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MarlinFirmware/Marlin/digipot_mcp4451.cpp
2017-06-07 16:07:38 -05:00

80 lines
2.5 KiB
C++

/**
* Marlin 3D Printer Firmware
* Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "MarlinConfig.h"
#if ENABLED(DIGIPOT_I2C) && DISABLED(DIGIPOT_MCP4018)
#include "Stream.h"
#include "utility/twi.h"
#include "Wire.h"
// Settings for the I2C based DIGIPOT (MCP4451) on Azteeg X3 Pro
#if MB(5DPRINT)
#define DIGIPOT_I2C_FACTOR 117.96
#define DIGIPOT_I2C_MAX_CURRENT 1.736
#else
#define DIGIPOT_I2C_FACTOR 106.7
#define DIGIPOT_I2C_MAX_CURRENT 2.5
#endif
static byte current_to_wiper(const float current) {
return byte(ceil(float((DIGIPOT_I2C_FACTOR * current))));
}
static void i2c_send(const byte addr, const byte a, const byte b) {
Wire.beginTransmission(addr);
Wire.write(a);
Wire.write(b);
Wire.endTransmission();
}
// This is for the MCP4451 I2C based digipot
void digipot_i2c_set_current(uint8_t channel, float current) {
current = min((float) max(current, 0.0f), DIGIPOT_I2C_MAX_CURRENT);
// these addresses are specific to Azteeg X3 Pro, can be set to others,
// In this case first digipot is at address A0=0, A1= 0, second one is at A0=0, A1= 1
byte addr = 0x2C; // channel 0-3
if (channel >= 4) {
addr = 0x2E; // channel 4-7
channel -= 4;
}
// Initial setup
i2c_send(addr, 0x40, 0xFF);
i2c_send(addr, 0xA0, 0xFF);
// Set actual wiper value
byte addresses[4] = { 0x00, 0x10, 0x60, 0x70 };
i2c_send(addr, addresses[channel], current_to_wiper(current));
}
void digipot_i2c_init() {
static const float digipot_motor_current[] PROGMEM = DIGIPOT_I2C_MOTOR_CURRENTS;
Wire.begin();
// setup initial currents as defined in Configuration_adv.h
for (uint8_t i = 0; i < COUNT(digipot_motor_current); i++)
digipot_i2c_set_current(i, pgm_read_float(&digipot_motor_current[i]));
}
#endif // DIGIPOT_I2C