PCA9535

PCA9535 IO-Expander driver using embedded-hal.

Features

Two expander modes:

• Immediate
• Cached

Immediate mode issues an i2c bus transaction on each function call, behaving like a normal i2c device library does.

Cached mode takes advantage of the interrupt pin of the device, which indicates a change in the register value. The driver holds an internal representation of the device's registers and thus it only issues a read if any data changed as indicated by the interrupt pin. This mode reduces read access on the bus significantly compared to immediate mode.

Two ways of interacting:

• Standard Interface
• HAL Pin Interface

The standard interface offers all needed functions to interact with the GPIO pins of the device.

The HAL Pin Interface offers a way to use the Expander GPIO as embedded-hal GPIO which makes it possible to use them in any other libraries using embedded-hal. The pins are usable across threads using an ExpanderMutex.

Usage Example

This is a basic usage example, for more information visit the docs.

Immediate expander using standard interface: ```rust use pca9535::{GPIOBank, Pca9535Immediate, StandardExpanderInterface};

let i2c = I2c::new().unwrap();

let mut expander = Pca9535Immediate::new(i2c, 32);

expander.pinintoinput(GPIOBank::Bank0, 4).unwrap(); expander.pinintooutput(GPIOBank::Bank1, 6).unwrap();

if expander.pinishigh(GPIOBank::Bank0, 4).unwrap() { expander.pinsethigh(GPIOBank::Bank1, 6).unwrap(); } ```

Cached expander using hal pin interface: ```rust use std::sync::Mutex; use embedded_hal::digital::blocking::{InputPin, OutputPin}; use pca9535::{ExpanderInputPin, ExpanderOutputPin, GPIOBank, IoExpander, Pca9535Cached, PinState};

let i2c = I2c::new().unwrap(); let interruptpin = Gpio::new().unwrap().get(1).unwrap().intoinput();

let expander = Pca9535Cached::new(i2c, 32, &interruptpin, true).unwrap(); let ioexpander: IoExpander, _> = IoExpander::new(expander);

let inputpin = ExpanderInputPin::new(&ioexpander, GPIOBank::Bank0, 4).unwrap(); let mut outputpin = ExpanderOutputPin::new(&ioexpander, GPIOBank::Bank1, 6, PinState::Low).unwrap();

if inputpin.ishigh().unwrap() { outputpin.sethigh().unwrap(); } ```