nxp-pcf8523 0.3.0

A no-std driver for the NXP PCF8523 module.
Documentation

NXP PCF8523

#![no_std] driver for the NXP PCF8523 RTC and calendar module built on top of the Rust embedded-hal. Supported I2C modes include standard (100 kHz), fast (400 kHz) and fast+ (1000 kHz), and the module has a fixed I2C address of 0x68.

Usage

use nxp_pcf8523::Pcf8523;
use nxp_pcf8523::datetime::Pcf8523DateTime;

// configure I2C bus at 100, 400 or 1_000 kHz...

let mut pcf8523 = Pcf8523::new(i2c_bus).unwrap();
// 1:41:13PM on 08.21.2025
let dt = Pcf8523DateTime::new(13, 41, 13, 8, 21, 25).unwrap();
pcf8523.set_datetime(dt).unwrap();
pcf8523.set_power_management(PowerManagement::SwitchOverStandardOnLowDetectionOn).unwrap();
pcf8523.start().unwrap();
let now = pcf8523.now().unwrap();
let timestamp = now.timestamp();

Example

The current example is based upon an Adafruit Feather RP2040 RFM95 with an Adalogger FeatherWing RTC + SD (which has an on-board PCF8523):

  1. $ cd examples/rp2040
  2. $ cargo build
  3. Attach RP2040 feather target to host
  4. $ cargo run
  5. Attach featherwing to feather
  6. Press reset btn on featherwing
  7. The on-board LED will toggle on a 2s interval

Tests

From the root dir: $ cargo test

TODO

  • More hardware tests
  • CLKOUT

Resources

Datasheet

Acknowledgements

License