New voltage reading and metadata
Hello,
We are currently trying to connect a solar panel to a charger and a lithium battery so the AudioMoth dev can be left in the field for a longer period. The linear battery charger (Adafruit bq25185 USB / DC / Solar Charger with 5V Boost Board) provides a constant 5V to the AudioMoth as long as there is enough sun and the battery is not empty.
The problem is that the AudioMoth measures this voltage and writes 5V (or "greater than 4.9V" to be exact) in the metadata of the recordings. As a result, we cannot get a reading of the actual battery voltage.
The charger board has a pin (BAT) giving the voltage of the battery. As we want to monitor the battery voltage, we are looking for a way to read the BAT pin with the AudioMoth dev. Would the GPIO port be able to read it? And if yes, would there be a way to alter the metadata so that it would display these new readings? Or perhaps, in a cruder way, to generate and edit a file with the voltage of the battery?
Many thanks in advance,
Simon
Hi Simon,
The easiest solution would be to use the Adafruit BQ24074 board as you don't need the additional 5V boost which causes the battery measurement problem, and it may also create some additional SD card write noise: https://www.adafruit.com/product/4755? The AudioMoth is then powered directly from the Li-Ion battery. The battery voltage will never exceed 4.4V when charging, and when there is no charge current, you will measure the true voltage of the battery. Alex