Pico VGA demo board instructions/information?

Support
#1

Hi all,

there does not seem to be any instructions or information around the pico vga demo board that i can find - no guides or demos (beyond raspberry pi’s foundation own).

For example:

  1. Why the extra usb power connector and when should you use that or the pico onboard connector?
  2. What does the run button do? Is it a reset button?
  3. Can you use head phones with the audio or line out for testing
  4. what resolution and frequency vga display is required for an image
  5. what do the a b and c buttons do? Are they user code usable?
  6. which of the pi foundation demos will run?

I would have thought there would be pimoroni demos and example code e.g. for access the sd card etc

If this information is available can you please point me in the right direction - I am no stranger to controllers but usually thats with some form of documentation to access the devices on the board

thanks

Shifters

#2

There is example code here.
pimoroni-pico/micropython/examples at main · pimoroni/pimoroni-pico (github.com)

#3

Have a look at the Pico hardware design guide. The VGA board is fully documented there.

I think the Pimoroni design follows this mostly.
I beleive the only examples are in the pico-playground directory. Some info in the repository GitHub - raspberrypi/pico-playground

Having siad that I have built some of the VGA examples and dropped onto the board but so far I am not getting any VGA output so would be interested if you have any sucsess! Going to try to find another VGA lead and also solder up another Pico to test. Will report back.

#4

You may want to try using this uf2 file, if you haven’t already.
Releases · pimoroni/pimoroni-pico (github.com)

#5

Hi Alphanumeric,

your link does not contain anything with regard to the VGA demo board - it is accessible in c++ only according to their website where as what you have linked only pointers to micropython examples for other boards.

Please correct me if i am wrong!

shifters

#6

No you are correct, I missed the c only note on that page, sorry about that.

#7

Thanks for the pdf link for the vga, but thats only part of the answers we need - in particular pimoroni own examples on how to use their board would be favorite!! (or at least which examples show which aspects of the board)

shifters

#8

Hi shifter
The hardware guide gives details for all of the board design not just the VGA. There are detailed descriptions of power options, audio circuits, user buttones etc. BTW the run button saves you unplugging USB to reprogram.

Hi, I agree it would be nice for Pimoroni to at least let us know which of the SDK examples thay have tested. So fare I can only get some of the audio examples to work. I cant get anything out of the VGA at all.

I have tried these examples from the Pico-Playground directory
Sound
Popcorn - get nothing
USB sound card - PC recognises pico as usb sound card and i get low quality audio out of PWM jack.
Sine_wave_i2c - Get a sine wave out of the PWM jack
Sine_Wave_PWM - Nothing
VGA
Demo1 - Nothing
hscroll_dma_tiles - Nothing
sprite_demo - Nothing
texmode -nothing

#9

So after a bit of digging on the raspberry pi Pico forum it turns out you have to use a differend board configuration file to get the correct pin mappings for the Demos.
From there

“Just a reminder for folks playing with the VGA Board. If you’re building code for the VGA Board remember to pass -DPICO_BOARD=vgaboard to CMake. The default pin settings, which are for Pico, aren’t going to be correct. See Unable to run demo's on Pico Demo Board · Issue #9 · raspberrypi/pico-playground · GitHub. If you have everything connected up and you’re not seeing any VGA output, this is probably the problem.”

So, from the pico_playground build directory just run cmake -D"PICO_BOARD=myboard" …
After this I now have VGA output and proper audio from the DAC output.

#10

Sorry, myboard should be replaced with vgaboard :)

#11

Hi bobtrex,

well done on the detective work!!! I agree pimoroni should have their own demo code examples and build files for this.

I am waiting on my new vga cable (had loads of them can’t find any!) and will then follow what you have done!

well done!

cheers

shifters

#12

any joy with examples for the buttons and access to the sd card?

shifters

#13

Just playing with the VGA and sound demos at the moment but will have a look. :)

#14

Looks like some one at Pimoroni has updated the sales page now with the link to the pdf and the cmake compile -D as you mention above bobtrex.

Also having up-to-date version of extras is necessary apparently. I have a shell script now that does a refresh and rebuild of all folders and examples as there seems to be changes on a regular basis.

Hopefully these examples will flesh out in time

shifters