Another video output option: serial in, textual VGA out

BigEd · Post by **BigEd** » Fri Dec 28, 2012 3:25 pm

We've had several threads recently about different ways to display output from an SBC - I've made an index below.

I've just come across another one, for £24.00 from HobbyTronics: a small 5V board, serial-in and VGA-out. It uses a propeller chip to do all the work, which probably means the code could be customised or the board repurposed.

The output is textual, although there are some line and box characters available. It supports multiple (non-overlapping) scrolling subwindows, in the 100x50 character (800x600 pixel) display. Colours for foreground and background are set per-line, not per-window.

(There are five windows used in this demo image: the bottom line is a one-line-tall borderless window which for demo purposes shows the product info.)

Previous threads:
- Serial VGA display - about $50, several resolutions up to 800x480, includes sound generation and a uSD interface. Offers customisable fonts. Still available here but may be superseded by this device for $60
- Using smart LCDs as a cheap and easy output peripheral discusses self-contained LCD displays
- Gameduino could make a good GPU / coprocessor for 6502 about £42
- 320x200 or 320x240 Monochrome Text/Graphics Generator a project by 8bit, has reached at least the prototype stage. Several pointers to display modules in this topic.
- Concept & Design of 3.3V Parallel 16-bit VGA Boards is a work-in-progress homebuilt graphics project
- Papilio FPGA Shield for Arduino could be GPU for 6502 - but the kickstarter campaign was unsuccessful

BigDumbDinosaur · Post by **BigDumbDinosaur** » Fri Dec 28, 2012 7:52 pm

BigEd wrote:

I've just come across another one, for £24.00 from HobbyTronics: a small 5V board, serial-in and VGA-out. It uses a propeller chip to do all the work, which probably means the code could be customised or the board repurposed.

It looks like a better device for VGA than the Picasso unit, as less work appears to be required to generate and control the cursor, as well as manage different screen areas.

ChuckT · Post by **ChuckT** » Fri Dec 28, 2012 10:30 pm

I'm always looking for something better. This is video on a TFT screen on an STM32 chip:

Touch Screen Driver. (This is the video I want you to pay attention to:)
http://www.youtube.com/watch?feature=pl ... Sv9fKLKvKc

These are other videos that are good but the one I wanted to draw attention to is the video above:

http://www.youtube.com/watch?feature=pl ... 3tquHhJOyE
http://www.youtube.com/watch?feature=pl ... Rvh5v3pPiM

You can read about the displays and video on:

www.andybrown.me.uk

There are 3.3 and 5 volt options for the Arduino so I believe they can be ported for the 6502 but I have invested in ARM. ARM could be a GPU for the 6502 if you were to use small screens. I believe it could do video on other devices as well. I think the Propeller controller being sold is a good option but the text driver is MIT license on Parallax.com for free and you shouldn't have to pay for a premade board unless you like not having to do it all yourself. Unfortunately, I don't think only a handful of VGA controllers are the only option.

ChuckT · Post by **ChuckT** » Fri Dec 28, 2012 11:09 pm

I stumbled across this today:

Smart GPU

http://vizictechnologies.com/#

http://www.youtube.com/watch?v=kFiy6aV3 ... =fvwp&NR=1

I think I am in love.

BigEd · Post by **BigEd** » Sat Dec 29, 2012 7:31 am

So, that's a board for $64 with a 1.8inch LCD, again with a serial input. 3V3 and 5V compatible.
(Stupid Flash site which makes it difficult or impossible to capture a URL for the datasheet)

Or one for $89 with a 2.4inch LCD (and possibly more features)

ptorric · Post by **ptorric** » Sat Dec 29, 2012 11:17 am

it's a fascinating problem, better: there are some fascinating problems.

* memory (too much)
* character map (banking like in c64?)
* high frequency (dma?)

probably i forgot some others...

i just got a lms500hf01 from a broken tomtom navigator, i'm trying to figure out how to use and, of course, any suggestion are welcome.

btw: my primary problem is the connector, any suggestion on how to connect the 50pin to a whiteboard?

i think that having a "best of" links about past thread is a very nice idea, because it's not so easy search in this board.

