neogrid-tiny-v1

viernullvier
Tue, 07 Apr 2026 22:45:09 +0200

First production run of neogrid-tiny: 5 PCBs ordered from JLC, hand-assembled without stencil. Confirmed working.

Assembly notes:

LEDs can not be hand-soldered as the pads are only exposed on the bottom and not on the side. It is advised to use solder paste (can be applied with a toothpick) and do the soldering with a heat gun or hot plate.

The LED plastic housings will melt at higher temperatures. The best results have been achieved with low-temperature solder paste (~170°C) and a heat gun (low air speed) or hot plate at 190°C.

Components on the rear can be hand-soldered. Resistors are a bit tricky as they are tiny, but it is manageable. Pre-tin one of the pads, then slide the component onto the pad with the iron still in place. Let it anneal, then solder the other pad, then re-heat the first pad again for stress relief.

Socket headers need to be placed last since there are other components between them.

Errata:

E1. The top-left alignment hole for the rubber dome pad is offset by 0.5mm. Doesn't impair functionality.
E2. The outer mounting holes are placed directly below the rubber dome pad, making it hard to design an enclosure. Actually using the mounting holes is only possible either with low-profile bolt heads below the button pad (might be visible) or by clipping the button pad corners (might be too close).
E3. GPIO0 and GPIO1 are part of the keypad matrix and can therefore no longer be used for UART on the uEXT connector.
E4. Extension pads are not labelled, so one can easily attach the extension board on the wrong side by mistake (ask me how I know).