voltage Reference
-    
-    ADC0->SC3 = 0;                      // Calibration mode off, single sample, averaging disabled
+    // Figure our SC1 register bits
+    sc1 = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT));
 
-    // map the GPIO pin in the system multiplexer to the ADC
-    pinmap_pinout(pin, PinMap_ADC);
-    
-    // figure our 'start' mask - this is the value we write to the SC1A register
-    // to initiate a new sample
-    startMask = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT));
+    // figure our SC2 register bits
+    sc2 = ADC_SC2_REFSEL(0);            // Default Voltage Reference
+
+    // Set our SC3 bits.  The defaults (0 bits) are calibration mode off,
+    // single sample, averaging disabled.
+    sc3 = (continuous ? ADC_SC3_CONTINUOUS : 0);    // enable continuous mode if desired
 }
 
+void AltAnalogIn::initDMA(SimpleDMA *dma)
+{
+    // remember the DMA interface object
+    this->dma = dma;
+    
+    // set to read from the ADC result register
+    dma->source(&ADC0->R[0], false, 16);
+    
+    // set to trigger on the ADC
+    dma->trigger(Trigger_ADC0);
+
+    // enable DMA in our SC2 bits
+    sc2 |= ADC_SC2_DMAEN;
+}
+
+
 #endif //defined TARGET_KLXX

--- a/SimpleDMA.lib	Sun Feb 07 03:07:11 2016 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1 +0,0 @@
-http://mbed.org/users/Sissors/code/SimpleDMA/#876f3b55e6f5

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SimpleDMA/SimpleDMA.h	Mon Feb 15 20:30:32 2016 +0000
@@ -0,0 +1,210 @@
+#ifndef SIMPLEDMA_H
+#define SIMPLEDMA_H
+
+#ifdef RTOS_H
+#include "rtos.h"
+#endif
+
+#include "mbed.h"
+#include "SimpleDMA_KL25.h"
+#include "SimpleDMA_KL46.h"
+#include "SimpleDMA_LPC1768.h"
+
+
+/**
+* SimpleDMA, DMA made simple! (Okay that was bad)
+*
+* A class to easily make basic DMA operations happen. Not all features
+* of the DMA peripherals are used, but the main ones are: From and to memory
+* and peripherals, either continiously or triggered
+*/
+class SimpleDMA {
+public:
+/**
+* Constructor
+*
+* @param channel - optional parameter which channel should be used, default is automatic channel selection
+*/
+SimpleDMA(int channel = -1);
+
+/**
+* Set the source of the DMA transfer
+*
+* Autoincrement increments the pointer after each transfer. If the source
+* is an array this should be true, if it is a peripheral or a single memory
+* location it should be false.
+*
+* The source can be any pointer to any memory location. Automatically
+* the wordsize is calculated depending on the type, if required you can
+* also override this.
+*
+* @param pointer - pointer to the memory location
+* @param autoinc - should the pointer be incremented by the DMA module
+* @param size - wordsize in bits (optional, generally can be omitted)
+* @return - 0 on success
+*/
+template<typename Type>
+void source(Type* pointer, bool autoinc, int size = sizeof(Type) * 8, int mod = 0) {
+    _source = (uint32_t)pointer;
+    source_inc = autoinc;
+    source_size = size;
+    source_mod = mod;
+}
+
+/**
+* Set the destination of the DMA transfer
+*
+* Autoincrement increments the pointer after each transfer. If the source
+* is an array this should be true, if it is a peripheral or a single memory
+* location it should be false.
+*
+* The destination can be any pointer to any memory location. Automatically
+* the wordsize is calculated depending on the type, if required you can
+* also override this.
+*
+* @param pointer - pointer to the memory location
+* @param autoinc - should the pointer be incremented by the DMA module
+* @param size - wordsize in bits (optional, generally can be omitted)
+* @return - 0 on success
+*/
+template<typename Type>
+void destination(Type* pointer, bool autoinc, int size = sizeof(Type) * 8, int mod = 0) {
+    _destination = (uint32_t)pointer;
+    destination_inc = autoinc;
+    destination_size = size;
+    destination_mod = mod;
+}
+
+/**
+* Set cycle-steal mode.  In cycle-steal mode, we do one DMA transfer per
+* trigger.  In continuous mode, we do the entire transfer on a single trigger.
+*/
+void setCycleSteal(bool f) { cycle_steal = f; }
+
+/**
+* Set the trigger for the DMA operation
+*
+* In SimpleDMA_[yourdevice].h you can find the names of the different triggers.
+* Trigger_ALWAYS is defined for all devices, it will simply move the data
+* as fast as possible. Used for memory-memory transfers. If nothing else is set
+* that will be used by default.
+*
+* @param trig - trigger to use
+* @param return - 0 on success
+*/
+void trigger(SimpleDMA_Trigger trig) {
+    _trigger = trig;
+}
+
+/**
+* Set the DMA channel
+*
+* Generally you will not need to call this function, the constructor does so for you
+*
+* @param chan - DMA channel to use, -1 = variable channel (highest priority channel which is available)
+*/
+void channel(int chan);
+
+/**
+* Start the transfer
+*
+* @param length - number of BYTES to be moved by the DMA
+*/
+int start(uint32_t length);
+
+/**
+* Start a new transfer with the same parameters as last time
+*/
+int restart(uint32_t length);
+
+/**
+* Is the DMA channel busy
+*
+* @param channel - channel to check, -1 = current channel
+* @return - true if it is busy
+*/
+bool isBusy( int channel = -1 );
+
+/**
+* Number of bytes remaining in running transfer.  This reads the controller
+* register with the remaining byte count, which the hardware updates each
+* time it completes a destination transfer.
+*/
+uint32_t remaining(int channel = -1);
+
+/**
+* Attach an interrupt upon completion of DMA transfer or error
+*
+* @param function - function to call upon completion (may be a member function)
+*/
+void attach(void (*function)(void)) {
+    _callback.attach(function);
+    }
+    
+template<typename T>
+    void attach(T *object, void (T::*member)(void)) {
+        _callback.attach(object, member);
+    }
+
+#ifdef RTOS_H
+/**
+* Start a DMA transfer similar to start, however block current Thread
+* until the transfer is finished
+*
+* When using this function only the current Thread is halted.
+* The Thread is moved to Waiting state: other Threads will continue
+* to run normally. 
+*
+* This function is only available if you included rtos.h before 
+* including SimpleDMA.h.
+*
+* @param length - number of BYTES to be moved by the DMA
+*/
+void wait(int length) {
+    id = Thread::gettid();
+    this->attach(this, &SimpleDMA::waitCallback);
+    this->start(length);
+    Thread::signal_wait(0x1);
+}
+#endif
+
+protected:
+int _channel;
+SimpleDMA_Trigger _trigger;
+uint32_t _source;
+uint32_t _destination;
+bool source_inc;
+bool destination_inc;
+uint8_t source_size;
+uint8_t destination_size;
+uint32_t source_mod;
+uint32_t destination_mod;
+bool cycle_steal;
+
+bool auto_channel;
+
+//IRQ handlers
+FunctionPointer _callback;
+void irq_handler(void);
+
+static SimpleDMA *irq_owner[DMA_CHANNELS];
+
+static void irq_handler0( void ); 
+
+#if DMA_IRQS > 1
+static void irq_handler1( void );
+static void irq_handler2( void );
+static void irq_handler3( void );
+#endif
+
+//Keep searching until we find a non-busy channel, start with lowest channel number
+int getFreeChannel(void);
+
+#ifdef RTOS_H
+osThreadId id;
+void waitCallback(void) {
+    osSignalSet(id, 0x1);    
+}
+#endif
+};
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SimpleDMA/SimpleDMA_KL25.h	Mon Feb 15 20:30:32 2016 +0000
@@ -0,0 +1,45 @@
+#if defined TARGET_KL25Z
+
+#define DMA_CHANNELS        4
+#define DMA_IRQS            4
+
+enum SimpleDMA_Trigger {
+    Trigger_ALWAYS = 60,
+    Trigger_UART0_RX = 2,
+    Trigger_UART0_TX,
+    Trigger_UART1_RX,
+    Trigger_UART1_TX,
+    Trigger_UART2_RX,
+    Trigger_UART2_TX,
+    Trigger_SPI0_RX = 16,
+    Trigger_SPI0_TX,
+    Trigger_SPI1_RX,
+    Trigger_SPI1_TX,
+    Trigger_I2C0 = 22,
+    Trigger_I2C1,
+    Trigger_TPM0_C0,
+    Trigger_TPM0_C1,
+    Trigger_TPM0_C2,
+    Trigger_TPM0_C3,
+    Trigger_TPM0_C4,
+    Trigger_TPM0_C5,
+    Trigger_TPM1_C0 = 32,
+    Trigger_TPM1_C1,
+    Trigger_TPM2_C0,
+    Trigger_TPM2_C1,
+    Trigger_ADC0 = 40,
+    Trigger_CMP0 = 42,
+    Trigger_DAC0 = 45,
+    Trigger_PORTA = 49,
+    Trigger_PORTD = 52,
+    Trigger_TPM0 = 54,
+    Trigger_TPM1,
+    Trigger_TPM2,
+    Trigger_TSI,
+    Trigger_ALWAYS0 = 60,
+    Trigger_ALWAYS1,
+    Trigger_ALWAYS2,
+    Trigger_ALWAYS3,
+};    
+
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SimpleDMA/SimpleDMA_KL25_46.cpp	Mon Feb 15 20:30:32 2016 +0000
@@ -0,0 +1,149 @@
+#if defined TARGET_KL25Z || defined TARGET_KL46Z
+#include "SimpleDMA.h"
+
+
+
+SimpleDMA *SimpleDMA::irq_owner[4] = {NULL};
+
+SimpleDMA::SimpleDMA(int channel) {
+    this->channel(channel);
+       
+    //Enable DMA
+    SIM->SCGC6 |= 1<<1;     //Enable clock to DMA mux
+    SIM->SCGC7 |= 1<<8;     //Enable clock to DMA
+    
+    trigger(Trigger_ALWAYS);
+   
+    NVIC_SetVector(DMA0_IRQn, (uint32_t)&irq_handler0);
+    NVIC_SetVector(DMA1_IRQn, (uint32_t)&irq_handler1);
+    NVIC_SetVector(DMA2_IRQn, (uint32_t)&irq_handler2);
+    NVIC_SetVector(DMA3_IRQn, (uint32_t)&irq_handler3);
+    NVIC_EnableIRQ(DMA0_IRQn);
+    NVIC_EnableIRQ(DMA1_IRQn);
+    NVIC_EnableIRQ(DMA2_IRQn);
+    NVIC_EnableIRQ(DMA3_IRQn);
+    
+    // presume cycle-steal mode
+    cycle_steal = true;
+}
+
+// Figure the circular buffer MOD bit pattern (SMOD or DMOD)
+// for a given circular buffer size.  The buffer size is
+// required to be a power of 2 from 16 to 256K.
+static uint32_t modsize_to_modbits(uint32_t siz)
+{
+    // The bit pattern is such that 2^(bits+3), so we basically
+    // need to take the base-2 log of the size.  Zero has the
+    // special meaning that the circular buffer is disabled.
+    uint32_t bits = 0;
+    for (bits = 0 ; siz >= 16 ; siz >>= 1, ++bits) ;
+    
+    // return the result, which can't be over binary 1111
+    return bits & 0xF;
+}
+
+int SimpleDMA::start(uint32_t length) {  
+    if (auto_channel)
+        _channel = getFreeChannel();
+    else
+        while(isBusy());
+    
+    if (length > DMA_DSR_BCR_BCR_MASK)
+        return -1;
+
+    irq_owner[_channel] = this;
+    
+    DMA0->DMA[_channel].SAR = _source;
+    DMA0->DMA[_channel].DAR = _destination;
+    DMA0->DMA[_channel].DSR_BCR = length;
+    DMAMUX0->CHCFG[_channel] = _trigger;
+    
+    uint32_t config = 
+        DMA_DCR_EINT_MASK 
+        | DMA_DCR_ERQ_MASK 
+        | (cycle_steal ? DMA_DCR_CS_MASK : 0)
+        | (source_inc << DMA_DCR_SINC_SHIFT) 
+        | (modsize_to_modbits(source_mod) << DMA_DCR_SMOD_SHIFT)
