[Jan] works with both physically as well as psychologically disabled individuals, a few of whom cannot read, making many of their tasks more difficult. Although [Jan] is not in a setting to teach reading or composing skills, he was able to develop an add-on gadget for the scales utilized in repackaging sweets to provide simple comments that the individual can interpret.
The gadget has three LEDs—red, green, as well as yellow—to suggest the bundle does not evaluate sufficient (red), evaluates as well much (yellow), or lies within an acceptable variety (green). The industrial scales at [Jan’s] work environment each have a serial output to link to a printer, which he utilized to send data to the device. An ATMega8 controls the lights as well as an connected LCD, with the usual trimpot to modification the display’s contrast as well as a rotary encoder to change the device’s settings. whatever fits snugly into a custom-made frosted acrylic enclosure, laser-cut at a regional hackerspace.
[Jan] provides a extensive guide to approaching each step on his Instructables page, together with source code as well as a number of pictures. See a video overview below, then enjoy one more scale hack: building one from scratch.