Arduino newbie here...but trying to get an Arduino to talk directly to a Barco projector via RS232. I've confirmed that I have my commands correct in comparing the commands that I send via my computer/hyperterminal and watching the rs232 output of the Arduino...the commands I send from the computer via RS232 to the projector work, but the exact same commands via Arduino do nothing. My hunch is that this is because the RS232 voltage levels coming out of the arduino are not to the +9v/-9v that the projector is looking for...
So, my question is...how do I get the RS232 out of the Arduino up to the +9v/-9v RS232 spec??
I should say that I am getting RS232 commands out of it if I connect straight up to my computer, can see commands coming from the Arduino through the shifter...but the projector is not happy with it...
The shifter board you have will be fine for communicating with modern computers, but if you're talking to a device that expects true RS-232 (don't know for certain if that is true of your device), you do need the MAX232 or equivalent, hassle though it may be.