+        | (destination_inc << DMA_DCR_DINC_SHIFT)
+        | (modsize_to_modbits(destination_mod) << DMA_DCR_DMOD_SHIFT);
+    switch (source_size) {
+        case 8:
+            config |= 1 << DMA_DCR_SSIZE_SHIFT;
+            break;
+        case 16:
+            config |= 2 << DMA_DCR_SSIZE_SHIFT; 
+            break;
+    }
+    switch (destination_size) {
+        case 8:
+            config |= 1 << DMA_DCR_DSIZE_SHIFT;
+            break;
+        case 16:
+            config |= 2 << DMA_DCR_DSIZE_SHIFT; 
+            break;
+    }
+    
+    DMA0->DMA[_channel].DCR = config;      
+           
+    //Start
+    DMAMUX0->CHCFG[_channel] |= 1<<7;
+    
+    return 0;
+}
+
+int SimpleDMA::restart(uint32_t length)
+{
+    DMA0->DMA[_channel].SAR = _source;
+    DMA0->DMA[_channel].DAR = _destination;
+    DMA0->DMA[_channel].DSR_BCR = length;
+    DMAMUX0->CHCFG[_channel] |= 1<<7;
+    return 0;
+}
+
+bool SimpleDMA::isBusy( int channel ) {
+    //Busy bit doesn't work as I expect it to do, so just check if counter is at zero
+    //return (DMA0->DMA[_channel].DSR_BCR & (1<<25) == 1<<25);
+    if (channel == -1)
+        channel = _channel;
+    
+    return (DMA0->DMA[channel].DSR_BCR & 0xFFFFF);
+}
+
+/*****************************************************************/
+uint32_t SimpleDMA::remaining(int channel) 
+{
+    // note that the BCR register always reads with binary 1110
+    // (if the configuration is correct) or 1111 (if there's an
+    // error in the configuration) in bits 23-20, so we need
+    // to mask these out - only keep bits 19-0 (low-order 20 
+    // bits = 0xFFFFF)
+    return (DMA0->DMA[channel < 0 ? _channel : channel].DSR_BCR & 0xFFFFF);
+}
+
+/*****************************************************************/
+void SimpleDMA::irq_handler(void) {
+    DMAMUX0->CHCFG[_channel] = 0;
+    DMA0->DMA[_channel].DSR_BCR |= DMA_DSR_BCR_DONE_MASK ; 
+    _callback.call();
+}
+
+void SimpleDMA::irq_handler0( void ) {
+    if (irq_owner[0]!=NULL)
+        irq_owner[0]->irq_handler();
+}
+
+void SimpleDMA::irq_handler1( void ) {
+    if (irq_owner[1]!=NULL)
+        irq_owner[1]->irq_handler();
+}
+
+void SimpleDMA::irq_handler2( void ) {
+    if (irq_owner[2]!=NULL)
+        irq_owner[2]->irq_handler();
+}
+
+void SimpleDMA::irq_handler3( void ) {
+    if (irq_owner[3]!=NULL)
+        irq_owner[3]->irq_handler();
+}
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SimpleDMA/SimpleDMA_KL46.h	Mon Feb 15 20:30:32 2016 +0000
@@ -0,0 +1,48 @@
+#if defined TARGET_KL46Z
+
+#define DMA_CHANNELS        4
+#define DMA_IRQS            4
+
+enum SimpleDMA_Trigger {
+    Trigger_ALWAYS = 60,
+    Trigger_UART0_RX = 2,
+    Trigger_UART0_TX,
+    Trigger_UART1_RX,
+    Trigger_UART1_TX,
+    Trigger_UART2_RX,
+    Trigger_UART2_TX,
+    Trigger_I2S0_RX = 14,
+    Trigger_I2S0_TX,
+    Trigger_SPI0_RX = 16,
+    Trigger_SPI0_TX,
+    Trigger_SPI1_RX,
+    Trigger_SPI1_TX,
+    Trigger_I2C0 = 22,
+    Trigger_I2C1,
+    Trigger_TPM0_C0,
+    Trigger_TPM0_C1,
+    Trigger_TPM0_C2,
+    Trigger_TPM0_C3,
+    Trigger_TPM0_C4,
+    Trigger_TPM0_C5,
+    Trigger_TPM1_C0 = 32,
+    Trigger_TPM1_C1,
+    Trigger_TPM2_C0,
+    Trigger_TPM2_C1,
+    Trigger_ADC0 = 40,
+    Trigger_CMP0 = 42,
+    Trigger_DAC0 = 45,
+    Trigger_PORTA = 49,
+    Trigegr_PORTC = 51,
+    Trigger_PORTD = 52,
+    Trigger_TPM0 = 54,
+    Trigger_TPM1,
+    Trigger_TPM2,
+    Trigger_TSI,
+    Trigger_ALWAYS0 = 60,
+    Trigger_ALWAYS1,
+    Trigger_ALWAYS2,
+    Trigger_ALWAYS3,
+};    
+
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SimpleDMA/SimpleDMA_LPC1768.cpp	Mon Feb 15 20:30:32 2016 +0000
@@ -0,0 +1,110 @@
+#ifdef TARGET_LPC1768
+
+#include "SimpleDMA.h"
+
+SimpleDMA *SimpleDMA::irq_owner[8] = {NULL};
+LPC_GPDMACH_TypeDef *LPC_GPDMACH[8] = {LPC_GPDMACH0, LPC_GPDMACH1, LPC_GPDMACH2, LPC_GPDMACH3, LPC_GPDMACH4, LPC_GPDMACH5, LPC_GPDMACH6, LPC_GPDMACH7};
+uint32_t getTransferType(SimpleDMA_Trigger trig, uint32_t source, uint32_t destination);
+
+SimpleDMA::SimpleDMA(int channel) {
+    this->channel(channel);
+    
+    //Power up
+    LPC_SC->PCONP |= 1<<29;
+    LPC_GPDMA->DMACConfig = 1;
+    trigger(Trigger_ALWAYS);
+    
+    NVIC_SetVector(DMA_IRQn, (uint32_t)&irq_handler0);
+    NVIC_EnableIRQ(DMA_IRQn);          
+}
+
+int SimpleDMA::start(uint32_t length) {
+    if (auto_channel)
+        _channel = getFreeChannel();
+    else
+        while(isBusy());
+    
+    uint32_t control = (source_inc << 26) | (destination_inc << 27) | (1UL << 31);
+    switch (source_size) {
+        case 16:
+            control |= (1<<18) | (length >> 1);
+            break;
+        case 32:
+            control |= (2<<18) | (length >> 2);  
+            break;
+        default:
+            control |= length;
+    }
+    switch (destination_size) {
+        case 16:
+            control |= (1<<21);
+            break;
+        case 32:
+            control |= (2<<21);  
+            break;
+    } 
+    
+    LPC_GPDMACH[_channel]->DMACCSrcAddr = _source;
+    LPC_GPDMACH[_channel]->DMACCDestAddr = _destination;
+    LPC_GPDMACH[_channel]->DMACCLLI = 0;
+    LPC_GPDMACH[_channel]->DMACCControl = control;     //Enable interrupt also
+    
+    irq_owner[_channel] = this;
+    
+    if (_trigger != Trigger_ALWAYS) {      
+        if (_trigger & 16) 
+            LPC_SC->DMAREQSEL |= 1 << (_trigger - 24);
+        else
+            LPC_SC->DMAREQSEL &= ~(1 << (_trigger - 24));
+        
+        LPC_GPDMACH[_channel]->DMACCConfig = ((_trigger & 15) << 1) + ((_trigger & 15) << 6) + (getTransferType(_trigger, _source, _destination) << 11) +  (1<<15) +1;        //Both parts of the transfer get triggered at same time
+    } else 
+        LPC_GPDMACH[_channel]->DMACCConfig = (getTransferType(_trigger, _source, _destination) << 11) + 1 + (1<<15);               //Enable channel
+    
+    return 0;
+}
+
+bool SimpleDMA::isBusy( int channel ) {
+    if (channel == -1)
+        channel = _channel;
+    return (LPC_GPDMA->DMACEnbldChns & (1<<channel));
+}
+
+void SimpleDMA::irq_handler0(void) {
+    while(LPC_GPDMA->DMACIntTCStat != 0) {
+        
+    uint32_t intloc = 31 - __CLZ(LPC_GPDMA->DMACIntTCStat & 0xFF);
+    if (irq_owner[intloc]!=NULL)
+        irq_owner[intloc]->irq_handler();
+    }
+}
+
+void SimpleDMA::irq_handler(void) {
+    LPC_GPDMA->DMACIntTCClear = 1<<_channel;
+    _callback.call();
+}
+
+static inline bool isMemory(uint32_t addr)
+{
+    return (addr >> 28) == 0 || (addr >> 28) == 1 || ((addr >= 0x2007C000) && (addr < (0x2007C000 + 0x8000)));
+}
+
+uint32_t getTransferType(SimpleDMA_Trigger trig, uint32_t source, uint32_t destination) {
+    //If it is always, simply put it on memory-to-memory
+    if (trig == Trigger_ALWAYS)
+        return 0;
+    else if (isMemory(source)) {       //if source is RAM/Flash
+        if (isMemory(destination))        //if destination is RAM/flash
+            return 3;                                                               //Return p2p for m2m with a trigger (since I have no idea wtf you are trying to do)
+        else
+            return 1;                                                               //Source is memory, destination is peripheral, so m2p
+        }
+    else {
+        if (isMemory(destination))
+            return 2;                                                               //Source is peripheral, destination is memory
+        else
+            return 3;                                                               //Both source and destination are peripherals
+        }
+        
+}
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SimpleDMA/SimpleDMA_LPC1768.h	Mon Feb 15 20:30:32 2016 +0000
@@ -0,0 +1,34 @@
+#ifdef TARGET_LPC1768
+
+#define DMA_CHANNELS        8
+#define DMA_IRQS            1
+
+enum SimpleDMA_Trigger {
+    Trigger_ALWAYS = -1,
+    Trigger_SSP0_TX,
+    Trigger_SSP0_RX,
+    Trigger_SSP1_TX,
+    Trigger_SSP1_RX,
+    Trigger_ADC,
+    Trigger_I2S0,
+    Trigger_I2S1,
+    Trigger_DAC,
+    Trigger_UART0_TX,
+    Trigger_UART0_RX,
+    Trigger_UART1_TX,
+    Trigger_UART1_RX,
+    Trigger_UART2_TX,
+    Trigger_UART2_RX,
+    Trigger_UART3_TX,
+    Trigger_UART3_RX,
+    Trigger_MATCH0_0 = 24,
+    Trigger_MATCH0_1,
+    Trigger_MATCH1_0,
+    Trigger_MATCH1_1,
+    Trigger_MATCH2_0,
+    Trigger_MATCH2_1,
+    Trigger_MATCH3_0,
+    Trigger_MATCH3_1
+};  
+
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SimpleDMA/SimpleDMA_common.cpp	Mon Feb 15 20:30:32 2016 +0000
@@ -0,0 +1,25 @@
+#include "SimpleDMA.h"
+
+void SimpleDMA::channel(int chan) {
+    if (chan == -1) {
+        auto_channel = true;
+        _channel = 0;
+    } else {
+        auto_channel = false;
+        if (chan >= 0 && chan < DMA_CHANNELS)
+            _channel = chan;
+        else
+            _channel = DMA_CHANNELS-1;
+    }
+}
+
+int SimpleDMA::getFreeChannel(void) {
+    int retval = 0;
+    while(1) {
+        if (!isBusy(retval))
+            return retval;
+        retval++;
+        if (retval >= DMA_CHANNELS)
+            retval = 0;
+    }  
+}
\ No newline at end of file

--- a/TSL1410R/tsl1410r.h	Sun Feb 07 03:07:11 2016 +0000
+++ b/TSL1410R/tsl1410r.h	Mon Feb 15 20:30:32 2016 +0000
@@ -1,3 +1,45 @@
+// DMA VERSION - NOT WORKING
+
+// I'm saving this code for now, since it was somewhat promising but doesn't
+// quite work.  The idea here was to read the ADC via DMA, operating the ADC
+// in continuous mode.  This speeds things up pretty impressively (by about 
+// a factor of 3 vs having the MCU read each result from the ADC sampling 
+// register), but I can't figure out how to get a stable enough signal out of 
+// it.  I think the problem is that the timing isn't precise enough in detecting 
+// when the DMA completes each write.  We have to clock the next pixel onto the 
+// CCD output each time we complete a sample, and we have to do so quickly so 
+// that the next pixel charge is stable at the ADC input pin by the time the 
+// ADC sample interval starts.  I'm seeing a ton of noise, which I think means 
+// that the new pixel isn't ready for the ADC in time. 
+//
+// I've tried a number of approaches, none of which works:
+//
+// - Skip every other sample, so that we can spend one whole sample just 
+// clocking in the next pixel.  We discard the "odds" samples that are taken
+// during pixel changes, and use only the "even" samples where the pixel is
+// stable the entire time.  I'd think the extra sample would give us plenty
+// of time to stabilize the next pixel, but it doesn't seem to work out that
+// way.  I think the problem might be that the latency of the MCU responding
+// to each sample completion is long enough relative to the sampling interval
+// that we can't reliably respond to the ADC done condition fast enough.  I've
+// tried basing the sample completion detection on the DMA byte counter and
+// the ADC interrupt.  The DMA byte counter is updated after the DMA transfer
+// is done, so that's probably just too late in the cycle.  The ADC interrupt
+// should be concurrent with the DMA transfer starting, but in practice it 
+// still doesn't give us good results.
+//
+// - Use DMA, but with the ADC in single-sample mode.  This bypasses the latency
+// problem by ensuring that the ADC doesn't start a new sample until we've
+// definitely finished clocking in the next pixel.  But it defeats the whole
+// purpose by eliminating the speed improvement - the speeds are comparable to
+// doing the transfers via the MCU.  This surprises me because I'd have expected
+// that the DMA would run concurrently with the MCU pixel clocking code, but
+// maybe there's enough bus contention between the MCU and DMA in this case that
+// there's no true overlapping of the operation.  Or maybe the interrupt dispatch
+// adds enough overhead to negate any overlapping.  I haven't actually been able
+// to get good data out of this mode, either, but I gave up early because of the
+// lack of any speed improvement.
+
 /*
  *  TSL1410R interface class.
  *
@@ -7,9 +49,11 @@
 #include "mbed.h"
 #include "config.h"
 #include "AltAnalogIn.h"
+#include "SimpleDMA.h"
  
