100 lines
3.0 KiB
C
100 lines
3.0 KiB
C
|
|
||
|
|
// MCP4251 2-channel Digital Potentiometer
|
||
|
|
// ww1.microchip.com/downloads/en/DeviceDoc/22059b.pdf
|
||
|
|
|
||
|
|
#include <Arduino.h>
|
||
|
|
#include <spi4teensy3.h>
|
||
|
|
|
||
|
|
#ifndef Mcp4251_h
|
||
|
|
#define Mcp4251_h
|
||
|
|
|
||
|
|
class MCP4251
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
// You must at least specify the slave select pin and the rated resistance
|
||
|
|
MCP4251(uint8_t slave_select, float rAB_ohms);
|
||
|
|
|
||
|
|
// If you have measured wiper resistance, rW
|
||
|
|
MCP4251(uint8_t slave_select, float rAB_ohms, float rW_ohms);
|
||
|
|
|
||
|
|
// The resistance scaling, defaults to rAB_ohms
|
||
|
|
float scale;
|
||
|
|
|
||
|
|
// Read potentiometer values
|
||
|
|
float wiper0();
|
||
|
|
float wiper1();
|
||
|
|
unsigned int wiper0_pos();
|
||
|
|
unsigned int wiper1_pos();
|
||
|
|
|
||
|
|
// Write potentiometer values
|
||
|
|
void wiper0(float ohms);
|
||
|
|
void wiper1(float ohms);
|
||
|
|
|
||
|
|
void wiper0_pos(unsigned int wiper_pos);
|
||
|
|
void wiper1_pos(unsigned int wiper_pos);
|
||
|
|
|
||
|
|
// // Not implemented
|
||
|
|
// // Connect / disconnect potentiometers
|
||
|
|
// bool pot0_connected(bool terminal_a, bool wiper, bool terminal_b);
|
||
|
|
// bool pot1_connected(bool terminal_a, bool wiper, bool terminal_b);
|
||
|
|
// void pot0_connect(bool terminal_a, bool wiper, bool terminal_b);
|
||
|
|
// void pot1_connect(bool terminal_a, bool wiper, bool terminal_b);
|
||
|
|
//
|
||
|
|
// bool pot0_shutdown();
|
||
|
|
// bool pot1_shutdown();
|
||
|
|
// void pot0_shutdown(bool shutdown);
|
||
|
|
// void pot1_shutdown(bool shutdown);
|
||
|
|
//
|
||
|
|
// bool hw_shutdown();
|
||
|
|
|
||
|
|
protected:
|
||
|
|
// const static float rW_ohms_typical = 117.50f;
|
||
|
|
const static unsigned int resolution_7bit = 128;
|
||
|
|
const static unsigned int resolution_8bit = 256;
|
||
|
|
|
||
|
|
// Other devices can be configured below vv as per the device numbering scheme:
|
||
|
|
// MCP4N-- N=1 single pot, N=2 dual pot
|
||
|
|
// MCP4--N N=1 potentiometer, N=2 rheostat
|
||
|
|
// MCP4-N- N=3 7-bit volatile, N=4 7-bit non-volatile, N=5 8-bit volatile, N=6 8-bit non-volatile
|
||
|
|
const static bool non_volatile = false;
|
||
|
|
const static unsigned int resolution = resolution_8bit;
|
||
|
|
|
||
|
|
float rW_ohms;
|
||
|
|
float rAB_ohms;
|
||
|
|
float rAW_ohms_max;
|
||
|
|
|
||
|
|
uint8_t slave_select_pin;
|
||
|
|
|
||
|
|
const static uint8_t kADR_WIPER0 = B00000000;
|
||
|
|
const static uint8_t kADR_WIPER1 = B00010000;
|
||
|
|
|
||
|
|
const static uint8_t kCMD_READ = B00001100;
|
||
|
|
const static uint8_t kCMD_WRITE = B00000000;
|
||
|
|
|
||
|
|
const static uint8_t kADR_VOLATILE = B00000000;
|
||
|
|
const static uint8_t kADR_NON_VOLATILE = B00100000;
|
||
|
|
|
||
|
|
const static uint8_t kTCON_REGISTER = B01000000;
|
||
|
|
const static uint8_t kSTATUS_REGISTER = B01010000;
|
||
|
|
|
||
|
|
uint16_t byte2uint16(byte high_byte, byte low_byte);
|
||
|
|
byte uint16_high_byte(uint16_t uint16);
|
||
|
|
byte uint16_low_byte(uint16_t uint16);
|
||
|
|
|
||
|
|
void setup_ss(uint8_t slave_select_pin);
|
||
|
|
void setup_resistance(float rAB_ohms, float rW_ohms);
|
||
|
|
|
||
|
|
float step_increment();
|
||
|
|
unsigned int ohms2wiper_pos(float ohms);
|
||
|
|
float wiper_pos2ohms(unsigned int wiper_pos);
|
||
|
|
|
||
|
|
uint16_t read(byte cmd_byte);
|
||
|
|
void write(byte cmd_byte, byte data_byte);
|
||
|
|
void wiper_pos(byte pot, unsigned int wiper_pos);
|
||
|
|
};
|
||
|
|
|
||
|
|
#endif // Mcp4251_h
|
||
|
|
|
||
|
|
|
||
|
|
|