Revision 0:1116b0d151fc, committed 2013-09-21

Comitter:

wim

Date:

Sat Sep 21 19:25:09 2013 +0000

Commit message:

Extended functionality to include mbed type AnalogIn and AnalogOut; Fixed issue related to LPC812 I2C bug

Changed in this revision

diff -r 000000000000 -r 1116b0d151fc PCF8591.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PCF8591.cpp	Sat Sep 21 19:25:09 2013 +0000
@@ -0,0 +1,293 @@
+/* PCF8591 - I2C 8 bit 4 channel A/D and 8 bit 1 channel D/A converter
+ * Copyright (c) 2013 Wim Huiskamp
+ *
+ * Released under the MIT License: http://mbed.org/license/mit
+ *
+ * version 0.2 Initial Release
+*/
+#include "mbed.h"
+#include "PCF8591.h"
+
+
+/** Create a PCF8591 AD and DA object using a specified I2C bus and slaveaddress
+  *
+  * @param I2C &i2c the I2C port to connect to 
+  * @param char deviceAddress the address of the PCF8591
+  */  
+PCF8591::PCF8591(I2C *i2c, uint8_t deviceAddress) : _i2c(i2c) {
+    
+  _slaveAddress = deviceAddress;
+  _init(); 
+}
+
+
+#if(0)
+//These methods are disabled since they interfere with normal expected behaviour for mbed type Analog I/O
+//
+  
+/** Set ADC mode
+  *
+  * @param adc_mode      ADC Channel mode, valid Range (PCF8591_4S, PCF8591_3D, PCF8591_2S_1D, PCF8591_2D)
+  */  
+void PCF8591::setADCMode(uint8_t mode){
+  uint8_t data[6];
+  
+  _mode = _mode & ~PCF8591_2D; // Clear ADC mode bits
+  
+  switch (mode) {
+    case PCF8591_4S:
+                _mode = _mode | PCF8591_4S;
+                break; 
+    case PCF8591_3D:
+                _mode = _mode | PCF8591_3D;
+                break;    
+    case PCF8591_2S_1D:
+                _mode = _mode | PCF8591_2S_1D;
+                break;    
+    case PCF8591_2D:
+                _mode = _mode | PCF8591_2D;
+                break;    
+    default:
+                _mode = _mode | PCF8591_4S;    
+                break; 
+  }    
+        
+  data[0] = _mode;             // Control Reg
+  
+  // write data to the device
+  _i2c->write(_slaveAddress, (char*) data, 1);  
+   
+};
+
+/** Set DAC mode
+  *
+  * @param dac_mode      DAC Channel mode, valid Range (false=disable, true=enable)
+  */  
+void PCF8591::setDACMode(bool mode) {
+  uint8_t data[6];
+   
+  if (mode) 
+    _mode = _mode | PCF8591_AOUT;  // Enable DAC output
+  else
+    _mode = _mode & ~PCF8591_AOUT; // Disable DAC output
+
+  data[0] = _mode;             // Control Reg
+  
+  // write data to the device
+  _i2c->write(_slaveAddress, (char*) data, 1);  
+  
+};
+#endif
+
+
+/** Write Analog Output
+  *
+  * @param  analogOut  output value (0..255)
+  */  
+void PCF8591::write(uint8_t analogOut) {
+  uint8_t data[6];
+   
+  data[0] = _mode;             // Control Reg
+  data[1] = analogOut;         // DAC Channel
+  
+  // write data to the device
+  _i2c->write(_slaveAddress, (char*) data, 2);  
+};        
+
+/** Read Analog Channel 
+  *
+  * @param Channel   ADC channel, valid range PCF8591_ADC0, PCF8591_ADC1, PCF8591_ADC2 or PCF8591_ADC3
+  * @return value    uint8_t AD converted value (0..255, representing 0V..Vcc)   
+  */  
+#if(0)
+// I2C block operations test
+// Causes problems with Ticker and printf on LPC812. No issues found on LPC1768
+uint8_t PCF8591::read(uint8_t channel) {
+//  uint8_t data[6];
+  uint8_t data[6] = {123,123,123,123,123,123}; //test to check failed read
+    
+  _mode   = _mode & ~PCF8591_CHMSK;            // Clear ADC Channel bits
+  _mode   = _mode | (channel & PCF8591_CHMSK); // Set ADC Channel bits
+    
+  data[0] = _mode;             // Init Control Reg
+  
+  // write data to the device to select the ADC channel
+  _i2c->write(_slaveAddress, (char*) data, 1);  
+ 
+  // read selected ADC channel
+  // note that first byte is a 'dummy' and should be ignored
+  _i2c->read(_slaveAddress, (char*) data, 2);  
+  return data[1];
+};
+
+#else
+// I2C single byte operations test
+// No issues found on LPC812
+uint8_t PCF8591::read(uint8_t channel) {
+  uint8_t data[6];
