The standard way to connect a serial port (RS232) to an Arduino (or any 0V/5V based serial interface) is to use a dedicated IC like MAX232A. With this IC, you don't need a 9V battery like with my ...

I've not been able to figure out how to enable it. I found various commands like options and configuration file options, but when I try any of them, I can no longer connect to the database as any user ...

– EASE connects Arduino boards, Arduino-like boards, and Arduino Shields for large-scale applications. – EtherCAT supports high-speed, 200 Mbps communication (200x faster than CAN-bus).

The official Arduino team has today announced the availability of a new learning resource for those looking to learn more about creating projects using Arduino via the new cloud.arduino.cc website ...