Search found 7225 matches

by hoglet
Wed Jul 18, 2018 12:29 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

The User Guide is pretty much finished now. I've added a few more photos, and finished the section about Calibration.

I've also pushed a release to github that includes:
- the zip file for the SD Card
- a .ssd with a few simple test programs

Dave
by hoglet
Wed Jul 18, 2018 11:04 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

Would using a 3b+ provide any advantage, ignoring the larger form factor etc. I wounder if would be possible to do a zero, version for internal fitting, and a £b+ external version (but would only be worth doing if it provide any advantage over a zero). I don't think a Pi 3 B+ version would even wor...
by hoglet
Wed Jul 18, 2018 9:58 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

One other thing I should stress.... Please do fit the two PCB standoffs (between the Pi and the Hat) to the edge of the Pi with the switches. I didn't do this with my original test board (#01) and after a couple of weeks of heavy usage, the connector seems to have become a bit unreliable with all th...
by hoglet
Wed Jul 18, 2018 9:52 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

The instructions look great! Looking forward to the delivery :) All units (except for z0m8ied0g) have now been posted. The UK ones should arrive tomorrow (Royal Mail 1st Class Signed For). The USA one for Myelin should take about a week. On a different note, is anyone intending to use a Pi Zero W? ...
by hoglet
Tue Jul 17, 2018 9:22 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

Looking good. Was there anything particular you want people to try or test? A script if you will. Or just let us loose? Here's a few thoughts.... Testing on many machines would be useful. Each system will be a bit different timings wise. If I get time, I'll extend the info screen tomorrow to displa...
by hoglet
Tue Jul 17, 2018 8:53 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

I've started work on a User Guide here:
https://github.com/hoglet67/RGBtoHDMI/w ... User-Guide

Any questions, corrections or things that aren't clear please let me know.
by hoglet
Tue Jul 17, 2018 4:12 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

Hi Guys,

All the DIN to Molex cables now finished and everything is packaged and ready to go.

Everyone on the list should have just received a PM with payment details, and a request for your postal address.

Hopefully everything will get posted tomorrow.

regards

Dave
by hoglet
Mon Jul 16, 2018 8:12 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

Does PLLH allow the 50hz to be adjusted? Might it be possible to remove the frame delay in the future? Whilst waiting for the correct Molex pins to come from RS (which they just have!), I've been experimenting with the HDMI Pixel Clock. The first thing I wanted to explore is whether it's possible c...
by hoglet
Mon Jul 16, 2018 9:30 am
Forum: hardware
Topic: Electron RGB to VGI
Replies: 6
Views: 201

Re: Electron RGB to VGI

The RGB DIN connector is the same on both BBC B/BBC Master and Electron machines. However, the Electrons with earlier issue PCBs don't produce such a bright picture compared to the Beebs and the later Electron machines. The later Issue 6 Electrons buffer the RGB signals from the ULA with an extra 7...
by hoglet
Sun Jul 15, 2018 6:37 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

Does PLLH allow the 50hz to be adjusted? Might it be possible to remove the frame delay in the future? It does allow the HDMI Pixel clock to be adjusted, and all other timings derive from this. You can statically create a custom HDMI mode with an arbitrary pixel clock using the hdmi_timings stateme...
by hoglet
Sun Jul 15, 2018 5:43 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

I've always thought that the TV uses the centre of the pulse. That does seem to be the case. If it is easier to only support 7 or 8, rather than start + 1/2 width, I can change the rally-x default. I've update the Pi code to support two thesholds, so it does the right thing now with R3=7,8 and 9: h...
by hoglet
Sun Jul 15, 2018 3:50 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

(Edited above post slightly)
by hoglet
Sun Jul 15, 2018 3:49 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

I'm not near a beeb, but I would expect making the pulse wider would delay the effective timing and move the visible pixels to the left. OK, that's what my current implementation does. Is the idea behind this that a CRT would actually be using the centre of the pulse? I believe rally-x works in the...
by hoglet
Sun Jul 15, 2018 2:11 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

All fixable, but I'm glad to have found this before I sent the boards out! Good that you've found this info! Hopefully that will address the issues you were seeing. Will the CPLD be end user re-programmable if we do need to make any updates once you've sent the boards out? Yes it is, but you need a...
by hoglet
Sun Jul 15, 2018 1:46 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

The book Video Demystified ( pdf ) says: HSYNC# is asserted during the horizontal sync time each scan line, with the leading edge indication the start of a new line. and To ensure compatibility between various sources, horizontal counter should be reset by the leading edge of HSYNC#, not by the trai...
by hoglet
Sun Jul 15, 2018 1:12 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

It might be worth testing the 1,000 scroll demo in 3D Pool. OK, that's looking a bit more jerky (both horizontally and vertically) than when using the SCART input. ... Might try a small tweak to the CPLD to see if that improves things. Starting the CPLD counting from the leading (falling) edge of h...
by hoglet
Sun Jul 15, 2018 12:48 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

