How to Make a Wireless Sensor Live for a Year on One Tiny Coin Cell Battery
This isn&#x27;t that crazy -- you can get something as available and low cost as an ESP8266 ($1.72 in singles) down to ~.01mA to ~.005mA if you implement the hardware watchdog timer, use sleep mode, remove extra LEDs, etc and keep the external libraries to a minimum. There&#x27;s a couple of other tricks, but it&#x27;s a good place to start.<p>By using a low leakage FET on the SDA SCL lines and sacrificing a bit of speed, you can have up 127 i2c sensors that only use power when they measure.<p>A good low quintescent current buck boost regulator can squeze every last bit of power for your chip even when the battery is basically at 0 capacity (2.7V for Lion, .8V for Alkaline) and use very little power on it&#x27;s own.<p>Dropping the system frequency can also improve performance.