Revision 0:055897ab699b, committed 2011-01-16

Comitter:

AjK

Date:

Sun Jan 16 18:27:44 2011 +0000

Child:

1:46c8c60e744a

Commit message:

1.0 Initial release

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX3100.cpp	Sun Jan 16 18:27:44 2011 +0000
@@ -0,0 +1,324 @@
+/*
+    Copyright (c) 2011 Andy Kirkham
+ 
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+ 
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+ 
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+*/
+
+#include "MAX3100.h"
+
+namespace AjK {
+
+void 
+MAX3100::init(PinName mosi, PinName miso, PinName sclk, PinName cs, PinName irq, SPI *spi) 
+{
+    config = 0;
+    flushTxBuffer();
+    flushRxBuffer();
+    
+    _parity = 0;
+    
+    _cs_function = NULL;
+    _cs_obj      = NULL;
+    _cs_method   = NULL;
+    
+    if (cs != NC) {    
+        _cs = new DigitalOut(cs);
+        _cs->write( 1 );
+    }
+    else _cs = (DigitalOut *)NULL;
+                
+    if (spi) {
+        _spi = spi;
+    }
+    else {                
+        _spi = new SPI(mosi, miso, sclk);
+        _spi->format(16, 0);
+        _spi->frequency(MAX3100_SPI_FREQ);
+    }
+    
+    if (irq != NC) {    
+        _irq = new InterruptIn(irq);
+        _irq->mode(PullUp);
+        topic_1498(irq);       
+        _irq->fall(this, &MAX3100::isr);
+    }
+    else { _irq = (InterruptIn *)NULL; }
+        
+    baud(10); // 9600baud by default.
+}
+
+void 
+MAX3100::cs_value(int i)
+{
+    if (_cs != (DigitalOut *)NULL) _cs->write(i & 1); 
+    else {
+        if (_cs_function != NULL) (*_cs_function)(_device, i & 1);
+        else {
+            if (_cs_obj && _cs_method) (_cs_obj->*_cs_method)(_device, i & 1);
+        }
+    }
+}
+    
+uint16_t 
+MAX3100::spiwrite(uint16_t val) 
+{
+    cs_value(0);
+    uint16_t r = _spi->write(val);
+    cs_value(1);
+    return r;
+}
+
+uint16_t 
+MAX3100::config_write(uint16_t val) 
+{
+    return spiwrite(MAX3100_CONF_WR | val); 
+}
+
+uint16_t 
+MAX3100::config_read(void)          
+{ 
+    return spiwrite(MAX3100_CONF_RD);     
+}
+
+
+void 
+MAX3100::baud(int baudrate) 
+{        
+    __disable_irq();
+    config &= ~(0xf);
+    config |= (baudrate & 0xf);
+    config_write(config);
+    __enable_irq();
+}
+    
+void 
+MAX3100::enableRxIrq(void) 
+{ 
+    __disable_irq();
+    config &= ~MAX3100_RM(1);
+    config |=  MAX3100_RM(1);
+    config_write(config); 
+    __enable_irq();
+}
+    
+void 
+MAX3100::disableRxIrq(void) 
+{ 
+    __disable_irq();
+    config &= ~MAX3100_RM(1);
+    config_write(config);     
+    __enable_irq();
+}
+    
+void 
+MAX3100::enableTxIrq(void) 
+{ 
+    __disable_irq();
+    config &= ~MAX3100_TM(1);
+    config |=  MAX3100_TM(1);
+    config_write(config); 
+    __enable_irq();
+}
+    
+void 
+MAX3100::disableTxIrq(void) 
+{ 
+    __disable_irq();
+    config &= ~MAX3100_TM(1);
+    config_write(config);     
+    __enable_irq();
+}
+        
+int 
+MAX3100::putc(int c) 
+{ 
+    uint16_t data, conf;
+
+    // If no space return -1 as an error code.    
