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zanppa / ballast-emulator

Ballast emulator to allow running a video projector without the lamp
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USHIO Ballast Emulation for Sanyo PLC-XT35L #1

Open belveder79 opened 5 months ago

belveder79 commented 5 months ago

Hi and thx for posting your design. You wrote in the documentation that you have a Canon projector with an Ushio Ballast. The Sanyo PLC-XT35L has also an Ushio ballast, but I wonder why I can't read (sniff) a single message from the UART bus - it just gives me nothing... would be great if we could discuss...

belveder79 commented 2 months ago

@zanppa can you give me some instructions?

zanppa commented 2 weeks ago

Hi.

Sorry for the delay, I somehow completely missed your messages. I still have the projector and can give you some references on what I did.

First I checked the power supply (ballast) connection to the projector. There was 3 optocouplers (1 signal from the projector, 2 from the ballast): kuva

I copied that circuit to my own board with similar 3 optocouplers, which I soldered to the connector pins (or maybe test points next to the connector, but same idea): kuva

The secondary side of those optocouplers I then connected to a Raspberry PI computer io ports such that I could read and write the messages with some simple python code (see serial-read.py and serial-send.py). I could use this to verify the parameters and messages enough that the projector does indeed turn on.

Before any Raspberry PI things though I used an oscilloscope to measure the secondary side of the optocouplers on the custom board to verify that the projector indeed was sending any data, and the signal levels were good etc.

I could not do any measurements or data logging with a working lamp, so I had to resort to some measurements done by other people aronund the net, and deduce the proper parameter and messages from those...

zanppa commented 2 weeks ago

If it helps @belveder79 , I found my old writeup and uploaded the part relevant to the protocol investigation. Maybe that helps you also forward? Protocol investigation

P.s. seems like I did not remember the optocoupler directions correctly. 2 from projector and 1 from ballast, and I seem to have used Tiva Launchpad instead of Raspberry Pi according to my notes...