All the small things...

No, not a punk track, but in fact my lament at working in a very confined volumes!

I’ve attached photographs of the components I need to use…I’d like the USB port of the Trinket, the charge port and power port of tthe batter pack to all be avaliable, but I’m told it’s a bad idea to power the Trinket from USB while it’s also powered from the battery, so I was thinking of introducing a physical switch to disconnect power from the Trinket before trying to use the port.

I was thinking of soldering the JST pad on the back of the Trinket to the USB A socket VCC and ground, with the switch incorporated in the VCC line. when the switch is moved over, the Trinket gets power, when it’s moved away, the Trinket port is free to be used for maintenance, reprogramming etc.

It’s a three position switch, so I was thinking of having central = off, right = power to Trinket, left = power to recharging port from the charger. My experience with switches isn’t great, so if anyone hears a loud “bang”, I obviously got it wrong…

With that in mind…other than the challenges of wiring everything in such a smal space…will the suggest little “stack” of these components work…and should I be thinking about putting some sort of insulation between them? They will literally be cheek by jowl as in the last picture (lower right hand corner).


Do you have enough space for a little scrap of protoboard to solder things to? Something like these?

Those boards are available here (disclosure - this is my store, so I have an incentive to promote these)

Otherwise, if doing it without a scrap of PCB, just be careful with your soldering and be sure to use shrink tube to keep wires from shorting against eachother, and hot-glue everything in place to keep the connections from fatiguing if it's not in some sort of case with the parts rigidly mounted.

Nope, not really. I’ve had to design a holder to support it all, 3D printing version 4 now…final one I hope…versions 1-3 were found wanting in one way or another!

Pics attached are version 3 I think…

Your switch looks awfully big! I know there are smaller ones and ones with plastic cases(self insulating).

If you are using a Trinket and a 3.7 volt LiPo battery, Adafruit makes a charger that is advertised for the Pro Trinket, but in fact works just fine with the Trinket or any board with a battery and usb connection (and ground of course.) Then you can just leave the battery connected and plug the usb in when you need to recharge the battery. It even has 'charging' and 'done' LEDs. Here's a board I made using that charger with a Trinket M0: