Digipot.h

00001 #ifndef DIGIPOT_H
00002 #define DIGIPOT_H
00003 
00004 #include "libs/Kernel.h"
00005 #include "I2C.h" // mbed.h lib
00006 #include "libs/utils.h"
00007 #include <string>
00008 #include <math.h>
00009 
00010 class Digipot{
00011     public:
00012         Digipot(){ }
00013       
00014         char current_to_wiper( double current ){
00015             return char(ceil(double((113.33*current)))); 
00016         }
00017 
00018         void i2c_send( char first, char second, char third ){
00019             this->i2c->start();
00020             this->i2c->write(first);
00021             this->i2c->write(second);
00022             this->i2c->write(third);
00023             this->i2c->stop(); 
00024         }
00025 
00026         void set_current( int channel, double current ){ 
00027 
00028             current = min( max( current, 0.0L ), 2.0L );
00029 
00030             // I2C com 
00031             this->i2c = new mbed::I2C(p9, p10); 
00032            
00033             // Initial setup 
00034             this->i2c_send( 0x58, 0x40, 0xff );   
00035             this->i2c_send( 0x58, 0xA0, 0xff );   
00036 
00037             // Set actual wiper value
00038             char adresses[4] = { 0x00, 0x10, 0x60, 0x70 };  
00039             this->i2c_send( 0x58, adresses[channel], this->current_to_wiper(current) );   
00040 
00041         } 
00042 
00043         mbed::I2C* i2c;
00044 };
00045 
00046 
00047 #endif