Our customer has been using a heavy-duty apple grader developed in 1980s. While the mechanical part of the machine was still operating very well after around 30 years of use, the condition of the electronic control unit was poor and the controller eventually stopped working.
Given that spare parts were extremely hard to reach and expensive, we proposed to build a new controller using today’s technology. We left the power supply, tensometers and power elements, but changed all control circuits.
The original system consisting of three PCBs (one for processor, one for memory and one for ADC) was exchanged to a single PCB with modern STM-32 MCU, graphic LCD display and interactive user interface. Besides the restoration of original functionality, the device has now an intuitive interface with the possibility of accurate machine calibration, storing the settings and statistics and optional data interchange with PC.