More power upgrades

A project log for LCD music display

Legible notes that don't cost a fortune

lion-mclionhead

lion mclionhead • 10/08/2026 at 08:12•0 Comments

The trackpad was problematic enough to spin off into its own project.

https://hackaday.io/project/206936-laptop-touchpad-to-usb

Basically some more redundancy in the firmware & more power supply soldering got it back to life again.

The 4.3V noted earlier was eventually deemed worthy of probing, since raspberry pi's are notoriously bad below 5V & it was traced to the problematic USB hubs again. Originally, the plugs closest to the leads were required to keep the raspberry pi's alive.

Replaced the fine pitched wire plugs with directly soldered leads, bringing the hubs up to 5V & the touchpad/raspberry pi up to 4.4V. Interestingly, the USB MIDI cable raised it to 4.4V. Without MIDI, it was 4.38.

There was still a lot of voltage drop in the stock, fine pitch USB cables going out of the hubs. The last cables came from a dollar store, many years ago when they were that cheap. The cables could be chopped down to the connectors but the existing mitigations seemed to be working well enough.

The next step would be scrapping USB as a connector. Only 4 connectors are used. The hubs take a lot more space than bare connectors.

Previous log

Trackpad faults

09/15/2026 at 21:23 • 0 comments

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