Hangman

Hangman is a Bluetooth-enabled crane scale. It's intended use is as a climbing training and rehab tool, but it can be used anywhere that requires measuring force or weight.

The hardware retrofits a cheap (~$23) 150kg crane scale from Amazon with a custom PCB based around a Nordic nRF52 microcontroller and a differential ADC. The firmware uses Embassy, an embedded async framework written in Rust, as well as Nordic's SoftDevice Bluetooth stack.

Why?

Crane scales have become popular in the climbing community as a means to train and rehab fingers. This is a fun project to learn and practice various concepts I was unfamiliar or rusty with: BLE 101, async Rust on embedded, nRF52 development, SMT soldering and PCB design, etc. Maybe it'll even help my fingers get stronger.

Status

The scale is feature-complete. Weight measurement works great with the Progressor API and compatible tools. Battery life is guesstimated to be in the range of several months to a couple of years depending on usage.

Disclaimer

This is not an officially supported Google product. Wouldn't that be funny though?

This has no affiliation with Tindeq.