dacx578

Unified Rust driver for Texas Instruments DAC5578, DAC6578, and DAC7578 digital-to-analog converters.

This crate is built on top of the Rust embedded-hal and provides a single, resolution-aware and no_std compatible API for the entire DACx578 family.

Supported devices

Origin

This crate is based on the original open-source DAC5578 driver:

• API documentation: https://docs.rs/dac5578/
• GitHub repository: https://github.com/chmanie/dac5578
• Crates.io: https://crates.io/crates/dac5578

The original project provided a clean and minimal driver for the DAC5578.

This codebase extends that work by generalizing the implementation to support the full DACx578 family, adding:

• resolution-aware value encoding,
• support for multiple I²C addressing schemes,
• and improved test coverage,

while preserving the original command structure and API philosophy.

Note: This driver has been tested on real hardware with the DAC6578. The DAC5578 and DAC7578 are expected to behave identically (aside from resolution) based on the datasheets and the original DAC5578 driver, but have not been fully tested on hardware.

Features

• Supports all 8 output channels (A–H)
• Resolution-aware value handling (8 / 10 / 12 bits)
• Write, update, write-and-update, and global update commands
• Software reset and I²C general-call support
• Supports single-pin and dual-pin I²C addressing
• #![no_std] compatible
• Compatible with embedded-hal 1.0

Usage

Create a driver instance

Single address pin (legacy packages)

use dacx578::{DACx578, I2cAddress, AddrPin, DacResolution};
use embedded_hal_mock::eh1::i2c::Mock;

let i2c = Mock::new(&[]);

let mut dac = DACx578::new(
    i2c,
    I2cAddress::SinglePin { addr0: AddrPin::Low },
    DacResolution::Bits12,
);

Single address pin (TSSOP-16 (PW) Package)

use dacx578::{DACx578, I2cAddress, AddrPin, DacResolution};
use embedded_hal_mock::eh1::i2c::Mock;

let i2c = Mock::new(&[]);

let mut dac = DACx578::new(
    i2c,
    I2cAddress::DualPin {
        addr1: AddrPin::High,
        addr0: AddrPin::Low,
    },
    DacResolution::Bits10,
);

Write to a channel

use dacx578::Channel;

// Write a value and immediately update channel A
dac.write_and_update(Channel::A, 0x0FFF).unwrap();

The provided value is automatically masked and aligned according to the selected DAC resolution.

I²C Addressing

The DACx578 family supports multiple I²C addressing configurations depending on the package variant. This driver supports both single-pin and dual-pin address selection schemes.

Single-pin addressing (ADDR0)

Some DACx578 variants expose only a single address selection pin (ADDR0). In this case, the I²C address is determined solely by the state of this pin.

Use this configuration with:

I2cAddress::SinglePin { addr0 }

This mode matches the behavior of the original DAC5578 driver.

Dual-pin addressing (ADDR1 + ADDR0)

QFN-24 (RGE) package variants expose two address pins: ADDR1 and ADDR0. This allows up to 8 distinct I²C addresses on the same bus.

⚠️ The combination ADDR1 = Float and ADDR0 = Float is not supported by the hardware. Attempting to use this configuration will cause a panic.

Use this configuration with:

I2cAddress::DualPin { addr1, addr0 }

Notes

• The base address for all DACx578 devices is 0x48

• Address bits are derived directly from the pin configuration, following the TI datasheet

• The addressing mode does not affect command encoding or resolution handling

• Both modes are fully supported by the same DACx578 driver API

Datasheets

• DAC5578: https://www.ti.com/product/DAC5578
• DAC6578: https://www.ti.com/product/DAC6578
• DAC7578: https://www.ti.com/product/DAC7578

Possible Improvements

• Provide an async version for non-blocking I2C operations
• Support for the reference voltage (Vref) to allow writing values directly in volts
• Add an API to read DAC internal registers or status
• Expand testing to cover DAC5578 and DAC7578 for full compatibility
• Add support for the DAC \CLEAR and \LDAC pins to allow hardware-based reset and synchronized output updates

License

MIT OR Apache-2.0