PCF8591.h

00001 #ifndef PCF8591_H
00002 #define PCF8591_H
00003 
00004 /**
00005  * Interface to the PCF8591 chip (http://www.nxp.com/documents/data_sheet/PCF8591.pdf)
00006  * which has four 8-bit analog inputs and one 8-bit analog output.
00007  *
00008  * @code
00009  * #include "mbed.h"
00010  *
00011  * PCF8591 adc;
00012  *
00013  * int main(void) {
00014  *
00015  *    while(1) {
00016  *       // read analog value
00017  *       int val = adc.read(PCF8591::A0);
00018  *
00019  *       // do something with value...
00020  *    }
00021  * }
00022  * @endcode
00023  */
00024 class PCF8591 {
00025 public:
00026 
00027     enum AnalogIn {
00028         A0,
00029         A1,
00030         A2,
00031         A3
00032     };
00033 
00034     
00035     /** Create an interface to the PCF8591 chip
00036      *
00037      *
00038      *  @param sda the I2C SDA pin
00039      *  @param scl the I2C SCL pin
00040      *  @param i2cAddr the upper 7 bits of the chip's address
00041      */
00042     PCF8591(PinName sda = P0_10, PinName scl = P0_11, int i2cAddr = 0x9E);
00043     
00044     /** Reads one value for the specified analog port
00045      *
00046      *  @param port the analog in to read (A0..A3)
00047      *
00048      *  @returns
00049      *       the value on success (0..255)
00050      *       -1 on failure
00051      */
00052     int read(AnalogIn port);
00053 
00054 private:
00055     I2C m_i2c;
00056     int m_addr;
00057 };
00058 
00059 #endif
00060