Diff: PCF8591.cpp

Revision:

0:1116b0d151fc

--- /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);  
+};