Decent Espresso Half Decent Scale (HDS)

The Half Decent Scale (HDS) is Decent Espresso's benchtop scale built to live under the group head: wide enough to weigh two cups side by side, and thin enough to hide inside the machine's drip tray. The interface is stripped down to two buttons: the round one turns the scale on and zeroes it, the square one starts and stops the timer.

It connects over Bluetooth Low Energy, USB-C and Wi-Fi, and talks directly to Decent Espresso's DE1 app to stop the extraction at a set in-cup weight; it also works with third-party brewing apps such as Beanconquerer, Cofycat and Espresso Log. The firmware and hardware are both open source, meant for anyone who wants to modify them or write their own integrations, and update over USB or Wi-Fi. Power comes from a built-in rechargeable battery, or it stays on continuously when left plugged in over USB; a 50 gram calibration weight ships in the box so you can check its own accuracy.

It suits someone already running, or planning to run, an extraction-control app: unplugged from any phone or machine, it is still a precise two-button scale with a timer.