Marlin_Firmware/Marlin/digipot_mcp4018.cpp

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2017-01-08 10:01:07 -06:00
/**
* 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) && ENABLED(DIGIPOT_MCP4018)
#include "Stream.h"
#include "utility/twi.h"
#include <SlowSoftI2CMaster.h> //https://github.com/stawel/SlowSoftI2CMaster
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// Settings for the I2C based DIGIPOT (MCP4018) based on WT150
#define DIGIPOT_I2C_ADDRESS 0x2f
#define DIGIPOT_A4988_Rsx 0.250
#define DIGIPOT_A4988_Vrefmax 5.0
#define DIGIPOT_A4988_MAX_VALUE 127
#define DIGIPOT_A4988_Itripmax(Vref) ((Vref)/(8.0*DIGIPOT_A4988_Rsx))
#define DIGIPOT_A4988_FACTOR (DIGIPOT_A4988_MAX_VALUE/DIGIPOT_A4988_Itripmax(DIGIPOT_A4988_Vrefmax))
//TODO: MAX_CURRENT -0.5A ?? (currently set to 2A, max possible current 2.5A)
#define DIGIPOT_A4988_MAX_CURRENT (DIGIPOT_A4988_Itripmax(DIGIPOT_A4988_Vrefmax) - 0.5)
static byte current_to_wiper(float current) {
return byte(ceil(float((DIGIPOT_A4988_FACTOR * current))));
}
static uint8_t sda_pins[DIGIPOT_I2C_NUM_CHANNELS] = {
DIGIPOTS_I2C_SDA_X,
DIGIPOTS_I2C_SDA_Y,
DIGIPOTS_I2C_SDA_Z,
DIGIPOTS_I2C_SDA_E0,
DIGIPOTS_I2C_SDA_E1,
};
static SlowSoftI2CMaster pots[DIGIPOT_I2C_NUM_CHANNELS] = {
SlowSoftI2CMaster { sda_pins[0], DIGIPOTS_I2C_SCL },
SlowSoftI2CMaster { sda_pins[1], DIGIPOTS_I2C_SCL },
SlowSoftI2CMaster { sda_pins[2], DIGIPOTS_I2C_SCL },
SlowSoftI2CMaster { sda_pins[3], DIGIPOTS_I2C_SCL },
SlowSoftI2CMaster { sda_pins[4], DIGIPOTS_I2C_SCL }
};
static void i2c_send(int channel, byte v) {
if (WITHIN(channel, 0, DIGIPOT_I2C_NUM_CHANNELS - 1)) {
pots[channel].i2c_start(((DIGIPOT_I2C_ADDRESS) << 1) | I2C_WRITE);
pots[channel].i2c_write(v);
pots[channel].i2c_stop();
}
}
// This is for the MCP4018 I2C based digipot
void digipot_i2c_set_current(int channel, float current) {
current = min(max(current, 0.0f), float(DIGIPOT_A4988_MAX_CURRENT));
i2c_send(channel, current_to_wiper(current));
}
void digipot_i2c_init() {
const float digipot_motor_current[] = DIGIPOT_I2C_MOTOR_CURRENTS;
for (uint8_t i = 0; i < DIGIPOT_I2C_NUM_CHANNELS; i++)
pots[i].i2c_init();
// 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, digipot_motor_current[i]);
}
#endif // DIGIPOT_I2C && DIGIPOT_MCP4018