Case study of the temperature monitoring of a vaccine and medicine freezer. The probes inside the tank are read by a Raspberry PLC outside it, which raises an alarm to the supervisors at the limit, counts the days of each batch with its real-time clock, keeps a local database and sends the data to the cloud over Ethernet or Wi-Fi.

The PDF covers the challenge, the three jobs (watch, count, record), the system architecture with the signal list and the hardware used. Interactive version: vaccine cold storage monitoring case study online.