The problem is that you are connecting two non-compliant devices together. The Pi is, at best compatible. I'm not convinced that it is even compatible when powered down.It not a faulty cable, it a user connecting a faulty device, that doesn't adhere to HDMI specs, to safe in price, by not including an external power source, as it should have. There is a reason this device is much cheaper than conventional converters, its too cheap!
Errrr, what? care to explain that, I'm not getting it. Are you referring to the PI? What does it "sink" to?In this case you have a device that is non-compliant in that it sinks more than 10 mA when powered up and more than 55 when powered down
Note that the original thread is pretty old now, so the information in it may be out of date. Check with Adafruit to ensure that the device is safe.PacificDragon64 wrote:i am soo disappointed to read this thread after i purchased what looks to be this same device from Adafruit.
I am now totally confused. I was under the distinct impression that Adafruit was a trusted seller and sponsor of "safe" RaspberryPi accessories. Their description of this device leads me to believe that it works safely on the Pi.
"We tried this out with a Raspberry Pi and an old VGA monitor we had and found the display output to be very crisp and vivid. For use with a Raspberry Pi we suggest editing config.txt to set "hdmi_safe=1" output for best results (otherwise, the Pi may not 'recognize' the HDMI display and revert to composite output)"
Is this in fact the very same device described here in this thread?
Do I need to return it for fear of damaging my Pi?
Any help here would be greatly appreciated. Thanks in advance.
Disappointed in Vancouver.
Really good point.mahjongg wrote:Yes, all of the above is true.
Note that the more expensive (well built ones) use external PSU's, which is what I would expect if they contain frame buffers etc.
The extremely cheap "cable powered" ones probably only contain LVDS receivers, deserializers, and simple resistor ladder D/A converters for R G and B. And make no attempt to change anything in the signal resolutions and timings, just turn the HDMI LVDS signals into analog signals and sync signals.
They probably also usurp the power that would otherwise go to the monitors EEPROM, that is why you cannot get any monitor info, they need every mA.
mahjongg wrote:. But this will probably burn the fuse too. I saw some people played with the fuses to allow the Pi drain much more current. I am not sure whether this is good for the Pi or not, but considering how much time and effort and risk it takes to modify the Pi, it might be better to play with the hdmi-vga adapter. For example, do a little soldering job and have the adapter powered by external 5V power supply like a powered usb hub
Could you kindly post pictures/schematics of how you went about doing this ?pwinwood wrote:For what it is worth I have measured the current consumption of the "Neewer Black HDMI Input To VGA Adapter Converter" to be 400mA. There are two 800mA switch mode power supply chips in the Converter. Therefore it is likely to damage the diode on the Raspberry Pi board. To fix this I have added a separate power lead to the Converter to feed it with 5v from the USB hub - the power lead has a USB connector on the end of it. No current is consumed now from the Raspberry Pi HDMI interface because the protection diode is reverse biased.
Not really it was a while ago and the adaptor is now sealed up and in situ.arunagirinathar wrote:Could you kindly post pictures/schematics of how you went about doing this ?
I recently purchased a similar device from e-bay advertised as 100% compatible with Nexus (??) and Raspberry Pi only to find that ebay was full of scams (?) a week ago on elinux.com and that such boards could burn Pi's Diode and plausibly even cause the whole board to wreck.pwinwood wrote:Why the interest?
Users browsing this forum: Majestic-12 [Bot] and 23 guests