# Temperature sensor

It uses a [TMP36](https://cloud.hodos.ro/wiki/ha/datasheets/TMP35_36_37.pdf) to read temperature and it is optimised for power consumption.  
It uses watch dog that wakes every 8s and increments a counter. Once the counter reaches a certain value (e.g. equivalent to 1 hour), it will read and send temperature to the gateway.  
Every 12 hours the voltage is also read and sent.

According to the [battery life calculator](https://www.allaboutcircuits.com/tools/battery-lifetime-calculator/), a cell coin battery with a capacity of `200mAh` should last for 
`~ 3 years`, given that:
- Current consumption of device during sleep is `4.5uA`
- Device wakes up every `hour`
- Current consumption of device during wake is `10mA`
- Duration of wake time is `1000 ms`

![Schematics](docs/temp_sensor_bb.png)