I have updated tracking page (http://egm.cloud/balon/
) to include more information:
- Table showing all data sent by TTN network (this includes packets without valid GPS position).
- Chart showing plottable data (altitude, voltages, time to fix) changing over time.
I guess that data log table might be confusing, so small explanation is needed. Each of the packets actually contains 4 records, normally these are current one and then 3 historical 5 minutes apart (so that would be -5, -10 and -15 minutes from now). If the probe sleeps for longer time for some reason (e.g. capacitor voltage is too low for MCU and LoRa to operate, these records might be much older.
As there is no timestamp or even counter (hindsight 20/20
) in the data records (not to be confused with packets, 1 packet = 4 data records) when we do not have GPS fix, it is not trivial to restore historical data properly. Therefore I have opted to plot only current (last) records in the chart. But adding these would not add much value anyway, it would match interpolated curve very closely.
We have originally planned to transmit temperature as well. Unfortunately we have failed to bring temperature sensor to life so we have used this field to transmit information about time to fix instead. This data field is still incorrectly labeled as temperature in previous post, sorry for possible confusion.
I was quite surprised that the probe was able to keep transmitting all night (lowest capacitor voltage was about 2,3 V which is still about 0,3 V above LDO cutoff) before actually catching morning light again. Unfortunately TTN coverage in this part of world is not that great, so we might have to wait few days before receiving something again. Well, if it's still floating...