I recently discovered the wonderful world of the Pico W. I’m working on a project that requires “flatness”. At this point I would like to power my Pico W with a battery that also has an easy way of charging.
I considered buying the Pimoroni Lipo Shim but since I don’t have header connections on my Pico W it would require a lot of soldering. It would also make my Pico W too “thick”.
I’m now considering buying a Pimoroni Lipo Amigo Pro. I was hoping to solder the Pico W GND and VSYS to the “device JST-PH” connector on the Lipo Amigo Pro.
Has anyone tried this before? There’s a topic on here from somebody “planning” to do this, but there are no results.
Tips and or advice are/is welcome. Thanks in advance and have a nice day.
I have an Amiga Pro wired up to a Pico W. I posted the following.
Wired up my Amigo Pro to a Pico W setup.
With just the GND, and VDEV wired to VSYS, battery state of charge is displayed. Not sure its correct though? It’s seems to be stuck at 50%. And no way of knowing if its being charged, other than the indicator on the Amigo Pro. There is no detection of power being applied to the Amigo Pro via the python code. Battery will only charge if power is being feed to the Amigo Pro USB C jack. The On Off button on the Amiga Pro works. Need to do more testing in this mode to see if the code needs to be changed?
If I also wire up the +5V from the Amigo Pro to VBUS, the charging indication function works. And my battery state of charge now shows 90% when running only on battery. Which is about right, as it was fully charged when I put that battery in storage. Battery will also be charged if you power the Pico W via its Micro USB Jack. The ON Off button only works when “only” on Battery Power though.
EDIT: Charging LED turned off while I was typing this post
EDIT: 2
After running about 4 hours battery state went down to ~60%. That’s about right I think. It’s running a PICO W, two 320x240 LCD’s, and a couple of i2c breakouts. It’s one 2200 mAh battery, and I haven’t run this setup from battery before. Not for any length of time anyway. Just to test my code.
I would not connect the VBUS to the Amigo Pro. You can do that if you want to use the Pico as the power-source for charging, but that is not what the amigo is meant for - it has it’s own usb-input and does some smart switching between battery and usb-power.
To be on the safe side, put a schottky diode inbetween amigo VDEV and Pico VSYS. This is necessary to prevent back-charging from VSYS to VDEV if the usb of the pico is in use. I am sometimes lazy and don’t add the diode, but then I disconnect the lipo while e.g. updating the software via usb.
The pico-datasheet has some interessting pages about powering the device.
Connecting the VBUS wire was in the back of my mind as “is this OK”?
I want to be able to monitor the battery state so I will be connecting it. I may just add a switch to my Proto Board to disconnect it when need be. Or use my custom cable as described below.
On that same note, I have a USB cable with the +5V wire cut. I use it to program / flash custom powered PICO setups. I have an Interstate 75 that has a dedicated supply for it and the panels. I don’t get enough current via the USB connector to drive it and the panels. And I don’t want it trying to back power the host device plugged into it.
Thank you for your input. I’m confused now. I just want to power my Pico with a battery and have an easy way to charge it every now and then. The Pico USB connection will only be used for programming. I’ve 3D printed my own case for the Pico; The USB connection for the Pico isn’t even visible when in the 3D printed case.
I just need basic powering for my Pico, that’s it.
Amigo Pro 5V to Pico VBUS
Amigo Pro VDEV to Pico VSYS
Amigo Pro - to Pico Ground
Do I need all 3? No need to monitor the battery % or something like that.
Battery (VDEV) is connected to VSYS. So measuring VSYS will give you the battery voltage, independent of VBUS connected or not.
If you want to measure charging with the Pico, things are more difficult. The amigo pro exposes the charging state via a resistor (third pin, “CH”). But you cannot feed this into the Pico. I use it for a LED at the front of my case (the amigo is inside).