+//  uint8_t data[6] = {123,123,123,123,123,123}; //test to check failed read
+    
+  _mode   = _mode & ~PCF8591_CHMSK;            // Clear ADC Channel bits
+  _mode   = _mode | (channel & PCF8591_CHMSK); // Set ADC Channel bits
+    
+  data[0] = _mode;             // Init Control Reg
+  
+  // write data to the device to select the ADC channel
+  _i2c->start();  
+  _i2c->write(_slaveAddress);        // Slave write address 
+  _i2c->write(data[0]);  
+  _i2c->stop();  
+   
+  // read selected ADC channel
+  // note that first byte is a 'dummy' and should be ignored
+  _i2c->start();  
+  _i2c->write(_slaveAddress | 0x01); // Slave read address 
+  data[0]=_i2c->read(1);  //ack
+  data[1]=_i2c->read(0);  //nack  
+  _i2c->stop();  
+  
+  return data[1];
+};
+
+#endif
+
+
+/** Initialise AD and DA driver 
+  *
+  */  
+void PCF8591::_init() {
+  uint8_t data[6];
+  
+  _mode   = PCF8591_CTRL_DEF;  // Init mode
+  
+  data[0] = _mode;             // Init Control Reg
+  data[1] = 0x00;              // Init DAC Channel to 0
+  
+  // write data to the device
+  _i2c->write(_slaveAddress, (char*) data, 2);  
+}; 
+
+
+
+
+
+/** Create a PCF8591 AnalogOut object connected to the specified I2C bus and deviceAddress
+ *
+ */
+PCF8591_AnalogOut::PCF8591_AnalogOut(I2C *i2c, uint8_t deviceAddress) : _i2c(i2c) {
+    
+  _slaveAddress = deviceAddress;
+  _init(); 
+}
+ 
+
+/** Write Analog Output
+  *
+  * @param  analogOut value (0 .. 1.0)
+  */  
+void PCF8591_AnalogOut::write(float analogOut) {
+  uint8_t data[6];
+
+  data[0] = _mode;             // Control Reg
+
+  // DAC Channel
+  if (analogOut < 0.0) data[1] = 0;
+  else if (analogOut >= 1.0) data[1] = 255;
+       else data[1] = uint8_t (analogOut * 255.0);      
+   
+  // write data to the device
+  _i2c->write(_slaveAddress, (char*) data, 2);  
+};        
+
+/** Operator = Analog Output
+  *
+  * @param  analogOut value (0.0f .. 1.0f)
+  */  
+PCF8591_AnalogOut& PCF8591_AnalogOut::operator= (float value){  
+  write(value);     
+  return *this;   
+}
+ 
+
+/** Initialise DAC driver 
+  *
+  */  
+void PCF8591_AnalogOut::_init() {
+  uint8_t data[6];
+  
+  _mode   = PCF8591_CTRL_DEF;  // Init mode
+  
+  data[0] = _mode;             // Init Control Reg
+  data[1] = 0x00;              // Init DAC Channel to 0
+  
+  // write data to the device
+  _i2c->write(_slaveAddress, (char*) data, 2);  
+}; 
+
+
+
+/** Create a PCF8591 AnalogIn object connected to the specified I2C bus and deviceAddress
+ *
+ */
+PCF8591_AnalogIn::PCF8591_AnalogIn(I2C *i2c, uint8_t channel, uint8_t deviceAddress) : _i2c(i2c) {
+    
+  _slaveAddress = deviceAddress;
+  _channel = channel;  
+  _init(); 
+}
+ 
+
+/** Read Analog input
+  *
+  * @return analogIn value (0 .. 1.0)
+  */  
+float PCF8591_AnalogIn::read() {
+  uint8_t data[6];
+    
+  data[0] = _mode;             // Init Control Reg
+  
+  // write data to the device to select the ADC channel
+  _i2c->start();  
+  _i2c->write(_slaveAddress);        // Slave write address 
+  _i2c->write(data[0]);  
+  _i2c->stop();  
+   
+  // read selected ADC channel
+  // note that first byte is a 'dummy' and should be ignored
+  _i2c->start();  
+  _i2c->write(_slaveAddress | 0x01); // Slave read address 
+  data[0]=_i2c->read(1);  //ack
+  data[1]=_i2c->read(0);  //nack  
+  _i2c->stop();  
+  
+ 
+  // ADC Channel
+  return ((float) data[1] / 255.0);       
+  
+};
+
+
+/** Operator float Analog Input
+  *
+  * @return analogIn value (0 .. 1.0)
+  */  
+PCF8591_AnalogIn::operator float(){
+  return (read());    
+}
+ 
+
+/** Initialise ADC driver 
+  *
+  */  
+void PCF8591_AnalogIn::_init() {
+  uint8_t data[6];
+  
+  _mode   = PCF8591_CTRL_DEF;  // Init mode
+  _mode   = _mode & ~PCF8591_CHMSK;             // Clear ADC Channel bits
+  _mode   = _mode | (_channel & PCF8591_CHMSK); // Set ADC Channel bits
+      
+  data[0] = _mode;             // Init Control Reg
+  
+  // write data to the device
+  _i2c->write(_slaveAddress, (char*) data, 1);  
+}; 

