There are several applications for monitoring the fill level of bins for holding recyclable discards of various kinds. The idea is to use a LoRaWAN-capable device to monitor the fill level, and other bin “state” data, and notify the bin management service when the bin needs maintenance.
Bin maintenance usually means replacing the bin when full and carting the bin contents away for recycling. But it could also mean detecting when the contents need to be removed before 100% fill because they are generating heat, are too “wet” or smell too much, etc.
It’s hard to capture every case but with something like this Sentinel device:
mounted inside the bin, a BME280 measuring the temperature and humidity can keep track of inside environmental conditions, a BMA280 accelerometer can detect when the bin has been mechanically jarred or tipped over, a VEML6040 ambient light sensor can track when the bin lid is open, and a VL53L0 time-of-flight ranging sensor can track the fill level of the bin, which is the main function.
All of these sensors have been incorporated in a version of this Sentinel device which I am testing now. Average power usage measuring and logging sensor data once per minute and sending LoRaWAN updates once per ten minutes is ~40 uA. At this rate the Sentinel can monitor bin level for more than three years.
Here is a record of the distance from the Sentinel device to a wall in my house for the last week as part of a short-term (~80 day) power test:
The units are centimeters and you can see that the distance recorded is 34 cm plus or minus a few millimeters. The apparent jitter is partly due to diurnal temperature fluctuations in my house. The VL53L0 is a superbly accurate sensor, and certainly accurate enough to alert when a bin is full. The sensor itself is only a few dollars and is easily integrated into any pcb with an I2C bus.
We expect to begin deployment for these kinds of bin level measuring devices this year, with construction sites and hospitals likely first customers.