How do I get the data from the serial port?

Question

I have a Ciseco XRF radio module and a Slice of Pi expansion board.

Using the program 'screen' works fine; I can see data being transmitted to the XRF module.

How do I get the data from the serial port, so I can do some processing on it? I tried perl but it didn't read anything.

Answer 1

I haven't tried this on a Pi, but I use python to access a serial port on a Beagle Bone. Python serial can be installed using sudo apt-get install python-serial

Then you can use the following code snippet:

import serial
serialport = serial.Serial("/dev/ttyS0", 9600, timeout=0.5)
serialport.write("What you want to send")
response = serialport.readlines(None)
print response

Obviously replacing "/dev/ttyS0" with the name of the serial port, and 9600 with the baud rate you need. response will be an array containing the lines which are returned by the serial port.

More details of the python API can be found at http://pyserial.sourceforge.net/

Answer 2

Great thanks,

The name of the serial port on a pi is: ttyAMA0

so my code is:

import serial
serialport = serial.Serial("/dev/ttyAMA0", 9600, timeout=0.5)
serialport.write("My string output to serial port")
response = serialport.readlines(None)
print response 

Answer 3

ttyAMA0 is the port name who ever found this out is a genius