This project is a simple i2c 40 pin GPIO expander module based on the PCA9505 or the PCA9506.
The module is designed for daisychaining to support up to 8 modules giving a total of 320 GPIO, if you want to go further you might be able to use an other i2c port or an i2c switch giving pretty much infinite IO
It was designed under EasyEDA.
The module doesn't include pullups so be sure which chip you use, the PCA9505 has pullups the PCA9506 does not!
All images (pcb or schematic) are exported at 2x scale. All major format are here: easyeda, altium, image. Unfortunatly easyeda can't export to the kicad format yet but the files here should be enought
Multiple libraries exist for this chip:
| Language | Link |
|---|---|
| Arduino Library | https://github.com/tofuman0/PCA9505_06 |
| Circuitpython class | https://github.com/TheStaticTurtle/CircuitPython_PCA9505 |