I connected a vintage serial matrix receipt printer (Datamega DPN-233) via FTDI to my MacBook's USB. It performs its own self-test without problems, prints an example and the RS 232 configuration (19200.8.N.1) I tried 2 different USB-to-Serial adapters, both have the same problem:
- When I press the "Online Button" on the printer my MacBook receives a "v"
- When I press the "Online Button" on the printer again, my MacBook receives a "w" and so on...
- Whatever ESC-Code I send nothing happens, sometimes, after some commands the printer starts to print some garbage
- The printer can print 24 Characters in one line. After i sent 12 CR Strokes to it, it starts to print a complete Line of "=y=y=y=y=y=y=y=y=y=y=y=y" and performs a line feed.
- I already tried 9600 but the result is exactly the same.
- I configured the printer as XON/XOFF, when I detach the Rxd from the printer all the above doesn't work any more
- All the above happens when I use two different serial terminal emulations on my Mac (Serial and Arduino)
Does anyone have any suggestions? The serial communication seems to work. Is this an encoding problem?
stty -f /dev/<USBtty> 19200 & screen /dev/<USBtty> 19200
(replace <USBtty> with the name of your USB device's tty port)