Driver + example for MCP4725 12-bit I2C DAC

This commit is contained in:
UncleRus 2016-11-19 21:25:21 +05:00
parent 6481f71ce0
commit 16b38f94b0
5 changed files with 256 additions and 0 deletions

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PROGRAM = mcp4725_test
EXTRA_COMPONENTS = extras/i2c extras/mcp4725
#ESPBAUD = 460800
include ../../common.mk

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/*
* Example of using MCP4725 DAC
*
* Part of esp-open-rtos
* Copyright (C) 2016 Ruslan V. Uss <unclerus@gmail.com>
* BSD Licensed as described in the file LICENSE
*/
#include <esp/uart.h>
#include <espressif/esp_common.h>
#include <i2c/i2c.h>
#include <mcp4725/mcp4725.h>
#include <stdio.h>
#include <FreeRTOS.h>
#include <task.h>
#define SCL_PIN 5
#define SDA_PIN 4
#define ADDR MCP4725A0_ADDR0
#define VDD 3.3
inline static void wait_for_eeprom()
{
while (mcp4725_eeprom_busy(ADDR))
{
printf("...DAC is busy, waiting...\n");
vTaskDelay(1);
}
}
void user_init(void)
{
uart_set_baud(0, 115200);
printf("SDK version:%s\n", sdk_system_get_sdk_version());
i2c_init(SCL_PIN, SDA_PIN);
// setup EEPROM values
if (mcp4725_get_power_mode(ADDR, true) != MCP4725_PM_NORMAL)
{
printf("DAC was sleeping... Wake up Neo!\n");
mcp4725_set_power_mode(ADDR, MCP4725_PM_NORMAL, true);
wait_for_eeprom();
}
printf("Set default DAC ouptut value to MAX...\n");
mcp4725_set_raw_output(ADDR, MCP4725_MAX_VALUE, true);
wait_for_eeprom();
printf("And now default DAC output value is 0x%03x\n", mcp4725_get_raw_output(ADDR, true));
printf("Now let's generate the sawtooth wave in slow manner\n");
float vout = 0;
while (true)
{
vout += 0.1;
if (vout > VDD) vout = 0;
printf("Vout: %.02f\n", vout);
mcp4725_set_voltage(ADDR, VDD, vout, false);
// It will be very low freq wave
vTaskDelay(100 / portTICK_PERIOD_MS);
}
}

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# Component makefile for extras/mcp4725
# expected anyone using this driver includes it as 'mcp4725/mcp4725.h'
INC_DIRS += $(mcp4725_ROOT)..
# args for passing into compile rule generation
mcp4725_SRC_DIR = $(mcp4725_ROOT)
$(eval $(call component_compile_rules,mcp4725))

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extras/mcp4725/mcp4725.c Normal file
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/*
* Driver for 12-bit DAC MCP4725
*
* Part of esp-open-rtos
* Copyright (C) 2016 Ruslan V. Uss <unclerus@gmail.com>
* BSD Licensed as described in the file LICENSE
*/
#include "mcp4725.h"
#include <i2c/i2c.h>
#define CMD_DAC 0x40
#define CMD_EEPROM 0x60
#define BIT_READY 0x80
static void read_data(uint8_t addr, uint8_t *buf, uint8_t size)
{
i2c_start();
i2c_write(addr << 1 | 1);
while (size--)
*(buf++) = i2c_read(!size);
i2c_stop();
}
bool mcp4725_eeprom_busy(uint8_t addr)
{
uint8_t res;
read_data(addr, &res, 1);
return !(res & BIT_READY);
}
mcp4725_power_mode_t mcp4725_get_power_mode(uint8_t addr, bool eeprom)
{
uint8_t buf[4];
read_data(addr, buf, eeprom ? 4 : 1);
return (eeprom ? buf[3] >> 5 : buf[0] >> 1) & 0x03;
}
void mcp4725_set_power_mode(uint8_t addr, mcp4725_power_mode_t mode, bool eeprom)
{
uint16_t value = mcp4725_get_raw_output(addr, eeprom);
uint8_t data[] = {
(eeprom ? CMD_EEPROM : CMD_DAC) | ((uint8_t)mode << 1),
value >> 4,
value << 4
};
i2c_slave_write(addr, data, 3);
}
uint16_t mcp4725_get_raw_output(uint8_t addr, bool eeprom)
{
uint8_t buf[5];
read_data(addr, buf, eeprom ? 5 : 3);
return eeprom
? ((uint16_t)(buf[3] & 0x0f) << 8) | buf[4]
: ((uint16_t)buf[0] << 4) | (buf[1] >> 4);
}
void mcp4725_set_raw_output(uint8_t addr, uint16_t value, bool eeprom)
{
uint8_t data[] = {
(eeprom ? CMD_EEPROM : CMD_DAC),
value >> 4,
value << 4
};
i2c_slave_write(addr, data, 3);
}

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extras/mcp4725/mcp4725.h Normal file
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/*
* Driver for 12-bit DAC MCP4725
*
* Part of esp-open-rtos
* Copyright (C) 2016 Ruslan V. Uss <unclerus@gmail.com>
* BSD Licensed as described in the file LICENSE
*/
#ifndef _EXTRAS_MCP4725_H_
#define _EXTRAS_MCP4725_H_
#include <stdint.h>
#include <stdbool.h>
#ifdef __cplusplus
extern "C"
{
#endif
#define MCP4725A0_ADDR0 0x60
#define MCP4725A0_ADDR1 0x61
#define MCP4725A1_ADDR0 0x62
#define MCP4725A1_ADDR1 0x63
#define MCP4725A2_ADDR0 0x64
#define MCP4725A2_ADDR1 0x65
#define MCP4725_MAX_VALUE 0x0fff
/**
* Power mode, see datasheet
*/
typedef enum
{
MCP4725_PM_NORMAL = 0, //!< Normal mode
MCP4725_PM_PD_1K, //!< Power down, 1kOhm resistor to ground
MCP4725_PM_PD_100K, //!< Power down, 100kOhm resistor to ground
MCP4725_PM_PD_500K, //!< Power down, 500kOhm resistor to ground
} mcp4725_power_mode_t;
/**
* Get device EEPROM status
* @param addr Device address
* @return true when EEPROM is busy
*/
bool mcp4725_eeprom_busy(uint8_t addr);
/**
* Get power mode
* @param addr Device address
* @param eeprom Read power mode from EEPROM if true
* @return Power mode
*/
mcp4725_power_mode_t mcp4725_get_power_mode(uint8_t addr, bool eeprom);
/**
* Set power mode
* @param addr Device address
* @param mode Power mode
* @param eeprom Store mode to device EEPROM if true
*/
void mcp4725_set_power_mode(uint8_t addr, mcp4725_power_mode_t mode, bool eeprom);
/**
* Get current DAC value
* @param addr Device address
* @param eeprom Read value from device EEPROM if true
* @return Raw output value, 0..4095
*/
uint16_t mcp4725_get_raw_output(uint8_t addr, bool eeprom);
/**
* Set DAC output value
* @param addr Device address
* @param value Raw output value, 0..4095
* @param eeprom Store value to device EEPROM if true
*/
void mcp4725_set_raw_output(uint8_t addr, uint16_t value, bool eeprom);
/**
* Get current DAC output voltage
* @param addr Device address
* @param vdd Device operating voltage, volts
* @param eeprom Read voltage from device EEPROM if true
* @return Current output voltage, volts
*/
inline float mcp4725_get_voltage(uint8_t addr, float vdd, bool eeprom)
{
return vdd / MCP4725_MAX_VALUE * mcp4725_get_raw_output(addr, eeprom);
}
/**
* Set DAC output voltage
* @param addr Device address
* @param vdd Device operating voltage, volts
* @param value Output value, volts
* @param eeprom Store value to device EEPROM if true
*/
inline void mcp4725_set_voltage(uint8_t addr, float vdd, float value, bool eeprom)
{
mcp4725_set_raw_output(addr, MCP4725_MAX_VALUE / vdd * value, eeprom);
}
#ifdef __cplusplus
}
#endif
#endif /* _EXTRAS_MCP4725_H_ */