I was looking for a way to send interrupts from Arduino to my macbook, without performing polling on a port. Here is a simple attempt to make it work. em-serialport is eventmachine compatible asynchronous library based on ruby-serialport.
The operation is simple. Whenever data is is available over serial port, on_data callback gets invoked. Similarly send_data writes the data on serial port.
gem install em-serialport
If you are on Mac, you need to set up a virtual USB serial port by installing a driver from http://www.ftdichip.com/Drivers/VCP.htm. Identify your serial port device. For ex: /dev/tty.usbserial-xxxxxxxx
EM.run do serial = EventMachine.open_serial('/dev/tty.usbserial-xxxxxxxx', 9600, 8, 1, 0) serial.send_data "foo" serial.on_data do |data| # you got data. Eat it. end end
The gem comes with a simple command line Serial Monitor. Launch it as:
bundle exec serial-monitor /dev/tty.usbserial-xxxxxxxx
Here is a working example, tested with an https://github.com/railsbob/arduino-examples/tree/master/echo_server. It simply reads and writes data to serial port from command line.
Serial monitor initialized. Enter data followed by a newline character. Ctrl-C to stop hello received: hello A very long sentence received: A v received: ery long received: sentence