Video synthesis with P2 – which development board would you recommend?
Andrey Demenev
Posts: 382
in Propeller 2
Hi there!
It has been a long, long time since I was tinkering with Propeller chips. Now I finally have time for it again. I would like to explore video synthesis.
What would be a reasonable choice for a development board? Most likely I will need multiple chips interacting, and I would need to capture video from camera(s). Any advise?
Comments
Hi Andrey!
I'd imagine you'd want the Edge module with 32MB ram on board for video buffering?
So perhaps these:
https://www.parallax.com/product/p2-edge-module-with-32mb-ram/
https://www.parallax.com/product/p2-edge-breakout-board/
For video connector:
https://www.parallax.com/product/p2-es-eval-board-accessory-set/
(or just the HDMI and/or VGA breakouts in that kit... and maybe USB too if needed)
For audio:
https://www.parallax.com/product/p2-hd-audio-add-on-set/
(if you wanted to experiment with Audio in/out)
There are some other parts, like PropPlug and power supplies/cables, but you might have those. Or else they can be found detailed in the Pro starter bundle, so pick the parts/links you need from this page: https://www.parallax.com/product/propeller-2-developer-starter-bundle/
One tip... if you are using the #64029 breakout board for each of your "nodes", then that board provides a standard 0.1" header that you could use to jumper the VIN supply across to multiple boards, instead of needing VIN (5V) main power supplies to every board. The assorted cable pack lists all the available lengths, depending on how close or far you want your boards!
https://www.parallax.com/product/assorted-3-wire-extension-cable-30-pack/
You'd run the 3-pin connector from the bottom (hdr) row of one power header to the top (pwr) row of the next. If you go that way and need help just ask!
The same could be achieved with individual "dupont" style jumpers too - though I'd recommend using good quality ones so you're not burning time chasing intermittent power connection issues due to wobbly connectors! Good chance you have a bunch of these anyway!
Hopefully that gives some ideas along with what you wanted.
The SimpleP2++ made by @Rayman has audio in/out, VGA out, 2x USB, and pads for PSRAM on the bottom.
https://www.rayslogic.com/Store/SimpleP2Plus.html
The Qwiic interface could be used for I2C between boards if that’s fast enough for you.
I’m not familiar with video input, but the board has one P2 accessory header and a bunch of I/O pins brought out to build your own interfaces.
Huh, I guess I never looked, I didn't know Rayman was selling anything. His latest board is the "Propeller 2 Platform" - https://forums.parallax.com/discussion/comment/1563989/#Comment_1563989
That board is easily the best P2 board currently - I don't think he's put it on sale yet though. (The one I have has a B scribbled on it, so I guess it's no. 2 from the prototype run)
Thanks @Wuerfel_21 ... Trying to get new PNP machine in working order to fabricate some P2 Platform boards... Hopefully will have some next week. Have that off for Spring Break...
The P2 ADCs are good enough to capture composite video. https://forums.parallax.com/discussion/comment/1564107/#Comment_1564107 Definitely not studio quality but might work for some artistic applications. 2 cogs and 350kB of hub ram to capture 320x240 x30fps
Here's a board for one channel of DVI input. https://forums.parallax.com/discussion/175982/video-capture-and-playback-using-the-p2#latest
Thanks for your suggestions!
For video input, I decided to first try OV7670 camera – it has fairly simple and fast parallel digital interface and supports up to 640x480 resolution. And I am going to start with visual effects that do not need to buffer the whole frame
Some of the cameras will let you take "preview" at low resolution that can fit in P2 HUB RAM.
Yes, OV7670 can scale down to any resolution, down to 40x30
I've been reading about Spectre video synth (which is over 50 years old) and I loved the idea. Tried to imagine an implementation of the idea on Propeller, and realized it is most likely not possible. A simple FPGA would do just fine though.
Hi
Great to see that you tackle video for P2!
I have done some experiments with an ov7670 with FIFO module with P2. One caveat with that camera is, that with lower indoor light conditions, it switches over to a very slow mode and all the timing is ????
Newer cameras like the one used with espcam seem to cope much better with lower light.
Have fun, Christof
Christof, thanks! Good to know