diff -r 000000000000 -r 1116b0d151fc PCF8591.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PCF8591.h	Sat Sep 21 19:25:09 2013 +0000
@@ -0,0 +1,221 @@
+/* PCF8591 - I2C 8 bit, 4 channel A/D and 8 bit, 1 channel D/A converter
+ * Copyright (c) 2013 Wim Huiskamp
+ *
+ * Released under the MIT License: http://mbed.org/license/mit
+ *
+ * version 0.2 Initial Release
+*/
+#ifndef _PCF8591_H
+#define _PCF8591_H
+
+/** Driver for PCF8591 I2C I2C A/D and D/A converter
+ *
+ * @code
+ * #include "mbed.h"
+ * #include "PCF8591.h"
+ * 
+ * // I2C Communication
+ * I2C i2c_adcdac(p28,p27); // SDA, SCL for LPC1768
+ * //I2C i2c_adcdac(P0_10,P0_11); // SDA, SCL for LPC812
+ *
+ * //Declare a composite ADC and DAC device that may be used through public methods
+ * PCF8591 adc_dac(&i2c_adcdac); // I2C bus, Default PCF8591 Slaveaddress
+ *
+ * //Declare independent ADC and DAC objects that may be used similar to mbed AnalogIn and AnalogOut pins
+ * //PCF8591_AnalogOut anaOut(&i2c_bus);
+ * //
+ * //PCF8591_AnalogIn anaIn(&i2c_bus, PCF8591_ADC0);
+ *
+ * 
+ * int main() {
+ *   uint8_t count = 0; 
+ *   uint8_t analog;  
+ *
+ *   while(1) {
+ *     wait(0.2);    
+ *     count++;       
+ *
+ *     // Composite device methods    
+ *     adc_dac.write(count);                 // write D/A value
+ *     analog = adc_dac.read(PCF8591_ADC0);  // read A/D value for Channel 0
+ * 
+ *     // mbed pin type methods    
+ *     //anaOut = (float)count / 255.0;        // write D/A value using range 0.0f .. 1.0f
+ *     //analog = anaIn * 33.0;                // read A/D value for Channel 0 in (Volts*10)
+ *   }
+ *  
+ * }
+ * @endcode
+ */
+
+
+//Address Defines for PCF8591
+#define PCF8591_SA0 0x90
+#define PCF8591_SA1 0x92
+#define PCF8591_SA2 0x94
+#define PCF8591_SA3 0x96
+#define PCF8591_SA4 0x98
+#define PCF8591_SA5 0x9A
+#define PCF8591_SA6 0x9C
+#define PCF8591_SA7 0x9E
+
+//Register Defines for PCF8591
+#define PCF8591_CTRL 0x00
+#define PCF8591_ADR0 0x01
+#define PCF8591_ADR1 0x02
+#define PCF8591_ADR2 0x03
+#define PCF8591_ADR3 0x04
+#define PCF8591_DAR  0x01
+
+//Control Register Defines for PCF8591
+//AD Channels
+#define PCF8591_ADC0 0x00
+#define PCF8591_ADC1 0x01
+#define PCF8591_ADC2 0x02
+#define PCF8591_ADC3 0x03
+//AD Channel Mask
+#define PCF8591_CHMSK   0x03
+
+//Auto Increment flag (0=disable, 1=enable)
+#define PCF8591_AIF  0x04
+
+//AD Channels Input modes
+//4 Single Channels (Chan0=AIN0, Chan1=AIN0, Chan2=AIN0, Chan3=AIN0)
+#define PCF8591_4S   0x00
+//3 Diff Channels (Chan0=AIN0-AIN3, Chan1=AIN1-AIN3, Chan2=AIN2-AIN3)
+#define PCF8591_3D   0x10
+//2 Single Channels (Chan0=AIN0, Chan1=AIN1)
+//1 Diff Channel    (Chan2=AIN2-AIN3)
+#define PCF8591_2S_1D 0x20
+//2 Diff Channels (Chan0=AIN0-AIN1, Chan1=AIN2-AIN3)
+#define PCF8591_2D   0x30
+//ChannelMode Mask
+#define PCF8591_CHMDMSK  0x30
+
+//Analog Output enable flag (0=disable, 1=enable)
+#define PCF8591_AOUT 0x40
+
+//Default Mode: ADC0, AutoIncr Off, 4 Single Chan, AnalogOut On
+#define PCF8591_CTRL_DEF (PCF8591_ADC0 | PCF8591_4S | PCF8591_AOUT)
+
+
+/** Create a PCF8591 object connected to the specified I2C bus and deviceAddress
+ *
+*/
+class PCF8591 {
