Arduino and PLCs Hook Up Via RS232 and Modbus There is a thriving online developer community using RS232, Arduinos, and PLCs to build industrial and home automation systems on the familiar serial ...

The Arduino talks to a USB card reader using a USB host shield. Then it communicates with the PLC using an RS232 link and the DF1 protocol that most Allen Bradley PLCs understand.

[HC] took a gander around the Googles and saw a number of people trying to read NAND flash chips with an Arduino. It’s an interesting problem; at 16 Megahertz, [HC] is looking at about 60 nan… ...