PCF8591.h

00001 /* PCF8591 - I2C 8 bit, 4 channel A/D and 8 bit, 1 channel D/A converter
00002  * Copyright (c) 2013 Wim Huiskamp
00003  *
00004  * Released under the MIT License: http://mbed.org/license/mit
00005  *
00006  * version 0.2 Initial Release
00007 */
00008 #ifndef _PCF8591_H
00009 #define _PCF8591_H
00010 
00011 /** Driver for PCF8591 I2C I2C A/D and D/A converter
00012  *
00013  * @code
00014  * #include "mbed.h"
00015  * #include "PCF8591.h"
00016  * 
00017  * // I2C Communication
00018  * I2C i2c_adcdac(p28,p27); // SDA, SCL for LPC1768
00019  * //I2C i2c_adcdac(P0_10,P0_11); // SDA, SCL for LPC812
00020  *
00021  * //Declare a composite ADC and DAC device that may be used through public methods
00022  * PCF8591 adc_dac(&i2c_adcdac); // I2C bus, Default PCF8591 Slaveaddress
00023  *
00024  * //Declare independent ADC and DAC objects that may be used similar to mbed AnalogIn and AnalogOut pins
00025  * //PCF8591_AnalogOut anaOut(&i2c_bus);
00026  * //
00027  * //PCF8591_AnalogIn anaIn(&i2c_bus, PCF8591_ADC0);
00028  *
00029  * 
00030  * int main() {
00031  *   uint8_t count = 0; 
00032  *   uint8_t analog;  
00033  *
00034  *   while(1) {
00035  *     wait(0.2);    
00036  *     count++;       
00037  *
00038  *     // Composite device methods    
00039  *     adc_dac.write(count);                 // write D/A value
00040  *     analog = adc_dac.read(PCF8591_ADC0);  // read A/D value for Channel 0
00041  * 
00042  *     // mbed pin type methods    
00043  *     //anaOut = (float)count / 255.0;        // write D/A value using range 0.0f .. 1.0f
00044  *     //analog = anaIn * 33.0;                // read A/D value for Channel 0 in (Volts*10)
00045  *   }
00046  *  
00047  * }
00048  * @endcode
00049  */
00050 
00051 
00052 //Address Defines for PCF8591
00053 #define PCF8591_SA0 0x90
00054 #define PCF8591_SA1 0x92
00055 #define PCF8591_SA2 0x94
00056 #define PCF8591_SA3 0x96
00057 #define PCF8591_SA4 0x98
00058 #define PCF8591_SA5 0x9A
00059 #define PCF8591_SA6 0x9C
00060 #define PCF8591_SA7 0x9E
00061 
00062 //Register Defines for PCF8591
00063 #define PCF8591_CTRL 0x00
00064 #define PCF8591_ADR0 0x01
00065 #define PCF8591_ADR1 0x02
00066 #define PCF8591_ADR2 0x03
00067 #define PCF8591_ADR3 0x04
00068 #define PCF8591_DAR  0x01
00069 
00070 //Control Register Defines for PCF8591
00071 //AD Channels
00072 #define PCF8591_ADC0 0x00
00073 #define PCF8591_ADC1 0x01
00074 #define PCF8591_ADC2 0x02
00075 #define PCF8591_ADC3 0x03
00076 //AD Channel Mask
00077 #define PCF8591_CHMSK   0x03
00078 
00079 //Auto Increment flag (0=disable, 1=enable)
00080 #define PCF8591_AIF  0x04
00081 
00082 //AD Channels Input modes
00083 //4 Single Channels (Chan0=AIN0, Chan1=AIN0, Chan2=AIN0, Chan3=AIN0)
00084 #define PCF8591_4S   0x00
00085 //3 Diff Channels (Chan0=AIN0-AIN3, Chan1=AIN1-AIN3, Chan2=AIN2-AIN3)
00086 #define PCF8591_3D   0x10
00087 //2 Single Channels (Chan0=AIN0, Chan1=AIN1)
00088 //1 Diff Channel    (Chan2=AIN2-AIN3)
00089 #define PCF8591_2S_1D 0x20
00090 //2 Diff Channels (Chan0=AIN0-AIN1, Chan1=AIN2-AIN3)
00091 #define PCF8591_2D   0x30
00092 //ChannelMode Mask
00093 #define PCF8591_CHMDMSK  0x30
00094 
00095 //Analog Output enable flag (0=disable, 1=enable)
00096 #define PCF8591_AOUT 0x40
00097 
00098 //Default Mode: ADC0, AutoIncr Off, 4 Single Chan, AnalogOut On
00099 #define PCF8591_CTRL_DEF (PCF8591_ADC0 | PCF8591_4S | PCF8591_AOUT)
00100 
00101 
00102 /** Create a PCF8591 object connected to the specified I2C bus and deviceAddress
00103  *
00104 */
00105 class PCF8591 {
00106 public:
00107   /** Create a PCF8591 AD and DA object using a specified I2C bus and slaveaddress
