Class similar to AnalogIn that uses burst mode to run continious background conversions so when the input is read, the last value can immediatly be returned.

Fork of FastAnalogIn by Erik -

Obsolete!

Has been already merged with Erik's original repository => take the original!

  • Added support for LPC4088.
  • Fixed linker error (missing definition of static member "channel_usage")

Files at this revision

API Documentation at this revision

Comitter:
humlet
Date:
Sun Apr 20 16:23:19 2014 +0000
Parent:
3:a9b753c25073
Child:
5:55274430c8df
Commit message:
Added support for LPC4088,; Fixed linker error (missing definition of static member)

Changed in this revision

FastAnalogIn.h Show annotated file Show diff for this revision Revisions of this file
FastAnalogIn_LPC1768.cpp Show annotated file Show diff for this revision Revisions of this file
FastAnalogIn_LPC408X.cpp Show annotated file Show diff for this revision Revisions of this file
--- a/FastAnalogIn.h	Sat Mar 08 16:01:36 2014 +0000
+++ b/FastAnalogIn.h	Sun Apr 20 16:23:19 2014 +0000
@@ -7,7 +7,7 @@
 #include "mbed.h"
 #include "pinmap.h"
 
-#if !defined TARGET_LPC1768 && !defined TARGET_KL25Z && !defined TARGET_KL46Z && !defined TARGET_KL05Z
+#if !defined TARGET_LPC1768 && !defined TARGET_KL25Z && !defined TARGET_KL46Z && !defined TARGET_KL05Z && !defined TARGET_LPC408X
     #error "Target not supported"
 #endif
 
@@ -107,7 +107,7 @@
     float read( void )
     {
         unsigned short value = read_u16();
-        return (float)value/65535;
+        return (float)value * (1.0f/65535.0f);
     }
     
     /** An operator shorthand for read()
--- a/FastAnalogIn_LPC1768.cpp	Sat Mar 08 16:01:36 2014 +0000
+++ b/FastAnalogIn_LPC1768.cpp	Sun Apr 20 16:23:19 2014 +0000
@@ -18,6 +18,8 @@
     NC,    NC,     0
 };
 
+int FastAnalogIn::channel_usage[8] = {0,0,0,0,0,0,0,0};
+
 FastAnalogIn::FastAnalogIn(PinName pin, bool enabled)
 {
     ADCnumber = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FastAnalogIn_LPC408X.cpp	Sun Apr 20 16:23:19 2014 +0000
@@ -0,0 +1,128 @@
+#ifdef TARGET_LPC408X
+
+#include "FastAnalogIn.h"
+
+static inline int div_round_up(int x, int y)
+{
+    return (x + (y - 1)) / y;
+}
+
+static const PinMap PinMap_ADC[] = {
+    {P0_23, ADC0_0, 0x01},
+    {P0_24, ADC0_1, 0x01},
+    {P0_25, ADC0_2, 0x01},
+    {P0_26, ADC0_3, 0x01},
+    {P1_30, ADC0_4, 0x03},
+    {P1_31, ADC0_5, 0x03},
+    {P0_12, ADC0_6, 0x03},
+    {P0_13, ADC0_7, 0x03},
+    {NC   , NC    , 0   }
+};
+
+int FastAnalogIn::channel_usage[8] = {0,0,0,0,0,0,0,0};
+
+FastAnalogIn::FastAnalogIn(PinName pin, bool enabled)
+{
+    ADCnumber = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
+    if (ADCnumber == (uint32_t)NC)
+        error("ADC pin mapping failed");
+    //printf("ADC_ID=%u\n",ADCnumber);
+    datareg = (uint32_t*) (&LPC_ADC->DR[ADCnumber]);
+
+    wait_us(1000); // we need either the debug printf above or a wait before we try to initialize the ADC
+
+    // ensure power is turned on
+    LPC_SC->PCONP |= (1 << 12);
+
+    uint32_t PCLK = PeripheralClock;
+
+    // calculate minimum clock divider
+    //  clkdiv = divider - 1
+    uint32_t MAX_ADC_CLK = 12400000;
+    uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1;
+    // Set the clkdiv
+    LPC_ADC->CR &= ~(255<<8);
+    LPC_ADC->CR |= clkdiv<<8;
+
+    //Enable ADC:
+    LPC_ADC->CR |= 1<<21;
+
+    //Enable burstmode, set start as zero
+    LPC_ADC->CR |= 1<<16;
+    LPC_ADC->CR &= ~(7<<24);
+
+    // must enable analog mode (ADMODE = 0)   ... ???  just copied from official LPC408X analogin_api.c
+    __IO uint32_t *reg = (__IO uint32_t*) (LPC_IOCON_BASE + 4 * pin);
+    *reg &= ~(1 << 7);
+
+    //Map pins
+    pinmap_pinout(pin, PinMap_ADC);
+
+    //Enable channel
+    running = false;
+    enable(enabled);
+
+}
+
+void FastAnalogIn::enable(bool enabled)
+{
+    //If currently not running
+    if (!running) {
+        if (enabled) {
+            //Enable the ADC channel
+            channel_usage[ADCnumber]++;
+            LPC_ADC->CR |= (1<<ADCnumber);
+            running = true;
+        } else
+            disable();
+    }
+}
+
+void FastAnalogIn::disable( void )
+{
+    //If currently running
+    if (running) {
+        channel_usage[ADCnumber]--;
+        
+        if (channel_usage[ADCnumber]==0)
+            LPC_ADC->CR &= ~(1<<ADCnumber);
+    }
+    running = false;
+}
+
+unsigned short FastAnalogIn::read_u16( void )
+{
+    volatile unsigned int retval;
+    //If object is enabled return current value of datareg
+    if (running ){
+        retval = *datareg;
+    //If it isn't running, enable it and wait until new value is written to datareg
+    }else {
+        //Force a read to clear done bit, enable the ADC channel
+        retval = *datareg;
+        enable();
+        //Wait until it is converted
+        while(1) {
+            wait_us(1);
+            retval = *datareg;
+            if ((retval>>31) == 1)
+                break;
+        }
+        //Do a second conversion since first one always fails for some reason
+        while(1) {
+            wait_us(1);
+            retval = *datareg;
+            if ((retval>>31) == 1)
+                break;
+        }
+        //Disable again
+        disable();
+    }
+    
+    //Do same thing as standard mbed lib, unused bit 0-3, replicate 4-7 in it
+    retval &= ~0xFFFF000F;
+    retval |= (retval >> 8) & 0x000F;
+    return retval;
+
+}
+#endif //defined TARGET_LPC408X