Working with Gad Shaanan Designs, an industrial design firm, the team created a low cost bathroom scale and blood pressure monitor pair. The scale used an Infra-Red (IR) LED to send data to a wall mounted display. The battery powered scale uses a low cost Microchip PIC16C56 to perform a delta-sigma analog to digital conversion, IR modulation and run-time scale calibration…all in firmware! The wall unit is based on a Hitachi H8/3027 and is the controller for the blood pressure monitor and LCD display. The system allowed up to 5 users to store and graph both their blood pressure and weight over 5 measurement periods.
