I like to share my examples of solar powered sensors (temperature, humidity, pressure) for Home Assistant using the BtHome protocol: XIAO MG24 (Arduino), XIAO nrf54l15 (nrf Connect)
Key features: with advertising interval of 15 seconds (i know, way to often for temperature, but this is my benchmark), the average current is ~40µA (MG24) and ~10µA (nrf54l15)
My diagnostic dashboard:
Comments:
- Voltage derivative is a history-graph, others are statistics-graph with 5 minute average.That’s why voltage derivative shows a more noisy signal.
- Packet loss is calculated based on a counter that increments with every sent packet. With some Home Assistant helpers (statistics, template) it’s easy to determine packet loss rate.
- MG24 has a 5F/6V SuperCap, 54L15 a 1.5F/5.5V SuperCap
- MG24 has a 6V 50mA solar panel with Z-diode to protect SuperCap
- 54L15 has a 5V 30mA solar panel without Z-diode
- All solar panels are not exposed to direct sunlight
PJ 