297 lines
7.4 KiB
C++
297 lines
7.4 KiB
C++
#include "MCP4461.h"
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/*
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Library to control the MCP4461 Digital Potentiometer over I2C.
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http://ww1.microchip.com/downloads/en/DeviceDoc/22265a.pdf
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This library does not fully implement the functionality of
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the MCP4461 – just the basics of changing the wiper values.
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Note this is currently configured to use the second I2C bus
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on the Due: Wire1
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The master joins the bus with the default address of 0
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No warranty given or implied, use at your own risk.
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Tony@think3dprint3d.com
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GPL v3
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*/
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#include <stdio.h>
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#include <Wire.h>
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//constructors just set the address
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MCP4461::MCP4461() {
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_mcp4461_address = DEFAULT_ADDRESS;
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}
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MCP4461::MCP4461(uint8_t mcp4461_addr) {
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_mcp4461_address = mcp4461_addr;
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}
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void MCP4461::begin() {
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Wire1.begin();
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}
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void MCP4461::setVolatileWiper(uint8_t wiper, uint16_t wiper_value){
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uint16_t value = wiper_value;
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if (value > 0xFF) value = 0x100;
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uint8_t d_byte = (uint8_t)value;
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uint8_t c_byte;
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if (value > 0xFF)c_byte = 0x1; //the 8th data bit is 1
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else c_byte =0;
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switch (wiper) {
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case 0:
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c_byte |= MCP4461_VW0;
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break;
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case 1:
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c_byte |= MCP4461_VW1;
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break;
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case 2:
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c_byte |= MCP4461_VW2;
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break;
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case 3:
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c_byte |= MCP4461_VW3;
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break;
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default:
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break; //not a valid wiper
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}
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c_byte |= MCP4461_WRITE;
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//send command byte
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Wire1.beginTransmission(_mcp4461_address);
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Wire1.write(c_byte);
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Wire1.write(d_byte);
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Wire1.endTransmission(); //do not release bus
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}
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void MCP4461::setNonVolatileWiper(uint8_t wiper, uint16_t wiper_value){
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uint16_t value = wiper_value;
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if (value > 0xFF) value = 0x100;
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uint8_t d_byte = (uint8_t)value;
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uint8_t c_byte;
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if (value > 0xFF)c_byte = 0x1; //the 8th data bit is 1
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else c_byte =0;
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switch (wiper) {
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case 0:
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c_byte |= MCP4461_NVW0;
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break;
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case 1:
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c_byte |= MCP4461_NVW1;
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break;
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case 2:
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c_byte |= MCP4461_NVW2;
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break;
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case 3:
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c_byte |= MCP4461_NVW3;
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break;
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default:
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break; //not a valid wiper
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}
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c_byte |= MCP4461_WRITE;
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//send command byte
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Wire1.beginTransmission(_mcp4461_address);
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Wire1.write(c_byte);
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Wire1.write(d_byte);
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Wire1.endTransmission(); //do not release bus
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delay(20); //allow the write to complete (this is wasteful - better to check if the write has completed)
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}
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//set all the wipers in one transmission, more verbose but quicker than multiple calls to
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//setVolatileWiper(uint8_t wiper, uint16_t wiper_value)
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void MCP4461::setVolatileWipers(uint16_t wiper_value){
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uint16_t value = wiper_value;
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if (value > 0xFF) value = 0x100;
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uint8_t d_byte = (uint8_t)value;
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uint8_t c_byte;
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if (value > 0xFF)c_byte = 0x1; //the 8th data bit is 1
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else c_byte =0;
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Wire1.beginTransmission(_mcp4461_address);
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c_byte |= MCP4461_WRITE;
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c_byte |= MCP4461_VW0;
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Wire1.write(c_byte);
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Wire1.write(d_byte);
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if (value > 0xFF) c_byte = 0x1;
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else c_byte =0;
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c_byte |= MCP4461_WRITE;
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c_byte |= MCP4461_VW1;
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Wire1.write(c_byte);
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Wire1.write(d_byte);
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if (value > 0xFF) c_byte = 0x1;
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else c_byte =0;
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c_byte |= MCP4461_WRITE;
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c_byte |= MCP4461_VW2;
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Wire1.write(c_byte);
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Wire1.write(d_byte);
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if (value > 0xFF) c_byte = 0x1;
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else c_byte =0;
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c_byte |= MCP4461_WRITE;
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c_byte |= MCP4461_VW3;
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Wire1.write(c_byte);
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Wire1.write(d_byte);
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Wire1.endTransmission();
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}
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//set all the wipers in one transmission, more verbose but quicker than multiple calls to
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//setNonVolatileWiper(uint8_t wiper, uint16_t wiper_value)
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void MCP4461::setNonVolatileWipers(uint16_t wiper_value){
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uint16_t value = wiper_value;
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if (value > 0xFF) value = 0x100;
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uint8_t d_byte = (uint8_t)value;
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uint8_t c_byte;
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if (value > 0xFF)c_byte = 0x1; //the 8th data bit is 1
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else c_byte =0;
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Wire1.beginTransmission(_mcp4461_address);
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c_byte |= MCP4461_WRITE;
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c_byte |= MCP4461_NVW0;
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Wire1.write(c_byte);
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Wire1.write(d_byte);
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delay(20); //allow the write to complete (this is wasteful - better to check if the write has completed)
