have a rs232 thermal printer(avasys)...i put a max232cpe on the path of rs232 cable from printer...i gave 3.3 volt to power supply pin of max232cpe..and then to rx , tx , gnd raspberry...i used python and pyserial...but the printer don't do any reaction...why????
[import serial
import time


port = serial.Serial("/dev/ttyAMA0",baudrate=9600, timeout=1,
parity=serial.PARITY_NONE,
stopbits=serial.STOPBITS_ONE,
bytesize=serial.EIGHTBITS)

port.write('abcdefgh')]