 #ifndef TSL1410R_H
 #define TSL1410R_H
+#define TSL1410R_DMA
 
 // For faster GPIO on the clock pin, we write the IOPORT registers directly.
 // PORT_BASE gives us the memory mapped location of the IOPORT register set
@@ -49,11 +93,29 @@
         clear();
         clear();
         
+        // set up our DMA channel for reading from our analog in pin
+        ao1.initDMA(&adc_dma);
+        
+        // Set up our DMA channel for writing the sensor SCLK - we use the PTOR
+        // (toggle) register to flip the bit on each write.  To pad the timing
+        // to the rate required by the CCD, do a no-op 0 write to PTOR after
+        // each toggle.  This gives us a 16-byte buffer, which we can make
+        // circular in the DMA controller.
+        static const uint32_t clkseq[] = { clockMask, 0, clockMask, 0 };
+        clk_dma.destination(&clockPort->PTOR, false, 32);
+        clk_dma.source(clkseq, true, 32, 16);   // set up our circular source buffer
+        clk_dma.trigger(Trigger_ADC0);          // software trigger
+        clk_dma.setCycleSteal(false);           // do the entire transfer on each trigger
+        
         totalTime = 0.0; nRuns = 0; // $$$
     }
     
     float totalTime; int nRuns; // $$$
 
+    // ADC interrupt handler - on each ADC event, 
+    static TSL1410R *instance;
+    static void _aiIRQ() { }
+
     // Read the pixels.
     //
     // 'n' specifies the number of pixels to sample, and is the size of
@@ -91,11 +153,10 @@
     // the current pixels and start a fresh integration cycle.
     void read(register uint16_t *pix, int n)
     {
-        Timer t; t.start(); // $$$
+        Timer t; t.start(); //float tDMA, tPix; // $$$
         
         // get the clock pin pointers into local variables for fast access
-        register volatile uint32_t *clockPSOR = &clockPort->PSOR;
-        register volatile uint32_t *clockPCOR = &clockPort->PCOR;
+        register volatile uint32_t *clockPTOR = &clockPort->PTOR;
         register const uint32_t clockMask = this->clockMask;
         
         // start the next integration cycle by pulsing SI and one clock
@@ -111,8 +172,6 @@
 static int done=0;
 if (done++ == 0) printf("nPixSensor=%d, n=%d, skip=%d, parallel=%d\r\n", nPixSensor, n, skip, parallel);
 
-        // get the clock PSOR and PCOR register addresses for fast access
-
         // read all of the pixels
         int dst;
         if (parallel)
@@ -125,7 +184,7 @@
                 // Take the clock high.  The TSL1410R will connect the next
                 // pixel pair's hold capacitors to the A01 and AO2 lines 
                 // (respectively) on the clock rising edge.
-                *clockPSOR = clockMask;
+                *clockPTOR = clockMask;
 
                 // Start the ADC sampler for AO1.  The TSL1410R sample 
                 // stabilization time per the data sheet is 120ns.  This is
@@ -135,7 +194,7 @@
                 ao1.start();
                 
                 // take the clock low while we're waiting for the reading
-                *clockPCOR = clockMask;
+                *clockPTOR = clockMask;
                 