ChuckT · Post by **ChuckT** » Sat Dec 29, 2012 4:22 pm

BigEd wrote:

So, that's a board for $64 with a 1.8inch LCD, again with a serial input. 3V3 and 5V compatible.
(Stupid Flash site which makes it difficult or impossible to capture a URL for the datasheet)

Or one for $89 with a 2.4inch LCD (and possibly more features)

If you want their features, it is that much but you can do it yourself. I used Andy's blog and he was nice to email me with lots of answers on how to get started and I am willing to help others a little but I am a novice. The latest STM32F4 board was about $16, the USB to Jtag connector was $50 (ouch) but there is an STLink for about $22 which no one has taught me to use instead. The size of touch TFT screens come in different sizes and cost but there are about four different kinds of controllers which work but Nokia screens and the iPhone screen works with the STM32F4. There are development boards on Ebay (if you know where to look) but they are more expensive and people who are developers buy them. There are one or two boards recommended in the STM forum and I have all of this information in email but there are programs that compile in C and there has been work on assembly language.

I have also bought some cortex M0 chips that are in dip form and they are programmable in BASIC and I also have TI's Stellaris board which was promoted for $5 and probably now sells for $10. There are cheaper boards on Mouser for the STM line with less memory and features but I want to go with the chips and I found Cortext M0 chips for 39 cents.

http://www.adafruit.com/blog/2012/11/13 ... cortex-m0/

http://www.adafruit.com/blog/2012/12/05 ... velopment/

BigEd · Post by **BigEd** » Fri Jan 04, 2013 11:33 pm

I should mention also Quinn Dunki's work-in-progress VGA board which is now complete at the hardware level: http://quinndunki.com/blondihacks/?p=1154

ChuckT · Post by **ChuckT** » Wed Jan 09, 2013 4:06 pm

The Raspberry Pi is cheap enough ($35), has 512 MB RAM, has HDMI and could do graphics for the 6502 as a cheap GPU.
Several companies sell the hardware to connect it to other electronics.

ChuckT · Post by **ChuckT** » Sat Jan 19, 2013 10:19 pm

OpenRISC ASIC chip fundraiser

Quote:

January 18 is OpenRISC day and the OpenRISC project currently is conducting a fundraiser.

“We are raising $250,000 to build the worlds first truly open source system on chip processor. Help make this happen by donating to the project today.

Money raised will be used to fabricate a batch of OpenRISC SOC ASIC chips that will be available for sale to individuals and product manufacturers.

The processor will be affordable, and competitive in mobile and embedded applications. The 32 bit RISC chip will run at an estimated 250Mhz, support Video, DDR2 Memory, Gigabit Ethernet, USB, Audio, Serial, PCI and run the Linux operating system. Individual processors will be sold for an estimated $5 per unit.

”

This chip will have video and if they can get it in ASIC, I think you could get it for $5 or less.

http://dangerousprototypes.com/2013/01/ ... undraiser/

ChuckT · Post by **ChuckT** » Fri Apr 12, 2013 2:42 am

There is another video option that could be hacked that I didn't mention before because the status of the boards were unknown but they have brought the product back:

Uzebox Starter Kit - v1.0
http://www.adafruit.com/products/1291

BigEd · Post by **BigEd** » Sun Apr 02, 2017 4:06 pm

From a related discussion nearby, the Parallax Propeller and the TellyMate get mentioned:

jim30109 wrote:

Part of me feels like it is cheating, but for my build I'm looking at using this:

http://www.batsocks.co.uk/products/Othe ... 20Tiny.htm

I have two on order. I plan to have a dedicated serial port (separate from the "console"). The programmable fonts is cool. (It is done differently depending on how much horsepower the processor used for the TellyMate has.) It is tiny, cheap, and easy to interface. Hopefully I'll have one on the bench in a week or two to tinker with.

Thanks,
Jim W4JBM

Martin_H wrote:

If you don't mind something modern, the Parallax Propeller chip makes a good video chip for composite or VGA video, and there's plenty of firmware available so no programming is required. It's used by many homebrew computer enthusiasts. For example the RetroBrew I/O board uses it for their CP/M system, Vince Briel uses it in his PockeTerm, and Jac Goudsmit uses it in his L-Star.