It might be worth testing the 1,000 scroll demo in 3D Pool. OK, that's looking a bit more jerky (both horizontally and vertically) than when using the SCART input. Do you know how this demo works? On the Horizontal, the CPLD starts it's counting on the trailing (rising) edge of Hsync. I'm actually ...
by hoglet
Sun Jul 15, 2018 12:42 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

PhilYoung wrote:
Sun Jul 15, 2018 12:35 pm
Thanks for the explanation, I'll just have to try it, eventually, and see how it looks.
I've just tried 1280x720 on my old Sony Bravia (which is then scaled to 1360x768). It actually didn't look too bad. Certainly better then when using the SCART input.
by hoglet
Sun Jul 15, 2018 10:16 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

I think you've said previously, Dave, that there's not much time left for the Pi's ARM CPU to do much if any image processing and still keep up with the frame rate. And while the GPU is surely capable of sophisticated rescaling, there's no documentation for a baremetal program to make use of. By de...
by hoglet
Sun Jul 15, 2018 10:12 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

I was only looking to match a CRT, which would be twice the current resolution. Being able to do better would be nula territory. I'm not promising that I won't ask for it in future, or saying that nobody wants it now ;) From the CRT experiments that I have done, +/-1 on the width is OK. I did find ...
by hoglet
Sun Jul 15, 2018 9:50 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

[I'd probably intend to get or build one of these eventually, my HDMI monitor (which is a repurposed laptop LCD) is 1280x800 which is a resolution that hasn't been mentioned yet. Do you forsee any problems with that - it works fine with a Raspberry Pi running Raspbian. 1280x800 is slightly problema...
by hoglet
Sat Jul 14, 2018 8:03 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

Elminster wrote:
Sat Jul 14, 2018 8:00 pm
A random 12inch monitor designed for CCTV's from some site on ebay. Unbranded. Will have to work it out when I have a moment.
That's very likely 1366x768, so let the fun begin!
by hoglet
Sat Jul 14, 2018 7:40 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

Are you considering monitors with DVI inputs as HDMI? From a video perspective, I understand that they're the same My DVI monitor has some odd native resolution. If it's relevant, I'll get you the details tomorrow. Yes, it's definitely possible to use a DVI monitor with a suitable mini-HDMI to DVI ...
by hoglet
Sat Jul 14, 2018 4:29 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

Here's a quick question for anyone getting an RGBtoHDMI in the hear future..... Can you tell me what the "native" resolution of your HDMI monitor is? I just want to check these resolutions work, and head off any possible issues with certain resolutions that are difficult to make good use of. If you ...
by hoglet
Sat Jul 14, 2018 4:25 pm
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 136
Views: 12018

Re: PiTubeDirect signalconverter for BBC Micro

I'm just waiting for a cable so i can use the Pi Zero externally on the BBC Master and see if it does it there? But once the BBC is on a quick press of the break is all it takes.Not too much trouble :!: It should work fine on the Master, that does a more comprehensive Tube test when the MOS boots.
by hoglet
Sat Jul 14, 2018 2:17 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

Elminster wrote:
Sat Jul 14, 2018 12:35 pm
Looking good. Finished breaking Daniel’s projects for now so ready to start breaking this.
That won't be hard!
by hoglet
Sat Jul 14, 2018 11:31 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

Another update... Yesterday I did a bit more on the software side: ebd2c801 Pi Firmware: Added info feature 349844f5 Pi Firmware: Improved OSD rendering performance in modes 0..6 94dac383 Pi Firmware: Fixed some OSD consistentency issues if mode changed while OSD active e41da53b Pi Firmware: Improve...
by hoglet
Sat Jul 14, 2018 7:09 am
Forum: hardware
Topic: Electron +Plus 1 + AP5 + MMFS question(s)
Replies: 8
Views: 189

Re: Electron +Plus 1 + AP5 + MMFS question(s)

When I first power up I can access the MMFS and it boots into BASIC, I can load programs and run them. However, after pressing Break or CTRL Break, I get Language? Is this a known issue or is there something up? I've had a fair amount of use of MMFS and the AP1/6 ROM, and not had any problems like ...
by hoglet
Fri Jul 13, 2018 7:09 am
Forum: hardware
Topic: Cheap web-modem for the beeb/master (and arc if ya like!)
Replies: 103
Views: 3323

Re: Cheap web-modem for the beeb/master (and arc if ya like!)

So back to looking at why it doesnt connect to Wifi. All the time I shall spend on it today. I am really just playing until you I get a freewifi to play with. And I have some soldering to do as well. (not for this. something else) Connect to WIFI: ATWIFI<ssid>,<key> Long shot, but do make sure you ...
by hoglet
Thu Jul 12, 2018 4:05 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 202
Views: 7292

Re: RGB to HDMI using a Pi Zero and a small CPLD

Here's a few photos of the "production line" getting ready to build a couple more boards:
IMG_1411.JPG
IMG_1412.JPG
IMG_1413.JPG
Just two more left to build now.

z0m8ied0g has asked for board #09, so there's just one left now.

Dave