MCP23008.cpp

00001 #include "mbed.h"
00002 #include "MCP23008.h"
00003 #include "MODSERIAL.h"
00004 
00005 
00006 namespace {
00007     const uint8_t I2C_WRITE         = 0x00;
00008     const uint8_t I2C_READ          = 0x01;
00009 
00010     /* MCP23008 registers */
00011     const uint8_t IODIR             = 0x00;
00012     const uint8_t GPIO              = 0x09;
00013     const uint8_t PULLUP            = 0x06;
00014     
00015     //Channel addresses
00016     const uint8_t CHNL_0     = 0x01;
00017     const uint8_t CHNL_1     = 0x02;
00018     const uint8_t CHNL_2     = 0x04;
00019     const uint8_t CHNL_3     = 0x08;
00020 };
00021 
00022 MCP23008::MCP23008 (PinName sda, PinName scl, uint8_t address, int freq): i2c( sda, scl ){
00023     addrI2C = address;
00024     i2c.frequency(freq);
00025 }
00026 
00027 void MCP23008::setAddress(int address){
00028     addrI2C = address;
00029 }
00030 
00031 void MCP23008::writeOutput(int chn1, int chn2, int chn3, int chn4){
00032     char data[2];
00033     char data2[2];
00034     uint8_t val = 0x00;
00035     
00036     //Create mask for all bits that should be on
00037     if(chn1) val = val | CHNL_0;
00038     if(chn2) val = val | CHNL_1;
00039     if(chn3) val = val | CHNL_2;
00040     if(chn4) val = val | CHNL_3;
00041         
00042     data[0] = GPIO;  //register address
00043     data[1] = val;   //GPIO bit map
00044     data2[0] = PULLUP;
00045     data2[1] = 0x00;
00046 
00047     i2c.write((addrI2C<<1)|(I2C_WRITE), data, 2);
00048     i2c.write((addrI2C<<1)|(I2C_WRITE), data2, 2);
00049     //wait(0.1);
00050 }
00051 
00052 void MCP23008::init(){
00053     char io_setup[2];
00054     
00055     io_setup[0] = IODIR;
00056     io_setup[1] = 0x00; //turn all pins to outputs
00057     
00058     i2c.write((addrI2C<<1)|(I2C_WRITE), io_setup, 2);
00059     //wait(0.1);
00060     
00061     //Set all outputs to off
00062     GPIO_Pin_Status = 0x00;
00063 }