55 lines
1.5 KiB
C++
55 lines
1.5 KiB
C++
#include "Configuration.h"
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#ifdef DIGIPOT_I2C
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#include "Stream.h"
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#include "utility/twi.h"
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#include "Wire.h"
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// Settings for the I2C based DIGIPOT (MCP4451) on Azteeg X3 Pro
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#define DIGIPOT_I2C_FACTOR 106.7
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#define DIGIPOT_I2C_MAX_CURRENT 2.5
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static byte current_to_wiper( float current ){
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return byte(ceil(float((DIGIPOT_I2C_FACTOR*current))));
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}
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static void i2c_send(byte addr, byte a, byte b)
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{
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Wire.beginTransmission(addr);
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Wire.write(a);
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Wire.write(b);
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Wire.endTransmission();
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}
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// This is for the MCP4451 I2C based digipot
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void digipot_i2c_set_current( int channel, float current )
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{
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current = min( (float) max( current, 0.0f ), DIGIPOT_I2C_MAX_CURRENT);
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// these addresses are specific to Azteeg X3 Pro, can be set to others,
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// In this case first digipot is at address A0=0, A1= 0, second one is at A0=0, A1= 1
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byte addr= 0x2C; // channel 0-3
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if(channel >= 4) {
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addr= 0x2E; // channel 4-7
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channel-= 4;
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}
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// Initial setup
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i2c_send( addr, 0x40, 0xff );
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i2c_send( addr, 0xA0, 0xff );
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// Set actual wiper value
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byte addresses[4] = { 0x00, 0x10, 0x60, 0x70 };
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i2c_send( addr, addresses[channel], current_to_wiper(current) );
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}
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void digipot_i2c_init()
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{
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const float digipot_motor_current[] = DIGIPOT_I2C_MOTOR_CURRENTS;
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Wire.begin();
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// setup initial currents as defined in Configuration_adv.h
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for(int i=0;i<=sizeof(digipot_motor_current)/sizeof(float);i++) {
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digipot_i2c_set_current(i, digipot_motor_current[i]);
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}
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}
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#endif
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