HDMI Converter Upgrade

-
One minor problem with working with the Raspeberry Pi is the lack of a VGA display output. I say minor because most of the time the Pi is being used with a TV with an HDMI input or in 'headless' mode where I am logging in from elsewhere on the network.

Over the years I have acquired a small number of LCD VGA displays and I have a couple of these in the workshop along with a 32-inch LCD TV I picked up. Being able to use one of these displays with the Raspberry Pi was always going to be handy so I needed an HDMI-to-VGA adapter. These aren't overly expensive (£15 will buy a good one from CPC), but always on the lookout for a bargain I purchased the one below on eBay for £2.50 (direct from China).

The problem is that the Raspberry Pi HDMI output has very limited current on the 5-volt line, not enough to successfully run the adapter. Also, the Pi checks the HDMI output very quickly for a display and the adapter needs time to boot up so being able to run it from a separate supply would be an advantage. The Pi can be programmed to lock to HDMI and also to delay in checking for a display, but I wanted to avoid that for the time being.

Cheap HDMI to VGA adapterThe adapter came apart very easily by simply prising the bezel out from around the VGA socket. The HDMI specification gave me pin 18 as the 5-volt line so I was able to identify that on my adapter this was a purple wire which went to a pad on the PCB marked '18' (Doh, but it is always a good idea to check!). An old lightweight USB cable did the job for power and after cutting the purple HDMI wire, I soldered the red USB wire in its place on the PCB and the black USB wire to a spare ground point. Interestingly this PCB had pads for both a micro-USB socket and a small DC power socket (maybe 1.7mm or so) so a more sophisticated upgrade would be possible.

I tested the set-up to check it was working and have now bored a hole and re-soldered the power cable to neaten the whole thing up. It looks pretty professional now and the picture quality on a Panasonic VGA monitor is excellent.

I'm thinking of buying another of these and hard-wiring it into another VGA monitor I have to give the monitor an HDMI input.

Comments

Post a Comment

Popular posts from this blog

Electronics Upcycling

-
Image
ELECTRONICS UPCYCLING FAQ CHECK OUT THE OTHER POSTS ON THIS BLOG FOR DETAILS ON REPAIRS AND UPGRADES GOING BACK OVER 10 YEARS - What's the story? I've been tinkering with circuits for over 40 years and have an MSc in microelectronics, and a few years ago realised I could combine this with saving the planet. Basically I'm Greta Thunberg with a soldering iron. - Saving the planet? Well every electronic item kept out of landfill reduces the amounts of dangerous 'forever chemicals', getting released into the environment. By repairing items or stripping out most of the reusable parts this reduces what ends up in landfill and ensures the components go into the correct recycling bins, such as hard plastic cases. - Don't the council do that? Up to a point, but information has emerged about huge amounts of European electronic waste being shipped to Africa and Asia where it continues to damage the environment and people's health, especially the women paid ...
Read more

Powered USB Hub - £2

-
Image
 I bought a couple of these little USB 2.0 hubs for £1 each in PoundWorld intending to adapt them to be powered hubs for use with RaspberryPi computers.  Alan here ( http://pihub.blogspot.co.uk/2012/06/raspberry-pi-power-supply-and-powered.html ) beat me to it, but I wanted to give it a go with a flying power socket.  As usual, heat-shrink sleeve comes in to save the day. I didn't like the original USB lead and plug so I bought a USB-to-Micro USB cable (again for £1) and cut it in half.  One end goes to power the RPi and the other is the input USB. The input USB has only 3 connections made, the red power wire is cut short and ignored.  I did connect the ground (GND) wire though because the purist in me doesn't like the idea of floating grounds (blame my MSc).   The output for power to the RPi via the micro USB plug only has the GND and +5v connections made and the other 2 signal lines were chopped short and ignored. The power input was made ...
Read more

Wind Up

-
Image
I was having a sandwich lunch down at Tyrella beach on the Co Down coast back in late September and went for a walk afterwards and found this thing half-buried in the sand. It turned out to be a boat immersion heater of some sort (I don't own a boat so maybe someone can enlighten me). There was an electrical element and 2 pipes coming out of the top and the bottom connection you can see in the photo. It must have been thrown overboard (assuming the boat it was on didn't sink!), maybe after being replaced. It had been in the sea a while by the looks of it, but being stainless steel it has started to polish up quite nicely. The lid is held on by 6 bolts and I gutted all the old gubbins out of it to get the cylinder itself. Willis Solasyphon Anyway, the basic plan is to wind 1 or 2 tight coils of 8mm microbore copper pipe like in the photo above and make a heat exchanger out of the cylinder. I've had a go at winding this type of coil before and it isn't easy, but I'd ...
Read more