I have finally found time to play around with the Plasma 2040 board and an LED wire and it’s working great so far, connected to an USB port. But now, I am wondering how to power it once I have set it up and don’t need a USB connection anymore.
Obviously, I don’t want to just try out several options and risk frying the board. So, how can I power the board and the LED wire? I was thinking about the Raspberry Pi 4 or 5 power supply, or maybe a phone charger. Would that work?
This is what I’m currently using.
5V 4A (4000mA) switching power supply - UL Listed : ID 1466 : Adafruit Industries, Unique & fun DIY electronics and kits
I just cut the barrel jack off, and wired it up to the screw terminals. I have a 144 LED strip.
The Plasma is really convenient for a quick solution. I have bought a plug-in USB-C “charger” supply as even a decent make is not expensive - you only need 15W. You can power the strip separately if you need more than 3A; the 5V supply does not have to pass through the board which is what the above solution I think implies. Just common the ground connections.
If you are powering the board by injecting 5V back into the screw terminal then it might be advisable to wire a Schottky diode in series as I cannot see any other protection on the schematic. I would like to hear what Pimoroni has to say on this as the board does not appear to have the Vbus to Vsys protection diode that the Pico has.
The danger is not to the Plasma board - it does not care where the 5V comes from - but through the possibility of two 5V supplies interacting.
I made up a custom USB cable for programing it. The +V wire is cut. Only Data +, Data -, and Ground are wired up. I just leave the plasma powered with it’s custom power supply setup. That +5V can’t get to my PC via the USB cable.
So the power supply for the Raspberry Pi 4 should work to power the Plasma 2040 board then. The spec for it says 5.1V, 3A, 15W. I should have one of those lying around here, now I can put it to good use again.
I had forgotten about the Pi 4 supply having a USB-C connector. Thank you for that and I will dig mine out and try it later. It could be a useful, cost-effective stand by.
Edit: I do not have a Plasma hooked up but a Pi 4 supply has a Tiny FX happily driving a full set of LEDs.