+    if (tx_buffer_full) return -1;
+
+    if (_parity) {
+        int pBit = parityCal(c & 0xFF);        
+        if (_parity == Even && pBit == 0) { c |= (1 << 8); }
+        if (_parity == Odd  && pBit == 1) { c |= (1 << 8); }
+    }
+    else { c &= 0xFF; }
+    
+    // Function is non-interruptable by the MAX3100 class
+    // to avoid SPI bus contention between writing a byte
+    // in user context (here) and IRQ context.    
+    __disable_irq();
+
+    conf = config_read();
+        
+    if (tx_buffer_in == tx_buffer_out && conf & MAX3100_CONF_T) {
+        data = spiwrite(MAX3100_DATA_WR | (c & 0x1FF));              
+        // In case we get a byte while writing store it away.
+        if (!rx_buffer_full && data & MAX3100_CONF_R) {
+            rx_buffer[rx_buffer_in++] = (uint16_t)(data & 0xFF);
+            if (rx_buffer_in >= MAX3100_RX_BUFFER_SIZE) rx_buffer_in = 0;
+            if (rx_buffer_in == rx_buffer_out) rx_buffer_full = true;
+        }
+    }
+    else {
+        tx_buffer[tx_buffer_in++] = (char)(c & 0xFF);
+        if (tx_buffer_in >= MAX3100_TX_BUFFER_SIZE) {
+            tx_buffer_in = 0;
+        }
+        if (tx_buffer_in == tx_buffer_out) tx_buffer_full = true;
+    }
+    
+    __enable_irq();
+        
+    return 1;
+}
+
+void
+MAX3100::puts(char *s) {
+    char *q = s;
+    while(*(q)) {
+        if (putc((int)(*(q))) == -1) return;
+        q++;
+    }
+}
+
+int 
+MAX3100::getc(void) { 
+    if (!rx_buffer_full && rx_buffer_in == rx_buffer_out) return -1;
+    int c = (int)((unsigned char)rx_buffer[rx_buffer_out++]);
+    if (rx_buffer_out >= MAX3100_RX_BUFFER_SIZE) rx_buffer_out = 0;
+    rx_buffer_full = false;
+    return c;
+}
+
+char *
+MAX3100::gets(char *s, int size)
+{
+    int i;
+    char *q = s;
+    while(size) { 
+        do { i = getc(); } while (i == -1); // Blocks!
+        *(q) = (char)i; size--; 
+    }
+    return s; 
+}
+
+int 
+MAX3100::peek(void) { 
+    if (!rx_buffer_full && rx_buffer_in == rx_buffer_out) return -1;
+    return (int)((unsigned char)rx_buffer[rx_buffer_out]);
+}
+
+void 
+MAX3100::isr(void) {
+    uint16_t data = spiwrite(MAX3100_DATA_RD);
+    bool tx_ready = data & MAX3100_CONF_T ? true : false;
+        
+    // The MAX3100 does have an RX fifo. So attempt to empty it into the RX buffer.
+    do {
+        if (!rx_buffer_full && data & MAX3100_CONF_R) {
+            rx_buffer[rx_buffer_in++] = (char)(data & 0xFF);
+            if (rx_buffer_in >= MAX3100_RX_BUFFER_SIZE) rx_buffer_in = 0;
+            if (rx_buffer_in == rx_buffer_out) rx_buffer_full = true;
+        }
+    }
+    while ((data = spiwrite(MAX3100_DATA_RD)) & MAX3100_CONF_R);
+        
+    // The MAX3100 doesn't have a hardware TX fifo, so just test to see if it's TX buffer
+    // is empty. If it is and we have bytes in the TX buffer then send one now.
+    if (tx_ready && (tx_buffer_full || tx_buffer_in != tx_buffer_out)) {
+        data = spiwrite(MAX3100_DATA_WR | (tx_buffer[tx_buffer_out++] & 0x1FF));
+        if (tx_buffer_out >= MAX3100_TX_BUFFER_SIZE) tx_buffer_out = 0;
+        tx_buffer_full = false;                                        
+    }
+        
+    // In case we get a byte while sending then store it.
+    if (!rx_buffer_full && data & MAX3100_CONF_R) {
+        rx_buffer[rx_buffer_in++] = (char)(data & 0xFF);
+        if (rx_buffer_in >= MAX3100_RX_BUFFER_SIZE) rx_buffer_in = 0;
+        if (rx_buffer_in == rx_buffer_out) rx_buffer_full = true;
+    }        
+}
+
+void 
+MAX3100::setStopBits(int i) 
+{
+    switch(i) {
+        case 1: 
+            __disable_irq();
+            config &= ~(1 << 6);
+            config_write(config);     
+            __enable_irq();
+            break;
+        case 2: 
+            __disable_irq();
+            config |= (1 << 6);
+            config_write(config);     
+            __enable_irq();
+            break;    
+    }
+}
+
+int 
+MAX3100::parityCal(uint8_t c)
+{
+    int count = 0;
+    for (int mask = 1, i = 0; i < 8; i++, mask = mask << 1) {
+        if (c & mask) count++;
+    }
+    return count & 1;
+}
+        
+void 
+MAX3100::topic_1498(PinName p) {
+    // http://mbed.org/forum/bugs-suggestions/topic/1498
+    uint32_t clr0 = 0, clr2 = 0;
+        
+    switch( p ) {
+        case p5:  clr0 = (1UL << 9); break;
+        case p6:  clr0 = (1UL << 8); break;
+        case p7:  clr0 = (1UL << 7); break;
+        case p8:  clr0 = (1UL << 6); break;
+        case p9:  clr0 = (1UL << 0); break;
+        case p10: clr0 = (1UL << 1); break;
+        case p11: clr0 = (1UL << 18); break;
+        case p12: clr0 = (1UL << 17); break;
+        case p13: clr0 = (1UL << 15); break;
+        case p14: clr0 = (1UL << 16); break;
+        case p15: clr0 = (1UL << 23); break;
+        case p16: clr0 = (1UL << 24); break;
+        case p17: clr0 = (1UL << 25); break;
+        case p18: clr0 = (1UL << 26); break;
+        case p21: clr2 = (1UL << 5); break;
+        case p22: clr2 = (1UL << 4); break;
+        case p23: clr2 = (1UL << 3); break;
+        case p24: clr2 = (1UL << 2); break;
+        case p25: clr2 = (1UL << 1); break;
+        case p26: clr2 = (1UL << 0); break;
+        case p27: clr0 = (1UL << 11); break;
+        case p28: clr0 = (1UL << 10); break;
+        case p29: clr0 = (1UL << 5); break;
+        case p30: clr0 = (1UL << 4); break;        
+    }
+        
+    if (clr0) LPC_GPIOINT->IO0IntClr = clr0;
+    if (clr2) LPC_GPIOINT->IO2IntClr = clr2;            
+}
+
+}; // namespace AjK ends

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX3100.h	Sun Jan 16 18:27:44 2011 +0000
@@ -0,0 +1,314 @@
+/*
+    Copyright (c) 2011 Andy Kirkham
+ 
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+ 
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+ 
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+*/
+
+
+#ifndef AJK_MAX31000_H
+#define AJK_MAX31000_H
+
+#ifndef MBED_H
+#include "mbed.h"
+#endif
+
+#ifndef MAX3100_TX_BUFFER_SIZE
+#define MAX3100_TX_BUFFER_SIZE  32
+#endif
+
+#ifndef MAX3100_RX_BUFFER_SIZE
+#define MAX3100_RX_BUFFER_SIZE  32
+#endif
+
+#ifndef MAX3100_SPI_FREQ
+#define MAX3100_SPI_FREQ    5000000
+#endif
+
+#define MAX3100_CONF_WR     (3U << 14)
+#define MAX3100_CONF_RD     (1U << 14)
+#define MAX3100_CONF_T      (1U << 14)
+#define MAX3100_CONF_R      (1U << 15)
+#define MAX3100_FEN(x)      (x << 13)
+#define MAX3100_SHDNi(x)    (x << 12)
+#define MAX3100_TM(x)       (x << 11)
+#define MAX3100_RM(x)       (x << 10)
+#define MAX3100_PM(x)       (x <<  9)
+#define MAX3100_RAM(x)      (x <<  8)
+#define MAX3100_IR(x)       (x <<  7)
+#define MAX3100_ST(x)       (x <<  6)
+#define MAX3100_PE(x)       (x <<  5)
+#define MAX3100_L(x)        (x <<  4)
+#define MAX3100_BAUD(x)     (x <<  0)        
+
+#define MAX3100_DATA_WR     (2U << 14)
+#define MAX3100_DATA_RD     (0)
+#define MAX3100_TE(x)       (x << 10)
+#define MAX3100_RAFE(x)     (x << 10)
+#define MAX3100_RTS(x)      (x <<  9)
+#define MAX3100_CTS(x)      (x <<  9)
+#define MAX3100_PT(x)       (x <<  8)
+#define MAX3100_PR(x)       (x <<  8)
+
+namespace AjK {
+
+class MAX3100Dummy;
+
+/** MAX3100 An external serial IO device.
