Industrial Refrigeration Monitor
Monitors temperature and humidity of walk in refrigerators. Adopted by a large global fast food, burger outlet chain.
Designed by me to provide temperature and humidity information from walk in refrigerators in fast food burger outlets. The device needed to communicate enough through the metal walls of refrigeration units to reliably pickup the signal. Standard LoRa at 915MHz proved to be sufficient. The device also needed to run on a battery for at least 12 months. To achieve this a very low quiescent current switching regulator was used, with the device in deep sleep between brief transmissions. The board was mounted upside down in the enclosure to avoid condensation build up on the sensor on the right of the photo. The device has an internal heating unit precisely for this purpose. However because of its relatively high power consumption, heater use was kept to a minimum.