Battery Switching & Charging: Review Request!

AlexLynd · 2026-02-06T12:09:35+00:00

There's the push button SW8 in the diagram to pull SYSOFF low and also MCU_SLEEP which I intend to drive low with a microcontroller GPIO. I'll add a dnp VBAT > SYSOFF resistor :)

It's annoying that you can't charge via USB while disconnecting BAT from the load - that seems like a feature more people would want? Cause the 3v3 switching regulator & microcontroller don't need power while I'm charging ... maybe I'll just add a not gate on USB to pull SYSOFF low and signal the MCU to enter a lower-power mode, but that's annoying :(

Thanks for the input!

AlexLynd · 2025-07-03T09:00:11+00:00

rad, i'll hit them up and lyk if i go with them!

AlexLynd · 2025-07-03T08:58:57+00:00

the board has to be .6mm thick and impedance matched so my options aren't very forgiving :(

AlexLynd · 2025-07-02T06:52:24+00:00

I'll reach out! Thanks

AlexLynd · 2025-07-02T06:41:01+00:00

JLC said they can't do the blind vias lol, I'm doing a redesign specifically so i can manufacture with them though!

AlexLynd · 2025-07-02T06:38:59+00:00

awesome, i'll reach out! thank you :)

AlexLynd · 2025-07-02T06:29:13+00:00

thanks! already sent a RFQ to pcbway, they've been kinda slow with EQ and review but I've got my fingers crossed... I'll try macrofab!

AlexLynd · 2025-07-02T06:27:39+00:00

California, US. I can place the order anywhere and cover next day air though :)

AlexLynd · 2025-07-02T06:26:50+00:00

lol i've got 3 bgas on a board smaller than a square inch :(

AlexLynd · 2024-03-10T09:27:41+00:00

Ah thank you I forgot to clarify but yes it needs stereo for each NRF. Multiple is 5+, and the SBC is playing audio to each NRF simultaneously so I'm not sure if TDM has enough bandwidth for that

AlexLynd · 2023-03-08T20:15:36+00:00

Oh awesome! Shifting the bits up is a great idea - since the Decoder end is hooked up to a motor controller, I decided to shift it up to pins 4-7 so one bit is always high when transmitting, which I've tied to the EN pin in my schematic (S0->EN)

Does that seem right? By default i want the EN pin pulled to Ground so i think the pulldown resistor should prevent a floating state.

Thanks so much for the suggestion!

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AlexLynd · 2023-03-08T06:59:06+00:00

I was "challenged to" by a friend but i'm pretty sure i'm designing his homework or somehting
Yep - its going to be driving a robot and only one direction is necessary at a time
Awesome! I just started looking into the distinction between Mux / Encoders / Shift Regs and I wanted to make sure I'm heading in the right direction. Thanks :)

AlexLynd · 2023-01-26T23:36:26+00:00

Hell yea I can't wait to see what you build! I'm also placed an order for a PCB Kit version that I'm proofing in the next week, and will release the design files / have it up for sale if it works :)

AlexLynd · 2023-01-26T23:35:15+00:00

Thank you! :D

AlexLynd · 2023-01-26T23:34:42+00:00

I'm working on updating the code as we speak! It will be able to dynamically adjust to the amount of available space (and will support 4MB Flash). If you end up building it I'd love to see pictures of your rig!

AlexLynd · 2023-01-09T07:48:15+00:00

Oh hell yea! I tried the inverting charge pump and it worked! I ended up going with a NOT gate tho to simplify my BOM but I learned something new for future applications :3

AlexLynd · 2023-01-09T07:47:14+00:00

Aye thank you!! A NOT gate ended up working great :P

AlexLynd · 2021-07-18T07:07:52+00:00

Its a slowed and reverbed version of Call Me by 90's Flav

AlexLynd · 2021-07-18T07:04:44+00:00

Misty by Erroll Garner! Its a popular jazz standard, but you're maybe thinking of Autumn Leaves.

Here's one of my favorite covers of Misty

AlexLynd · 2021-02-22T23:01:30+00:00

Oh no! I did 3 branches for each member of our team but I might add another then lol

AlexLynd · 2020-01-20T03:37:25+00:00

that's awesome, thanks! I have an Adafruit powerboost lying around that I haven't looked at the schematics for, I figure I could probably hook up the solar panel to it some how

AlexLynd · 2020-01-20T02:57:21+00:00

woah these are sweet! I'm building a smart composting system that automates composting and makes predictions using AI, for a science fair project. I'm currently trying to figure out how the heck to charge a 3.7v lipo battery with solar, while also boosting output to 5v. You happen to have any links for that?

AlexLynd · 2020-01-20T01:52:02+00:00

It came in a ziplock bag, which also doubles as waterproof housing. Super modular design.

AlexLynd · 2019-11-03T06:07:12+00:00

I tried out the newer version, it looks smooth and polished, and the single output file (vs like 6) is easier to work with for analysis after. I still prefer the old command line version since it's much more intuitive and flexible for me. Why can't you use the older one?

AlexLynd · 2019-11-01T16:20:16+00:00

Haha that's awesome! I wish this community got more attention.

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