+ *
+ * The MAX3100 librray is designed to allow the easy attachment of additional
+ * serial ports to the Mbed. We all know that the Mbed already has 3 potential
+ * serial ports. But maybe you need more ports or maybe you need to use the Mbed
+ * pins for an alternative function. The MAX3100 may well be able to help in 
+ * situations like these. 
+ *
+ * Each MAX3100 device you create in is TX/RX buffered with 32 characters in a circular
+ * buffer system.
+ *
+ * The MAX3100 uses at least one Mbed SPI port and additional DigitalOut and InterruptIn
+ * pins to work. However, you can attach multiple MAX3100 devices to a single SPI "bus".
+ *
+ * For more information on attaching multiple devices see all the examples listed below.
+ *
+ * @see example1.h
+ * @see example2.h
+ * @see example3.h
+ * @see http://pdfserv.maxim-ic.com/en/ds/MAX3100.pdf
+ */
+class MAX3100 : public Stream {
+
+protected:
+    
+    SPI         *_spi;
+    DigitalOut  *_cs;
+    InterruptIn *_irq;
+    
+    uint16_t tx_buffer[MAX3100_TX_BUFFER_SIZE];
+    int  tx_buffer_in;
+    int  tx_buffer_out;
+    bool tx_buffer_full;
+    
+    uint16_t rx_buffer[MAX3100_RX_BUFFER_SIZE];
+    int  rx_buffer_in;
+    int  rx_buffer_out;
+    bool rx_buffer_full;
+    
+    uint16_t    config;
+    int         _device;
+    int         _parity;
+    
+    virtual int _putc(int c) { return putc(c); }
+    virtual int _getc()      { return getc(); }
+
+    /** init
+     *
+     * Initialise the device.
+     * @param PinName SPI mosi
+     * @param PinName SPI miso
+     * @param PinName SPI sclk
+     * @param PinName DigitalOut cs
+     * @param PinName InterruptIn irq
+     * @param SPI * A pointer to a shared SPI bus
+     */
+    void init(PinName mosi, PinName miso, PinName sclk, PinName cs, PinName irq, SPI *spi = (SPI *)NULL);    
+    
+    uint16_t spiwrite(uint16_t val);        
+    uint16_t config_write(uint16_t val);
+    uint16_t config_read(void);
+
+    // C style callback function pointer for external CS control.    
+    void (*_cs_function)(int, int); 
+    
+    // C++ style callback method pointer for external CS control
+    MAX3100Dummy  *_cs_obj;
+    void (MAX3100Dummy::*_cs_method)(int, int);
+
+    // Internal CS control.
+    void cs_value(int);
+    
+    // calculate byte parity.
