I have recently purchased a projector, and on the back, there is a Round RS232 port. After a quick google, I found this document which seems to describe a protocol that MIGHT (I'll need to do more research) be used to control the projectors functions, such as (what i'm interested in manipulating):
- Power On/Off
- Select Source (VGA/HDMI in my case)
- Volume +/-/mute
- Keystone +/-
But, I don't have any experience of Serial Programming, so I was wondering, what sort of circuitry would be appropriate to connect a Raspberry Pi's GPIO pins to the projectors RS232 Port?
Also, any information on libraries for reading from and writing to the serial port would be good?
I have tried Googling around, and have found a few resources, but I am not too sure on what I am looking at. Are there any nice, concise tutorials that should:
- How to wire a Raspi to a Serial Device safely
- How to write a program that can interact with the Serial device
I have done a bit more searching, and I have discovered that the input labelled RS232 on the back of the projector is a 3 Pin Mini Din Port. On this, I am also unsure which is the Tx, Rx, and Gnd, so if anyone has any help on that front, that would be brilliant
MANY YEARS LATER
(I have opted not to list this as an answer, as its slightly out of scope for the original question, and I didn't want to irk others looking for an RS232 solution)
Almost 4 years have gone by since I asked this, and I thought I would share my simpler solution.
I simply attached a 38 khz Infrared Transmitter (and Receiver for configuration), and then used LIRC to send the commands, which could be invoked as a script from wherever (PHP, Python, Java). This was so much easier to migrate than having to re-wire/re-code the Pi when I broke the first projector.