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if (value > 0xFF) c_byte = 0x1;
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else c_byte =0;
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c_byte |= MCP4461_WRITE;
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c_byte |= MCP4461_NVW1;
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Wire1.write(c_byte);
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Wire1.write(d_byte);
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delay(20);
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if (value > 0xFF) c_byte = 0x1;
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else c_byte =0;
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c_byte |= MCP4461_WRITE;
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c_byte |= MCP4461_NVW2;
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Wire1.write(c_byte);
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Wire1.write(d_byte);
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delay(20);
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if (value > 0xFF) c_byte = 0x1;
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else c_byte =0;
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c_byte |= MCP4461_WRITE;
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c_byte |= MCP4461_NVW3;
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Wire1.write(c_byte);
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Wire1.write(d_byte);
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Wire1.endTransmission();
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delay(20);
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}
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//return the value for a specific wiper
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uint16_t MCP4461::getNonVolatileWiper(uint8_t wiper){
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uint16_t ret = 0;
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uint16_t c_byte =0;
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switch (wiper) {
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case 0:
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c_byte |= MCP4461_NVW0;
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break;
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case 1:
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c_byte |= MCP4461_NVW1;
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break;
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case 2:
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c_byte |= MCP4461_NVW2;
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break;
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case 3:
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c_byte |= MCP4461_NVW3;
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break;
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default:
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return 0; //not a valid wiper
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}
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c_byte |= MCP4461_READ;
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//send command byte
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Wire1.beginTransmission(_mcp4461_address);
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Wire1.write(c_byte);
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Wire1.endTransmission(false); //do not release bus
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Wire1.requestFrom((uint8_t)_mcp4461_address,(uint8_t)2);
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//read the register
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int i = 0;
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while(Wire1.available())
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{
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ret |= Wire1.read();
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if (i==0) ret = ret<<8;
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i++;
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}
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return ret;
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}
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//return the volatile value for a specific wiper
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uint16_t MCP4461::getVolatileWiper(uint8_t wiper){
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uint16_t ret = 0;
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uint16_t c_byte =0;
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switch (wiper) {
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case 0:
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c_byte |= MCP4461_VW0;
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break;
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case 1:
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c_byte |= MCP4461_VW1;
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break;
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case 2:
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c_byte |= MCP4461_VW2;
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break;
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case 3:
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c_byte |= MCP4461_VW3;
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break;
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default:
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return 0; //not a valid wiper
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}
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c_byte |= MCP4461_READ;
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//send command byte
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Wire1.beginTransmission(_mcp4461_address);
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Wire1.write(c_byte);
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Wire1.endTransmission(false); //do not release bus
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Wire1.requestFrom((uint8_t)_mcp4461_address,(uint8_t)2);
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//read the register
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int i = 0;
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while(Wire1.available())
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{
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ret |= Wire1.read();
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if (i==0) ret = ret<<8;
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i++;
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}
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return ret;
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}
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//return the status register
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uint16_t MCP4461::getStatus(){
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uint16_t ret = 0;
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uint16_t c_byte =0;
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c_byte |= MCP4461_STATUS;
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c_byte |= MCP4461_READ;
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//send command byte
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Wire1.beginTransmission(_mcp4461_address);
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Wire1.write(c_byte);
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Wire1.endTransmission(false); //do not release bus
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Wire1.requestFrom((uint8_t)_mcp4461_address, (uint8_t)2);
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//read the register
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int i = 0;
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while(Wire1.available())
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{
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ret |= Wire1.read();
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if (i==0) ret = ret<<8;
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i++;
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}
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return ret;
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}
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//toggle a specific pot channel on and off
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/* //NOT YET IMPLEMENTED
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void MCP4461::toggleWiper(uint8_t wiper){
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uint16_t tcon = 0;
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uint16_t c_byte =0;
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//read the specific TCONX register to get the current stae of the
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//pot connections
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if (wiper <=1) {
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c_byte |= MCP4461_TCON0;
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c_byte |= MCP4461_READ;
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}
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else {
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c_byte |= MCP4461_TCON1;
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c_byte |= MCP4461_READ;
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}
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//send command byte
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Wire1.beginTransmission(_mcp4461_address);
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Wire1.write(c_byte);
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Wire1.endTransmission(false); //do not release bus
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Wire1.requestFrom((uint8_t)_mcp4461_address,(uint8_t)2);
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//read the register
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int i = 0;
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while(Wire1.available())
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{
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tcon |= Wire1.read();
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if (i==0) tcon = tcon<<8;
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i++;
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}
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SerialUSB.print(" TCON ");
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SerialUSB.print(tcon,BIN);
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} */
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