+    int parityCal(uint8_t c);
+    
+    // http://mbed.org/forum/bugs-suggestions/topic/1498
+    void topic_1498(PinName p); 
+
+public:
+    
+    /** Constructor
+     */
+    MAX3100() { error( "No pins supplied to constructor" ); }
+    
+    /** Constructor
+     */
+    MAX3100(PinName mosi, PinName miso, PinName sclk, PinName cs, PinName irq, int device = 0) {
+        _device = device;
+        init( mosi, miso, sclk, cs, irq);
+    }
+    
+    /** Constructor
+     */
+    MAX3100(SPI *spi, PinName cs, PinName irq, int device = 0) {
+        _device = device;
+        init( NC, NC, NC, cs, irq, spi);
+    }
+    
+    /** Destructor
+     */
+    virtual ~MAX3100() { 
+        if ( _spi )     delete( _spi );
+        if ( _irq )     delete( _irq );
+        if ( _cs  )     delete( _cs );
+    }
+
+    enum Parity {
+        None = 0
+        , Odd
+        , Even
+        , Forced1   
+        , Forced0
+    };    
+    
+    /** setParity
+     *
+     * Set the parity of the system. Default is None.
+     *
+     * @param Parity None, Odd, Even
+     */
+    void setParity(int p) { _parity = p; }
+    
+    /** setStopBits
+     *
+     * Set the number of stop bits. Default is One.
+     *
+     * @param int 1 or 2
+     */
+    void setStopBits(int i);
+    
+    /** System interrupt service routine.
+     */
+    void isr(void);
+    
+    /** baud
+     * Set the system baud. Default is "10" (9600). Note,
+     * this is not like Mbed's Serial where you pass the
+     * baud rate you want. The MAX3100 has 16 possible 
+     * preset prescalers you can choose from. See the datasheet
+     * for more info. 
+     *
+     * @see http://pdfserv.maxim-ic.com/en/ds/MAX3100.pdf
+     * @param int A number from 0 to 15 indicating which prescaler to use.
+     */
+    void baud(int baudrate);
+    
+    /** enableRxIrq
+     */
+    void enableRxIrq(void);
+    
+    /** disableRxIrq
+     */
+    void disableRxIrq(void);
+    
+    /** enableTxIrq
+     */
+    void enableTxIrq(void);
+    
+    /** disableTxIrq
+     */
+    void disableTxIrq(void);
+    
+    /** putc
+     * @param int c The byte to write.
+     */
+    int  putc(int c);
+    
+    /** puts
+     * @param char * The string to print.
+     */
+    void puts(char *s);
+    
+    /** getc
+     * @return int c The byte read or -1 if no bytes to read.
+     */
+    int  getc(void); 
+    
+    /** gets
+     * Get a string. Note, this method blocks until size bytes are read.
+     * @param char *s where to place the incoming bytes.
+     * @param int size How many bytes to read.
+     * @return char * The value of *s passed in.
+     */
+    char *gets(char *s, int size);   
+    
+    /** peek
+     * like getc() but does NOT remove the byte from the buffer.
+     * @see getc*(
+     */
+    int  peek(void);
+    
+    /** readable
+     * Are any byte(s) available in the RX buffer?
+     * @return 0 if none, 1 otherwise.
+     */
+    int  readable(void) { return (rx_buffer_in != rx_buffer_out || rx_buffer_full) ? 1 : 0; }
+    
+    /** writable
+     * Can we write a byte to teh serial stream?
+     * @return non-zero if we can, zero otherwise.
+     */
+    int  writable(void) { return tx_buffer_full ? 0 : 1; }
+    
+    /** setDevice
+     * Give this device an "address".
+     * @param int i An address to use in callbacks.
+     */
+    void setDevice(int i) { _device = i; }
+    
+    /** flushTxBuffer
+     *
+     * Flush the TX buffer.
+     */
+    void flushTxBuffer(void) { tx_buffer_in = tx_buffer_out = 0; tx_buffer_full = false; }
+    
+    /** flushRxBuffer
+     *
+     * Flush the RX buffer.
+     */
+    void flushRxBuffer(void) { rx_buffer_in = rx_buffer_out = 0; rx_buffer_full = false; }
+    
+    /** attach_cs
+     * Attach a C style callback function pointer. Used if an external function
+     * is controlling the chip CS line.
