infovore / aw9523_rp2040

AW9523 GPIO expander driver for RP2040.

AW9523 for RP2040

A demo of the AW9523 I2C GPIO expander for RP2040. The library is ported from the Adafruit Library for this; I've removed the Adafruit_I2CRegister abstraction provided by Adafruit_BusIO and just used raw Pico SDK i2c commands.

Currently this is configured for a pico_w in CMakeLists.txt; you should probably change that to pico for a regular board. I just had a Pico W on hand to test this with.

Connections

Connect an AW9523 over I2C, connecting SDA/SCL to GPIO4/5, respectively.

Connect pullups (around 4k7/5k6) between SDA/SCL and VCC.

Connect a push button between VCC and AW9523 pin 8. Connect a pull-up resistor between pin 8 and VCC.

Connect the cathodes of four LEDs to AW9523 IOs 1-4. Connect the anode to VCC. You do not need resistors.

Connect AW9523 VDD to 3V3, and GND to Ground.

Usage

By default, the demo will light LEDs on pins 1-4 at about 25% brightness.

Push the button to toggle to pulsing them through all brightnesses; each LED will be 90º out of phase, creating a scrolling effect. (I wouldn't recommend using floating point math and sin in a production object, but it'll do for our demo).

Library Usage

You need aw9523.cpp and aw9523.h included in your project via CMake, and then you'll be able to use and instantiate the library.