Hi
I’m trying to work out if the Lipo shim for the Raspberry Pi Pico is compatible with a wave share LCD screen. From what I can work out (I’m new to the world of microcontrollers) they share a pin and I believe that means they are incompatible. Any help greatly appreciated.
Many thanks
It could come down to what pin is shared, and what said pin it does?
What pin is shared?
Thank you for the reply. If I’m reading things right it’s 38 (GND) and 39 (VSYS). I don’t think GND is an issue as there are other GND pins.
The Ground isn’t an issue. They will have a common ground anyway. With your setup vsys isn’t an issue either, that’s the V+ pin. Electrically nothing bad will happen. One issue you might hit is vsys and your display, if it’s using that pin for power. USB powered it’s +5v, but Pico Lipo powered it’s battery voltage. When running on battery vsys is battery voltage. Which is 4.4v fully charged, to I think the 3.2v minimum battery voltage cutoff / shutdown.
You’ll just have to see how things go when on battery. If the display (backlight) dims. I have a Lipo Shim, and Pico Lipo. Both have Pimoroni display packs attached. The displays are showing battery state. Battery voltage and charging state. I haven’t noticed any dimming when on battery. An option to set the backlight / brightness can extend your battery life. Lowering it will give you more time on battery.
Thank you for the reply. Looking at the data for the screen it requires 3.3V, so should be fine. Good to note about the backlight. Thank you for the information and help. Time to go shopping.
You should plan for long pins. The LiPo-shim will be between the Pico and the screen (unless you use a pin-multiplexer) and this requires longer pins than usual.
Thanks for that. I didn’t think of that.