+     * @param function A C function pointer
+     */
+    void attach_cs(void (*function)(int, int) = 0) { _cs_function = function; }
+    
+    /** attach_cs
+     * Attach a C++ object/method pointer. Used if an external function
+     * @param object An object that conatins the callback method.
+     * @param method The method within the object to call.
+     */
+    template<class T> 
+    void attach_cs(T* item, void (T::*method)(int, int)) { _cs_obj = (MAX3100Dummy *)item; _cs_method = (void (MAX3100Dummy::*)(int, int))method; }
+    
+};
+
+}; // namespace AjK ends.
+
+using namespace AjK;
+
+#endif

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/example1.h	Sun Jan 16 18:27:44 2011 +0000
@@ -0,0 +1,72 @@
+/*
+    Copyright (c) 2011 Andy Kirkham
+ 
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+ 
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+ 
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+*/
+
+#ifdef MAX3100_EXAMPLE_COMPILE
+
+/*
+ * Connecting up the MAX3100 for this test program. Note, to form a "loopback"
+ * the MAX3100 TX pin (13) is connected to the RX pin (12). Don't forget thwe Xtal
+ * and power pins that are not shown here. Although I do PullUp mode on the IRQ pin
+ * I still needed a real external pull up resistor on the IRQ line. You may need one
+ * also.
+ *                                    ____________
+ *                                   /            \
+ * Mbed MOSI p5 |-----------------> 1| Din     TX | 13 ------\
+ *      MISO p6 |-----------------> 2| Dout       |          |
+ *      SCLK p7 |-----------------> 3| Sclk    RX | 12 ------/
+ *           p8 |-----------------> 4| CS         |
+ *           p9 |-----------------> 5| IRQ        | MAX3100
+ *                      +5v ------> 6| SHTD       | Xtal and PWR not shown.
+ *                                   \____________/
+ */
+
+#include "mbed.h"
+#include "MAX3100.h"
+
+Serial  pc(USBTX, USBRX);
+MAX3100 max(p5, p6, p7, p8, p9);
+
+int main() {
+    
+    // Set the PC USB serial baud rate.
+    pc.baud(115200);
+    
+    max.enableRxIrq();
+    max.enableTxIrq();
+    
+    max.printf("\nHello World.\n");
+    
+    // Any byte received on the "USB serial port" is sent to the MAX3100 device.
+    // Any byte received by the MAX3100 device is sent to the "USB serial port".
+    while (1) {
+        if (pc.readable()) {
+            int c = pc.getc();
+            while (!max.writable());
+            max.putc(c);            
+        }
+        if (max.readable()) {
+            pc.putc( max.getc() );
+        }
+    }    
+}
+
+#endif

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/example2.h	Sun Jan 16 18:27:44 2011 +0000
@@ -0,0 +1,103 @@
+/*
+    Copyright (c) 2011 Andy Kirkham
+ 
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+ 
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+ 
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+*/
+
+#ifdef MAX3100_EXAMPLE_COMPILE
+
+/*
+ * Connecting up the MAX3100 for this test program. Note, to form a "loopback"
+ * the MAX3100 TX pin (13) is connected to the RX pin (12). Don't forget thwe Xtal
+ * and power pins that are not shown here. Although I do PullUp mode on the IRQ pin
+ * I still needed a real external pull up resistor on the IRQ lines. You may need to
+ * add two pullups to teh two interrupt lines at p9 and p11.
+ *                                          ____________
+ *                                         /            \ U1
+ * Mbed MOSI p5 |-------*---------------> 1| Din     TX | 13 ------\
+ *      MISO p6 |-----*-|---------------> 2| Dout       |          |
+ *      SCLK p7 |---*-|-|---------------> 3| Sclk    RX | 12 ------/
+ *           p8 |---|-|-|---------------> 4| CS         |
+ *           p9 |---|-|-|---------------> 5| IRQ        | MAX3100 
+ *                  | | |        +5v ---> 6| SHTD       | Xtal and PWR not shown.
