How to add a Li-Po supply part

Hello,

This is a newbie request, please. I would like to submit the attachmentRPi Pico TrafficLight.fzz (741.5 KB) to AISLER but I am totally ignorant about what part to use insert on the Breadboard (and adjust accordingly on PCB view) for the simplest Li-Po connection to run the Pico board in stand alone mode.

This exercise is simply to get comfortable in using AISLER services. I’m using the simplest tutorial from the Raspberry Pi Pico handbook. I need guidance on using the proper Frizting part and ensure adequate “real estate” space on the PCB. I did a basic/cursory search for Li-Po terminal part under Fritzing but I may not have chosen the right keyword(s) since the search did not return connectors but rather other boards(?).

I would like some guidance on what Fritzing part to use to indicate a Li-Po (3.3V?) terminal block with two types of arrangement:

  • stand-alone Li-Po operation

  • Li-Po charged from desktop/notebook (if at all this is practical - just for my knowledge purposes)

Without getting some boards from AISLER, I feel that I’m limiting my use of Fritzing to basic documentation. I have had too many duPont wires come loose on my breadboards! I need a little more permanent solution now. Many thanks for your understanding and guidance.

Kind regards.

While undesirable (because of no protection on discharge of the LI-PO which is dangerous!) a battery holder for 18650 cells is available here:

Reading pages 20 - 23 of the pico datasheet gives suggestions (and warnings!) about how to power the pico. I’d suggest the pchannel mosfet variant with the below (or similar) charger board is likely your best bet. You can take the charger input from the pico USB connector as shown, or connect the charger power to a coax barrel connector (available in core parts) to power it from a wall wart. There are also standalone protective circuits available, although I don’t know if there is a single cell version available as a Fritzing part, I remember a couple of multicell versions though.

There are several better options here. In general the necessary protective circuitry is built in to these devices (although you should verify that the one you are using has appropriate protection!) Note that bare li-po cells (as used in the battery holder above) can explode or catch fire if shorted, overcharged or overdischarged. The protective circuitry in a charger tries to prevent that by limiting the output current in a short and shutting off before the cell gets too discharged or over charged. This board along with the battery holder above may do what you need. It has the necessary charging circuit (and I expect, but don’t know for sure) appropriate protection circuitry.

Before ordering boards it is a good bet to export the sketch as gerber files and check the gerber files with a gerber viewer (I use gerbv from the Geda project, but there are lots of them) to make sure the parts all fit correctly.

Peter

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Hello @vanepp,

Thanks for the quick reply. Thanks for pointing out the reference to the datasheet (which I had casually browsed during the initial release but didn’t quite get a grip on it) but your accompanying notes will help me tremendously in digesting the information in a more practical manner.

I will certainly follow your advice on viewing the sketch using gerbv. Many, many thanks again for helping out because I can sustain the momentum at my end with your feedback.

Kind regards.