Reading data once every day. As the oil level is not going to decrease significantly every hour, it's overkill to read the meter very frequently like every few minutes or hours. The smart meter wakes up every 24 hours, takes a picture, runs the inference to predict the reading, connects to the cellular network, and sends data to AWS IoT Core over MQTT. The whole process takes around 150 seconds. The rest of the time the device goes to deep sleep mode, drawing about 300 μA.