MCP4725 ESP-IDF

An MCP4725 component on ESP-IDF. For an example, see https://github.com/Molorius/ESP32-Examples.

To add to a project, type: git submodule add https://github.com/Molorius/esp32-mcp4725.git components/mcp4725 into the base directory of your project.

Note that this does not initialize the I2C bus.

Table of Contents

• Enumerations
  • mcp4725_power_down_t
• Structures
  • mcp4725_config_t
  • mcp4725_eeprom_t
• Functions
  • mcp4725_set_voltage
  • mcp4725_power_down
  • mcp4725_read_eeprom
  • mcp4725_write_eeprom

Enumerations

enum mcp4725_power_down_t

The normal and power-down modes.

Values

• MCP4725_POWER_DOWN_0 = 0: Normal operation.
• MCP4725_POWER_DOWN_1: Power-Down with 1kΩ resistor to ground.
• MCP4725_POWER_DOWN_100: Power-Down with 100kΩ resistor to ground.
• MCP4725_POWER_DOWN_500: Power-Down with 500kΩ resistor to ground.

Structures

mcp4725_config_t

MCP4725 configuration.

Members

• i2c_port_t i2c_bus: The I2C bus the MCP4725 is connected to.
• uint8_t address: The I2C address.
• portBASE_TYPE ticks_to_wait: The maximum wait ticks for all functions.

Notes

• The I2C bus must be initialized before calling any functions.
• ticks_to_wait must be at least 1 tick

struct mcp4725_eeprom_t

Stores the eeprom data for reading and writing.

Members

• mcp4725_power_down_t power_down_mode: A normal or power-down mode on start.
• uint16_t input_data: Value to write on start.

Notes

• input_data must be no larger than 12 bits (4095).

Functions

esp_err_t mcp4725_set_voltage(mcp4725_config_t dac,uint16_t value)

Sets the voltage on the MCP4725.

Parameters

• dac: configuration of the bus, address, etc.
• value: value to write to dac.

Returns

• ESP_OK: Success
• ESP_ERR_INVALID_ARG: Parameter error
• ESP_FAIL: Sending command error, slave doesn’t ACK the transfer.
• ESP_ERR_INVALID_STATE I2C: Driver not installed or not in master mode.
• ESP_ERR_TIMEOUT: Operation timeout because the bus is busy.

Notes

• value must be no larger than 12 bits (4095).
• This will wake from power-down mode, if set.

esp_err_t mcp4725_power_down(mcp4725_config_t dac,mcp4725_power_down_t mode)

Puts the device into the desired power-down mode.

Parameters

• dac: configuration of the bus, address, etc.
• mode: the desired power-down mode.

Returns

• ESP_OK: Success
• ESP_ERR_INVALID_ARG: Parameter error
• ESP_FAIL: Sending command error, slave doesn’t ACK the transfer.
• ESP_ERR_INVALID_STATE I2C: Driver not installed or not in master mode.
• ESP_ERR_TIMEOUT: Operation timeout because the bus is busy.

Notes

• Also writes a value of 0 to the dac.

esp_err_t mcp4725_read_eeprom(mcp4725_config_t dac,mcp4725_eeprom_t* eeprom)

Read the values to be set at start from the eeprom and puts them in eeprom.

Parameters

• dac: configuration of the bus, address, etc.
• eeprom: structure to hold the saved values.

Returns

• ESP_OK: Success
• ESP_ERR_INVALID_ARG: Parameter error
• ESP_FAIL: Sending command error, slave doesn’t ACK the transfer.
• ESP_ERR_INVALID_STATE I2C: Driver not installed or not in master mode.
• ESP_ERR_TIMEOUT: Operation timeout because the bus is busy.

esp_err_t mcp4725_write_eeprom(mcp4725_config_t dac,mcp4725_eeprom_t eeprom)

Write values to be set at start to the eeprom.

Parameters

• dac: configuration of the bus, address, etc.
• eeprom: structure of the desired values.

Returns

• ESP_OK: Success
• ESP_ERR_INVALID_ARG: Parameter error
• ESP_FAIL: Sending command error, slave doesn’t ACK the transfer.
• ESP_ERR_INVALID_STATE I2C: Driver not installed or not in master mode.
• ESP_ERR_TIMEOUT: Operation timeout because the bus is busy.

Notes

• Wait roughly 40 milliseconds before making another I2C call.