                 // Read the first half-sensor pixel from AO1
                 pix[dst] = ao1.read_u16();
@@ -152,46 +211,61 @@
                 // Clock through the skipped pixels
                 for (int i = skip ; i > 0 ; --i) 
                 {
-                    *clockPSOR = clockMask;
-                    *clockPCOR = clockMask;
+                    *clockPTOR = clockMask;
+                    *clockPTOR = clockMask;
+                    *clockPTOR = 0;         // pad the timing with an extra nop write
                 }
             }
         }
         else
         {
             // serial mode - read all pixels in a single file
-            for (dst = 0 ; dst < n ; ++dst)
+
+            // clock in the first pixel
+            clock = 1;
+            clock = 0;
+            
+            // start the ADC DMA transfer
+            ao1.startDMA(pix, n, true);
+            
+            // We do 4 clock PTOR writes per clocked pixel (the skipped pixels 
+            // plus the pixel we actually want to sample), at 32 bits (4 bytes) 
+            // each, giving 16 bytes per pixel for the overall write.
+            int clk_dma_len = (skip+1)*16;
+            clk_dma.start(clk_dma_len);
+            
+            // start the first sample
+            ao1.start();
+            
+            // read all pixels
+            for (dst = n*2 ; dst > 0 ; dst -= 2)
             {
-                // Clock the next pixel onto the sensor A0 line
-                *clockPSOR = clockMask;
+                // wait for the current ADC sample to finish
+                while (adc_dma.remaining() >= dst) { }
                 
-                // start the ADC sampler
+                // start the next analog read while we're finishing the DMA transfers
                 ao1.start();
                 
-                // take the clock low while we're waiting for the analog reading
-                *clockPCOR = clockMask;
-                
-                // wait for and read the ADC sample; plug it into the output
-                // array, and increment the output pointer to the next position
-                pix[dst] = ao1.read_u16();
-                
-                // clock through the skipped pixels
-                for (int i = skip ; i > 0 ; --i) 
-                {
-                    *clockPSOR = clockMask;
-                    *clockPCOR = clockMask;
-                }
+                // re-arm the clock DMA
+                //clk_dma.restart(clk_dma_len);
             }
+            
+            // wait for the DMA transfer to finish
+            while (adc_dma.isBusy()) { }
+            
+            // apply the 12-bit to 16-bit rescaling to all values
+            for (int i = 0 ; i < n ; ++i)
+                pix[i] <<= 4;
         }
         
 //$$$
 if (done==1) printf(". done: dst=%d\r\n", dst);
         
         // clock out one extra pixel to leave A1 in the high-Z state
-        clock = 1;
-        clock = 0;
+        *clockPTOR = clockMask;
+        *clockPTOR = clockMask;
         
-        if (n >= 80) { totalTime += t.read(); nRuns += 1; } // $$$
+        if (n >= 64) { totalTime += t.read(); nRuns += 1; } // $$$
     }
 
     // Clock through all pixels to clear the array.  Pulses SI at the
@@ -222,6 +296,9 @@
     }
 
 private:
+    SimpleDMA adc_dma;        // DMA controller for reading the analog input
+    SimpleDMA clk_dma;        // DMA controller for the sensor SCLK (writes the PTOR register to toggle the clock bit)
+    char *dmabuf;             // buffer for DMA transfers
     int nPixSensor;           // number of pixels in physical sensor array
     DigitalOut si;            // GPIO pin for sensor SI (serial data) 
     DigitalOut clock;         // GPIO pin for sensor SCLK (serial clock)
@@ -233,3 +310,4 @@
 };
  
 #endif /* TSL1410R_H */
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TSL1410R/tsl1410r_dma.cpp	Mon Feb 15 20:30:32 2016 +0000
@@ -0,0 +1,8 @@
+#include "tsl1410r.h"
+
+#ifdef TSL1410R_DMA
+
+// interrupt counters
+uint32_t TSL1410R::intCounter;
+
+#endif

