What transmits when the pico is connected from a computer?

[espruino-discuss3]

Posted at 2017-04-27 by BookishGray

We are using the pico to display on a vga monitor (using the 'tv' module). The code runs fine when the pico is plugged into the computer (even when "disconnected"), but as soon as we unplug the cord, the code runs fine but the vga monitor does not display correctly (it flashes, jumps around the screen, and sometimes displays an error). We have tested a few things and don't think it's a power or memory issue, so it must be something the computer transmits to the pico even when it's not technically connected. Does anyone have any idea what could be causing the problem?

[espruino-discuss3]

Posted at 2017-04-27 by @gfwilliams

Hmm, that's odd - I've definitely had it working without a computer connected for http://www.espruino.com/Espruino+Home+Computer.

Which pins are you using for VGA? The same ones described here? http://www.espruino.com/Television

Have you used setDeepSleep(1)? If you had, that could easily cause you problems.

Otherwise, how are you powering the Pico?

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Posted at 2017-04-27 by BookishGray

Yes, we're using the same pins as described in espruino.com/Television. We're also not using setDeepSleep(1). We're powering the pico via a cord connecting the breadboard to an outlet. We've also used multiple cords before (as well as several battery packs).

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Posted at 2017-04-27 by @gfwilliams

Which pins do you use to connect the cord to the Pico?

And are you using the most recent firmware?

Please can you try using just the most basic VGA output example (so nothing else):

var g = require('tv').setup({ type : "vga",
  video : A7, // Pin - SPI MOSI Pin for Video output (MUST BE SPI1)
  hsync : A6, // Pin - pin to use for video horizontal sync
  vsync : A5, // Pin - pin to use for video vertical sync
  width : 220,
  height : 480,
  repeat : 1, // amount of times to repeat each line
});

g.drawLine(0,0,100,100);

And see if you still get the same problems?