Deep Sleep Current and Optimizing the BME280
Since the TinyLoRa Node does seem to get some interest in the last days the question of power consumption and deep sleep currents came up a few times. So here are some measurements I took as well as a way to potentially more than halve the deep sleep current when using one of the usual BME280 sensor modules.
Deep Sleep Current Measurements
I use the ATTiny84s deep sleep / powerdown feature and the internal watchdog to keep the power consumption low and get a useful battery life with a CR2032. To get an idea how good/bad this works I did some measurements. i
| Test Arrangement | Deep Sleep Current |
|---|---|
| TinyLoRa without a Sensor | ~ 4.4µA |
| TinyLoRa with BME280 Module (Stock) | ~ 10.7µA |
| TinyLoRa with BME280 Module (modified) | ~ 4.5µA |