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TSL1410R/tsl1410r_orig.h	Mon Feb 15 20:30:32 2016 +0000
@@ -0,0 +1,238 @@
+/*
+ *  TSL1410R interface class.
+ *
+ *  This provides a high-level interface for the Taos TSL1410R linear CCD array sensor.
+ */
+ 
+#include "mbed.h"
+#include "config.h"
+#include "AltAnalogIn.h"
+ 
+#ifndef TSL1410R_H
+#define TSL1410R_H
+
+// For faster GPIO on the clock pin, we write the IOPORT registers directly.
+// PORT_BASE gives us the memory mapped location of the IOPORT register set
+// for a pin; PINMASK gives us the bit pattern to write to the registers.
+//
+// - To turn a pin ON:  PORT_BASE(pin)->PSOR |= PINMASK(pin)
+// - To turn a pin OFF: PORT_BASE(pin)->PCOR |= PINMASK(pin)
+// - To toggle a pin:   PORT_BASE(pin)->PTOR |= PINMASK(pin)
+//
+// When used in a loop where the port address and pin mask are cached in
+// local variables, this runs at the same speed as the FastIO library - about 
+// 78ns per pin write on the KL25Z.  Not surprising since it's doing the same
+// thing, and the compiler should be able to reduce a pin write to a single ARM
+// instruction when the port address and mask are in local register variables.
+// The advantage over the FastIO library is that this approach allows for pins
+// to be assigned dynamically at run-time, which we prefer because it allows for
+// configuration changes to be made on the fly rather than having to recompile
+// the program.
+#define GPIO_PORT(pin)        (((unsigned int)(pin)) >> PORT_SHIFT)
+#define GPIO_PORT_BASE(pin)   ((FGPIO_Type *)(FPTA_BASE + GPIO_PORT(pin) * 0x40))
+#define GPIO_PINMASK(pin)     gpio_set(pin)
+ 
+class TSL1410R
+{
+public:
+    TSL1410R(int nPixSensor, PinName siPin, PinName clockPin, PinName ao1Pin, PinName ao2Pin) 
+        : nPixSensor(nPixSensor), si(siPin), clock(clockPin), ao1(ao1Pin), ao2(ao2Pin)
+    {
+        // we're in parallel mode if ao2 is a valid pin
+        parallel = (ao2Pin != NC);
+        
+        // remember the clock pin port base and pin mask for fast access
+        clockPort = GPIO_PORT_BASE(clockPin);
+        clockMask = GPIO_PINMASK(clockPin);
+        
+        // clear out power-on random data by clocking through all pixels twice
+        clear();
+        clear();
+        
+        totalTime = 0.0; nRuns = 0; // $$$
+    }
+    
+    float totalTime; int nRuns; // $$$
+    
+    // Read the pixels.
+    //
+    // 'n' specifies the number of pixels to sample, and is the size of
+    // the output array 'pix'.  This can be less than the full number
+    // of pixels on the physical device; if it is, we'll spread the
+    // sample evenly across the full length of the device by skipping
+    // one or more pixels between each sampled pixel to pad out the
+    // difference between the sample size and the physical CCD size.
+    // For example, if the physical sensor has 1280 pixels, and 'n' is
+    // 640, we'll read every other pixel and skip every other pixel.
+    // If 'n' is 160, we'll read every 8th pixel and skip 7 between
+    // each sample.
+    // 
+    // The reason that we provide this subset mode (where 'n' is less
+    // than the physical pixel count) is that reading a pixel is the most
+    // time-consuming part of the scan.  For each pixel we read, we have
+    // to wait for the pixel's charge to transfer from its internal smapling
+    // capacitor to the CCD's output pin, for that charge to transfer to
+    // the KL25Z input pin, and for the KL25Z ADC to get a stable reading.
+    // This all takes on the order of 20us per pixel.  Skipping a pixel
+    // only requires a clock pulse, which takes about 350ns.  So we can
+    // skip 60 pixels in the time it takes to sample 1 pixel.
+    //
+    // We clock an SI pulse at the beginning of the read.  This starts the
+    // next integration cycle: the pixel array will reset on the SI, and 
+    // the integration starts 18 clocks later.  So by the time this method
+    // returns, the next sample will have been integrating for npix-18 clocks.  
+    // That's usually enough time to allow immediately reading the next
+    // sample.  If more integration time is required, the caller can simply
+    // sleep/spin for the desired additional time, or can do other work that
+    // takes the desired additional time.
+    //
+    // If the caller has other work to tend to that takes longer than the
+    // desired maximum integration time, it can call clear() to clock out
+    // the current pixels and start a fresh integration cycle.
+    void read(register uint16_t *pix, int n)
+    {
+        Timer t; t.start();//$$$
+        
+        // get the clock pin pointers into local variables for fast access
+        register volatile uint32_t *clockPSOR = &clockPort->PSOR;
+        register volatile uint32_t *clockPCOR = &clockPort->PCOR;
+        register const uint32_t clockMask = this->clockMask;
+        
+        // start the next integration cycle by pulsing SI and one clock
+        si = 1;
+        clock = 1;
+        si = 0;
+        clock = 0;
+        
+        // figure how many pixels to skip on each read
+        int skip = nPixSensor/n - 1;
+        
+///$$$
+static int done=0;
+if (done++ == 0) printf("nPixSensor=%d, n=%d, skip=%d, parallel=%d\r\n", nPixSensor, n, skip, parallel);
+
+        // read all of the pixels
+        int dst;
+        if (parallel)
+        {
+            // Parallel mode - read pixels from each half sensor concurrently.
+            // Divide 'n' (the output pixel count) by 2 to get the loop count,
+            // since we're going to do 2 pixels on each iteration.
+            for (n /= 2, dst = 0 ; dst < n ; ++dst)
+            {
+                // Take the clock high.  The TSL1410R will connect the next
+                // pixel pair's hold capacitors to the A01 and AO2 lines 
+                // (respectively) on the clock rising edge.
+                *clockPSOR = clockMask;
+
+                // Start the ADC sampler for AO1.  The TSL1410R sample 
+                // stabilization time per the data sheet is 120ns.  This is
+                // fast enough that we don't need an explicit delay, since
+                // the instructions to execute this call will take longer
+                // than that.
+                ao1.start();
+                
+                // take the clock low while we're waiting for the reading
+                *clockPCOR = clockMask;
+                
+                // Read the first half-sensor pixel from AO1
+                pix[dst] = ao1.read_u16();
+                
+                // Read the second half-sensor pixel from AO2, and store it
+                // in the destination array at the current index PLUS 'n',
+                // which you will recall contains half the output pixel count.
+                // This second pixel is halfway up the sensor from the first 
+                // pixel, so it goes halfway up the output array from the
+                // current output position.
+                ao2.start();
+                pix[dst + n] = ao2.read_u16();
+                
+                // Clock through the skipped pixels
+                for (int i = skip ; i > 0 ; --i) 
+                {
+                    *clockPSOR = clockMask;
+                    *clockPCOR = clockMask;
+                }
+            }
+        }
+        else
+        {
+            // serial mode - read all pixels in a single file
+
+            // clock in the first pixel
+            *clockPSOR = clockMask;
+            *clockPCOR = clockMask;
+            
+            // clock through the pixels            
+            for (dst = 0 ; dst < n ; ++dst)
+            {
+                // Read this sample
+                ao1.start();
+                pix[dst] = ao1.read_u16();
+                
+                // clock in the next pixel
+                for (int i = skip ; i >= 0 ; --i) 
+                {
+                    *clockPSOR = clockMask;
+                    *clockPCOR = clockMask;
+                    *clockPCOR = clockMask;
+                }
+            }
+
+            // we're done - stop the ADC sampler            
+            ao1.stop();
+        }
+        
+//$$$
+//static int xxx = 0; xxx = (xxx+1)%2500; if (xxx==0) printf("tPix=%f, tDMA=%f, diff=%f\r\n", tPix*1000, tDMA*1000, (tDMA - tPix)*1000);
+if (done==1) printf(". done: dst=%d\r\n", dst);
+        
+        // clock out one extra pixel to leave A1 in the high-Z state
+        clock = 1;
+        clock = 0;
+        
+        if (n >= 64) { totalTime += t.read(); nRuns += 1; } // $$$
+    }
+
+    // Clock through all pixels to clear the array.  Pulses SI at the
+    // beginning of the operation, which starts a new integration cycle.
+    // The caller can thus immediately call read() to read the pixels 
+    // integrated while the clear() was taking place.
+    void clear()
+    {
+        // get the clock pin pointers into local variables for fast access
+        register FGPIO_Type *clockPort = this->clockPort;
+        register uint32_t clockMask = this->clockMask;
+
+        // clock in an SI pulse
+        si = 1;
+        clockPort->PSOR = clockMask;
+        si = 0;
+        clockPort->PCOR = clockMask;
+        
+        // if in serial mode, clock all pixels across both sensor halves;
+        // in parallel mode, the pixels are clocked together
+        int n = parallel ? nPixSensor/2 : nPixSensor;
+        
+        // clock out all pixels
+        for (int i = 0 ; i < n + 1 ; ++i) {
+            clock = 1; // $$$clockPort->PSOR = clockMask;
+            clock = 0; // $$$clockPort->PCOR = clockMask;
+        }
+    }
+
+private:
+    SimpleDMA dma;            // DMA controller for reading the analog input
+    char *dmabuf;             // buffer for DMA transfers
+    int nPixSensor;           // number of pixels in physical sensor array
+    DigitalOut si;            // GPIO pin for sensor SI (serial data) 
+    DigitalOut clock;         // GPIO pin for sensor SCLK (serial clock)
+    FGPIO_Type *clockPort;    // IOPORT base address for clock pin - cached for fast writes
+    uint32_t clockMask;       // IOPORT register bit mask for clock pin
+    AltAnalogIn ao1;          // GPIO pin for sensor AO1 (analog output 1) - we read sensor data from this pin
+    AltAnalogIn ao2;          // GPIO pin for sensor AO2 (analog output 2) - 2nd sensor data pin, when in parallel mode
+    bool parallel;            // true -> running in parallel mode (we read AO1 and AO2 separately on each clock)
+};
+ 
+#endif /* TSL1410R_H */
+