00108    *
00109    * @param I2C &i2c the I2C port to connect to 
00110    * @param char deviceAddress the address of the PCF8591
00111   */  
00112   PCF8591(I2C *i2c, uint8_t deviceAddress = PCF8591_SA0);
00113   
00114 #if(0)
00115 //These methods are disabled since they interfere with normal expected behaviour for mbed type Analog I/O
00116 //
00117   /** Set ADC mode
00118    *
00119    * @param adc_mode      ADC Channel mode, valid Range (PCF8591_4S, PCF8591_3D, PCF8591_2S_1D, PCF8591_2D)
00120   */  
00121   void setADCMode(uint8_t mode);
00122 
00123   /** Set DAC mode
00124    *
00125    * @param dac_mode      DAC Channel mode, valid Range (false=disable, true=enable)
00126   */  
00127   void setDACMode(bool mode);
00128 #endif
00129 
00130 /** Write Analog Output
00131   *
00132   * @param  analogOut  output value (0..255)
00133   */  
00134   void write(uint8_t analogOut);        
00135 
00136 /** Read Analog Channel 
00137   *
00138   * @param Channel   ADC channel, valid range PCF8591_ADC0, PCF8591_ADC1, PCF8591_ADC2 or PCF8591_ADC3
00139   * @return value    uint8_t AD converted value (0..255, representing 0V..Vcc)   
00140   */  
00141   uint8_t read(uint8_t channel);
00142 
00143 
00144   
00145 protected:
00146   I2C *_i2c;                    //I2C bus reference
00147   uint8_t _slaveAddress;        //I2C Slave address of device
00148   uint8_t _mode;                //Device mode  
00149 
00150 /** Initialise AD and DA driver 
00151   *
00152   */  
00153   void _init(); 
00154 };
00155 
00156 
00157 /** Create a PCF8591 AnalogOut object connected to the specified I2C bus and deviceAddress
00158  *
00159 */
00160 class PCF8591_AnalogOut {
00161 public:
00162   /** Create a PCF8591 Analogout object using a specified I2C bus and slaveaddress
00163    *
00164    * @param I2C &i2c the I2C port to connect to 
00165    * @param char deviceAddress the address of the PCF8591
00166   */  
00167   PCF8591_AnalogOut(I2C *i2c, uint8_t deviceAddress = PCF8591_SA0);
00168 
00169   void write(float value);
00170   #ifdef MBED_OPERATORS
00171   /** An operator shorthand for write()
00172    */ 
00173   PCF8591_AnalogOut& operator= (float value);
00174   #endif
00175 
00176 protected:
00177   I2C *_i2c;                    //I2C bus reference
00178   uint8_t _slaveAddress;        //I2C Slave address of device
00179   uint8_t _mode;                //Device mode  
00180 
00181 /** Initialise DAC driver 
00182   *
00183   */  
00184   void _init(); 
00185 };
00186 
00187 
00188 /** Create a PCF8591 AnalogIn object connected to the specified I2C bus and deviceAddress
00189  *
00190 */
00191 class PCF8591_AnalogIn {
00192 public:
00193   /** Create a PCF8591 AnalogIn object using a specified I2C bus and slaveaddress
00194    *
00195    * @param I2C &i2c the I2C port to connect to 
00196    * @param channel ADC channel of the PCF8591   
00197    * @param char deviceAddress the address of the PCF8591
00198   */  
00199   PCF8591_AnalogIn(I2C *i2c, uint8_t channel, uint8_t deviceAddress = PCF8591_SA0);
00200 
00201   float read();
00202   #ifdef MBED_OPERATORS
00203   /** An operator shorthand for read()
00204    */ 
00205   operator float();
00206   #endif
00207 
00208 protected:
00209   I2C *_i2c;                    //I2C bus reference
00210   uint8_t _slaveAddress;        //I2C Slave address of device
00211   uint8_t _mode;                //Device mode  
00212   uint8_t _channel;             //Channel    
00213 
00214 /** Initialise DAC driver 
00215   *
00216   */  
00217   void _init(); 
00218 };
00219 
00220 
00221 #endif