I have Gameduino 3X Dazzlers for: the Feather M4, and for Raspberry Pi Pico both running CircuitPython.
They work flawlessly with anything I own that was sold as a "monitor", ie 7" & 10" displays from Adafruit, an Epson projector, a Dell monitor, etc. However, I get "no signal" on anything that was sold as a "TV" (I have tested with: LG, Sony, Vizio, and Panasonic). I have seen a few questions that look somewhat similar to this on the forum but without a clear answer.
I have added a device that serves as an EDID Manager and injects 5V power, which seems to solve my "TV" no signal issues. Any idea why "TVs" are different from "monitors", and how I might be able to overcome the "no signal" issues without the device?
Last Edit: Jun 1, 2021 5:13:08 GMT -8 by dazzler42
Yes, this is the same issue that I and a number of other users have seen. I hope the developer either provides a solution or tells us what we can use as a simple and cost-effective workaround until the problem is solved.
The common theme here seems to be missing 5VDC on pin 18 of the HDMI connector. The connector is surface mounted and I don't want to risk damaging the board by trying to add a 5V jumper to pin 18 so I'm looking for a simple external solution. mattp and dazzler42 have both found a solution (Thanks!) but the "Dr. HDMI" device that worked for daxxler42 costs $79.
I just ordered a $14 powered HDMI splitter and will see if that works. If it doesn't solve the problem right out of the box, I'll dig into the switcher and add a 5V jumper to HDMI pin 18 if it's not already there. I'll probably start by putting a 100 or maybe 10 ohm resistor between the power supply and pin 18 to limit current. That may not be needed but seems like a good precaution for the initial test. www.amazon.com/HD-102-Powered-Splitter-Certified-Support/dp/B005HXFARS
Any other suggestions or proven solutions are welcome. James, PLEASE chime in here!
PS - John Leung of Tech Toys got back to me last night. Due to the chip shortage, some of the chips he needs are for his HDMI Shield are unavailable, others have gone up in price by 2-3x. He is unable to make them now so the Gameduino appears to be the only game in town for the time being.
For what it's worth, I found this HDMI male to female adapter with USB cable. It's cheap and may solve the issue but the description isn't clear on what the USB connection is doing (I assume providing 5V but who knows) and I don't want to wait for it to arrive from China. www.ebay.com/itm/313522491858
This might be an easier solution since it's an HDMI male to female pass-through that gives you access to all of the signals. If you plug this into the HDMI connector on the 3X Dazzler board and then plug your HDMI cable into the other end, you'll have a way to put the missing 5V on pin 18.
This $12 HDMI pass-through board with a jumper to simply connect 5V from the 3X Dazzler board to the "5V" pin on the pass-through has my Dazzler FINALLY displaying properly on a TV. www.ebay.com/itm/183489224010
My goal when I bought the board was to use the 3X Dazzler to provide a remake of the old "Pong" game to kids with disabilities allowing them to use their wheelchair joysticks as the paddle input. I have lost a month on this project because of the TV non-display problem. I confess that I'm a bit steamed as I wonder:
1) Why the 3X Dazzler wasn't tested with TVs since it seems that it only works with computer HDMI monitors.
2) Why has James Bowman not responded to any of our posts and information about the problem? He has also not responded to a message I sent to him through this forum a few weeks back. He has been on the forums a number of times recently but has not addressed this non-display issue in any way even though a few of us have now conclusively diagnosed the problem as a simple one of 5V not being applied to pin 18 of the HDMI connector.
3) Will James fix this on new production units and will he offer a fix for units in the field? All that is needed is to add a jumper wire from 5V to pin 18 on the Dazzler board but the HDMI connector pins are very tiny and very close. But it could be easily added to the next PCB rev and a pass-through jumper with 5V could solve the problems in the field.