Austrian firm Controllino has based its programmable logic controllers (PLCs) on Arduino modules. This is an example of how so ... a range of interfaces including SPI, I2C, RS232, RS485, and an ...

[feynman17] realized he could use the Arduino SPI library to communicate with this chip and built a small programming shield with just a few resistors and a 8-pin DIP socket to mount an ATtiny10 ...