Scale BLE Data Logging Upgrade

Rather good basic electronic scales are available at your choice of online retailers at a reasonable price. However, such scales don’t typically include wireless functionality or IoT tracking. Not satisfied with this state of affairs, Tech Dregs upgraded his basic scale for BLE functionality using a Seeed XIAO ESP32-C3 microcontroller.

This project follows a coffee grinder enhancement project that we covered here. Instead of gutting the scale to put the internals in a 3D-printed case as he did there, ‘Dregs added a Seeed XIAO ESP32-C3 dev board to the scale itself, along with a modified 1.3” OLED display. He also added a LiPo battery, though the only visible outer modification is a hole for the USB-C charging port from the XIAO.

While externally pristine, the guts of the scale are a different story. The battery compartment was heavily modified to fit the LiPo, while holder for the original display was modified to fit the new OLED screen. This OLED was even "shrunk" via some rather gratuitous circuit surgery, and the original control PCB was also heavily modified to allow it to interface with the XIAO.

In addition to the scale modification, ‘Dregs created an Android app using MIT App Inventor that logs data inputs. It’s quite responsive, updating scale values every 250ms, and data can be graphed, stored, and reviewed as needed. It’s quite a neat project, and Arduino/App Inventor Code is available on GitHub for your edification.