+ *                  | | |                  \____________/
+ *                  | | |                   ____________
+ *                  | | |                  /            \ U2
+ *                  | | \---------------> 1| Din     TX | 13 ------\
+ *                  | \-----------------> 2| Dout       |          |
+ *                  \-------------------> 3| Sclk    RX | 12 ------/
+ *          p10 |-----------------------> 4| CS         |
+ *          p11 |-----------------------> 5| IRQ        | MAX3100
+ *                               +5v ---> 6| SHTD       | Xtal and PWR not shown.
+ *                                         \____________/
+ *
+ * This example shows two MAX3100 sharing a single SPI bus. Each device, however, 
+ * still has it's own CS and IRQ signals.
+ */
+
+#include "mbed.h"
+#include "MAX3100.h"
+
+Serial  pc(USBTX, USBRX);
+SPI     spi(p5, p6, p7);
+MAX3100 *max1;
+MAX3100 *max2;
+
+int main() {
+        
+    // Set the PC USB serial baud rate.
+    pc.baud(115200);
+
+    // Format the SPI interface.    
+    spi.format(16, 0);
+    spi.frequency(MAX3100_SPI_FREQ);
+    
+    // Create the two MAX3100 objects which share the SPI bus.
+    max1 = new MAX3100(&spi, p8, p9);
+    max2 = new MAX3100(&spi, p10, p11);
+    
+    // Enable the interrupts.
+    max1->enableRxIrq();
+    max1->enableTxIrq();
+    max2->enableRxIrq();
+    max2->enableTxIrq();
+    
+    max1->printf("\nHello World.\n");
+    max2->printf("\nHello World.\n");
+    
+    // Any byte received on the "USB serial port" is sent to both MAX3100 devices.
+    // Any byte received by a MAX3100 device is sent to the "USB serial port".
+    while (1) {
+        if (pc.readable()) {
+            int c = pc.getc();
+            while (!max1->writable());
+            max1->putc(c);            
+            while (!max2->writable());
+            max2->putc(c);            
+        }
+        if (max1->readable()) {
+            pc.putc( max1->getc() );
+        }
+        if (max2->readable()) {
+            pc.putc( max2->getc() );
+        }
+    }    
+}
+
+#endif

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/example3.h	Sun Jan 16 18:27:44 2011 +0000
@@ -0,0 +1,153 @@
+/*
+    Copyright (c) 2011 Andy Kirkham
+ 
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+ 
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+ 
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+*/
+
+#ifdef MAX3100_EXAMPLE_COMPILE
+
+/*
+ * NOTE! Unlike examples 1 & 2 (which are tested in the real world) this example
+ * is theoretical only as I have not tested it. It should work but if you try it 
+ * and it doesn't work let me know! It's shown here as a starting point to demo
+ * how to share multiple MAX3100 interrupts and address multiple chips using
+ * external hardware to manage each MAX3100's CS signal.
+ * 
+ * Connecting up the MAX3100 for this test program. Note, to form a "loopback"
+ * the MAX3100 TX pin (13) is connected to the RX pin (12). Don't forget thwe Xtal
+ * and power pins that are not shown here. Although I do PullUp mode on the IRQ pin
+ * I still needed a real external pull up resistor on the IRQ line. You may need one
+ * also.
+ *
+ *                      __________
+ *                     /          \
+ *      Mbed p8 |---> 1| A0    Y0 | 15 -----> MAX0
+ *           p9 |---> 2| A1    Y1 | 14 -----> MAX1
+ *          p10 |---> 3| A2    Y2 | 13 -----> MAX2
+ *          p11 |---> 5| CS3   Y3 | 12 -----> MAX3 (and on to MAX7)
+ *                     \__________/ TTL138 (Tie CS1 to +ve and CS2 to 0v)
+ *
+ *                                          ____________
+ *                                         /            \ U1
+ * Mbed MOSI p5 |-------*---------------> 1| Din     TX | 13 ------\
+ *      MISO p6 |-----*-|---------------> 2| Dout       |          |
+ *      SCLK p7 |---*-|-|---------------> 3| Sclk    RX | 12 ------/
+ *                  | | |        MAX0 --> 4| CS         |
+ *          p12 |-*-|-|-|---------------> 5| IRQ        | MAX3100 
+ *                | | | |        +5v ---> 6| SHTD       | Xtal and PWR not shown.
