The Pinecil is a $25 soldering iron from PINE64 that runs off any USB-C charging brick. Itʼs a surprisingly capable unit with performance that punches well above its price. (My wonderful Hakko FX-888D has seen little use since the Pinecil arrived!)

Internally it uses a BL706 RISC-V microcontroller from Bouffalo Lab, running the open-source IronOS firmware. The BL706 has a built-in Bluetooth Low Energy radio, and last week IronOS 2.21 was released adding BLE capability.

I thought Iʼd have a crack at building a companion app for this new capability1, and hereʼs what Iʼve come up with:

I promise that Iʼm usually pretty good at soldering—just not when looking through a camera 😅

PineTool displays live data from the iron and can configure its temperature setpoint. Iʼve found it much more ergonomic than using the two-button interface on the device.

Is this unnecessary? Absolutely. But I figure that thereʼs a good overlap between those who use open source RISC-V soldering irons, and those who would enjoy pretty live temperature and power charts while soldering 😁.

PineTool is available for free on the App Store today and the source code is on GitHub.

Footnotes

1. SwiftUI and Swift Charts made this tiny but non-trivial app comfortably possible to build in a Saturday afternoon—which was pretty amazing to me. ↩