--- a/ccdSensor.h	Sun Feb 07 03:07:11 2016 +0000
+++ b/ccdSensor.h	Mon Feb 15 20:30:32 2016 +0000
@@ -200,20 +200,23 @@
         return true;
     }
     
-    // send an exposure report to the joystick interface
-    virtual void sendExposureReport(USBJoystick &js)
+    // Send an exposure report to the joystick interface.
+    // 
+    // Mode bits:
+    //    0x01  -> send processed pixels (default is raw pixels)
+    //    0x02  -> low res scan (default is high res scan)
+    virtual void sendExposureReport(USBJoystick &js, uint8_t mode)
     {
-        // Read a fresh high-res scan, then do another right away.  This
-        // gives us the shortest possible exposure for the sample we report,
-        // which helps ensure that the user inspecting the data sees something
-        // close to what we see when we calculate the plunger position.
-        ccd.read(pix, highResPix);
-        ccd.read(pix, highResPix);
+        // get the number of pixels according to the high res/low res mode
+        int npix = (mode & 0x02 ? lowResPix : highResPix);
+
+        // do a scan
+        ccd.read(pix, npix);
         
         // send reports for all pixels
         int idx = 0;
-        while (idx < highResPix)
-            js.updateExposure(idx, highResPix, pix);
+        while (idx < npix)
+            js.updateExposure(idx, npix, pix);
             
         // The pixel dump requires many USB reports, since each report
         // can only send a few pixel values.  An integration cycle has
@@ -226,7 +229,8 @@
     }
     
 protected:
-    // pixel buffer - we allocate this to be big enough for a high-res scan
+    // Pixel buffer.  We allocate this to be big enough for the high-res scan,
+    // which is the most pixels we'll need to capture.
     uint16_t *pix;
 
     // number of pixels in a high-res scan
@@ -252,7 +256,7 @@
 {
 public:
     PlungerSensorTSL1410R(PinName si, PinName clock, PinName ao1, PinName ao2) 
-        : PlungerSensorCCD(1280, 320, 64, si, clock, ao1, ao2)
+        : PlungerSensorCCD(1280, 256, 80, si, clock, ao1, ao2)
     {
     }
 };
@@ -262,7 +266,7 @@
 {
 public:
     PlungerSensorTSL1412R(PinName si, PinName clock, PinName ao1, PinName ao2)
-        : PlungerSensorCCD(1536, 384, 64, si, clock, ao1, ao2)
+        : PlungerSensorCCD(1536, 256, 128, si, clock, ao1, ao2)
     {
     }
 };

--- a/main.cpp	Sun Feb 07 03:07:11 2016 +0000
+++ b/main.cpp	Mon Feb 15 20:30:32 2016 +0000
@@ -2326,8 +2326,12 @@
 // to distinguish special request reply packets.
 uint16_t statusFlags;
     
-// flag: send a pixel dump after the next read
+// Pixel dump mode - the host requested a dump of image sensor pixels
+// (helpful for installing and setting up the sensor and light source)
 bool reportPix = false;
+uint8_t reportPixMode;  // pixel report mode bits: 
+                        // 0x01 -> raw pixels (0) / processed (1)
+                        // 0x02 -> high res scan (0) / low res (1)
 
 
 // ---------------------------------------------------------------------------
@@ -2508,8 +2512,11 @@
             
         case 3:
             // 3 = pixel dump
-            // (No parameters)
+            //     data[2] = mode bits:
+            //               0x01  -> return processed pixels (default is raw pixels)
+            //               0x02  -> low res scan (default is high res scan)
             reportPix = true;
+            reportPixMode = data[2];
             
             // show purple until we finish sending the report
             diagLED(1, 0, 1);
@@ -3390,7 +3397,7 @@
         if (reportPix)
         {
             // send the report            
-            plungerSensor->sendExposureReport(js);
+            plungerSensor->sendExposureReport(js, reportPixMode);
 
             // we have satisfied this request
             reportPix = false;

--- a/plunger.h	Sun Feb 07 03:07:11 2016 +0000
+++ b/plunger.h	Mon Feb 15 20:30:32 2016 +0000
@@ -50,7 +50,17 @@
     // through special joystick reports.  This is used for PC-side testing tools
     // to let the user check the sensor installation by directly viewing its
     // pixel output.
-    virtual void sendExposureReport(class USBJoystick &js) { }
+    //
+    // Mode bits:
+    //   0x01  -> send processed pixels (default is raw pixels)
+    //   0x02  -> low res scan (default is high res scan)
+    //
+    // If processed mode is selected, the sensor should apply any pixel
+    // processing it normally does when taking a plunger position reading,
+    // such as exposure correction, noise reduction, etc.  In raw mode, we
+    // simply send the pixels as read from the sensor.  Both modes are useful
+    // in setting up the physical sensor.
+    virtual void sendExposureReport(class USBJoystick &js, uint8_t mode) { }
 };
 
 #endif /* PLUNGER_H */