+public:
+  /** Create a PCF8591 AD and DA object using a specified I2C bus and slaveaddress
+   *
+   * @param I2C &i2c the I2C port to connect to 
+   * @param char deviceAddress the address of the PCF8591
+  */  
+  PCF8591(I2C *i2c, uint8_t deviceAddress = PCF8591_SA0);
+  
+#if(0)
+//These methods are disabled since they interfere with normal expected behaviour for mbed type Analog I/O
+//
+  /** Set ADC mode
+   *
+   * @param adc_mode      ADC Channel mode, valid Range (PCF8591_4S, PCF8591_3D, PCF8591_2S_1D, PCF8591_2D)
+  */  
+  void setADCMode(uint8_t mode);
+
+  /** Set DAC mode
+   *
+   * @param dac_mode      DAC Channel mode, valid Range (false=disable, true=enable)
+  */  
+  void setDACMode(bool mode);
+#endif
+
+/** Write Analog Output
+  *
+  * @param  analogOut  output value (0..255)
+  */  
+  void write(uint8_t analogOut);        
+
+/** Read Analog Channel 
+  *
+  * @param Channel   ADC channel, valid range PCF8591_ADC0, PCF8591_ADC1, PCF8591_ADC2 or PCF8591_ADC3
+  * @return value    uint8_t AD converted value (0..255, representing 0V..Vcc)   
+  */  
+  uint8_t read(uint8_t channel);
+
+
+  
+protected:
+  I2C *_i2c;                    //I2C bus reference
+  uint8_t _slaveAddress;        //I2C Slave address of device
+  uint8_t _mode;                //Device mode  
+
+/** Initialise AD and DA driver 
+  *
+  */  
+  void _init(); 
+};
+
+
+/** Create a PCF8591 AnalogOut object connected to the specified I2C bus and deviceAddress
+ *
+*/
+class PCF8591_AnalogOut {
+public:
+  /** Create a PCF8591 Analogout object using a specified I2C bus and slaveaddress
+   *
+   * @param I2C &i2c the I2C port to connect to 
+   * @param char deviceAddress the address of the PCF8591
+  */  
+  PCF8591_AnalogOut(I2C *i2c, uint8_t deviceAddress = PCF8591_SA0);
+
+  void write(float value);
+  #ifdef MBED_OPERATORS
+  /** An operator shorthand for write()
+   */ 
+  PCF8591_AnalogOut& operator= (float value);
+  #endif
+
+protected:
+  I2C *_i2c;                    //I2C bus reference
+  uint8_t _slaveAddress;        //I2C Slave address of device
+  uint8_t _mode;                //Device mode  
+
+/** Initialise DAC driver 
+  *
+  */  
+  void _init(); 
+};
+
+
+/** Create a PCF8591 AnalogIn object connected to the specified I2C bus and deviceAddress
+ *
+*/
+class PCF8591_AnalogIn {
+public:
+  /** Create a PCF8591 AnalogIn object using a specified I2C bus and slaveaddress
+   *
+   * @param I2C &i2c the I2C port to connect to 
+   * @param channel ADC channel of the PCF8591   
+   * @param char deviceAddress the address of the PCF8591
+  */  
+  PCF8591_AnalogIn(I2C *i2c, uint8_t channel, uint8_t deviceAddress = PCF8591_SA0);
+
+  float read();
+  #ifdef MBED_OPERATORS
+  /** An operator shorthand for read()
+   */ 
+  operator float();
+  #endif
+
+protected:
+  I2C *_i2c;                    //I2C bus reference
+  uint8_t _slaveAddress;        //I2C Slave address of device
+  uint8_t _mode;                //Device mode  
+  uint8_t _channel;             //Channel    
+
+/** Initialise DAC driver 
+  *
+  */  
+  void _init(); 
+};
+
+
+#endif
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