+ *                | | | |                  \____________/
+ *                | | | |                   ____________
+ *                | | | |                  /            \ U2
+ *                | | | *---------------> 1| Din     TX | 13 ------\
+ *                | | *-|---------------> 2| Dout       |          |
+ *                | *-|-|---------------> 3| Sclk    RX | 12 ------/
+ *                | | | |        MAX1 --> 4| CS         |
+ *                *-|-|-|---------------> 5| IRQ        | MAX3100
+ *                | | | |        +5v ---> 6| SHTD       | Xtal and PWR not shown.
+ *                | | | |                  \____________/
+ *                | | | |                   ____________
+ *                | | | |                  /            \ U3
+ *                | | | \---------------> 1| Din     TX | 13 ------\
+ *                | | \-----------------> 2| Dout       |          |
+ *                | \-------------------> 3| Sclk    RX | 12 ------/
+ *                |              MAX2 --> 4| CS         |
+ *                \---------------------> 5| IRQ        | MAX3100
+ *                               +5v ---> 6| SHTD       | Xtal and PWR not shown.
+ *                                         \____________/
+ *
+ * Assume a further 5 MAX3100 devices connected to the bus in the same way
+ * to make a total of 8 MAX3100 serial devices connected to a single SPI bus.
+ * Additionally, they all share the same interrupt signal. This is possible 
+ * because the MAX3100 IRQ output is open drain. So you will need an external 1k
+ * pull up resistor on the IRQ signal.
+ */
+
+#include "mbed.h"
+#include "MAX3100.h"
+
+Serial       pc(USBTX, USBRX);
+SPI          spi(p5, p6, p7);
+BusOut       addr(p8, p9, p10);
+DigitalOut   cs(p11);
+InterruptIn  irq(p12);
+MAX3100      *max[8];
+
+// Class used to decode the address and handle shared interrupts.
+class MAX3100_Addr {
+public:
+    void cs_select(int device, int val) { 
+        addr = device & 0x7; // Select device.
+        cs.write(val & 1);   // Assert/deassert chip CS.
+    }
+    void isr(void) {
+        for (int i = 0; i < 8; i++) {
+            if (max[i] != (MAX3100 *)NULL) max[i]->isr();
+        }
+    }
+};
+
+MAX3100_Addr address;
+
+int main() {
+    int index;
+    
+    cs = 1;
+    
+    // Set the PC USB serial baud rate.
+    pc.baud(115200);
+
+    // Format the SPI interface.    
+    spi.format(16, 0);
+    spi.frequency(MAX3100_SPI_FREQ);
+    
+    // Create the 8 devices and set them up.
+    for (int index = 0; index < 8; index++) {
+        max[index] = new MAX3100(&spi, NC, NC);  
+        max[index]->setDevice(index);   
+        max[index]->enableRxIrq();
+        max[index]->enableTxIrq();
+        max[index]->attach_cs(&address, &MAX3100_Addr::cs_select);
+    }
+    
+    // Connect the interrupt signal.
+    irq.fall(&address, &MAX3100_Addr::isr);
+    
+    // Any byte received on the "USB serial port" is sent to all MAX3100 devices.
+    // Any byte received by a MAX3100 device is sent to the "USB serial port".
+    while (1) {
+        if (pc.readable()) {
+            int c = pc.getc();
+            for (index = 0; index < 8; index++) {
+                if (max[index] != (MAX3100 *)NULL) {
+                    while (!max[index]->writable());
+                    max[index]->putc(c);            
+                }
+            }            
+        }
+        for (index = 0; index < 8; index++) {
+            if (max[index] != (MAX3100 *)NULL) {
+                if (max[index]->readable()) {
+                    pc.putc(max[index]->getc());
+                }    
+            }
+        }        
+    }    
+}
+
+#endif