Hi ya’ll,
Okay - this is all pretty much fixed. I want to fix one more little thing and I’ll push out an alpha build tomorrow.
There were three different areas where accidentally too much power burn had crept in over the last monthish. The three main problems were:
- GPS was not being kept off while main CPU is in light-sleep state or when we are not actively trying to get a GPS reading
- GPS was not powered down most of the time. Now we turn it on, get a reading (takes typically about 10 secs with good view of sky, could be up to two min worst case and then turn it off until we need another reading). For non routers we’ll do this every two minutes, for routers it does it once per day, though in either case you can change these intervals to whatever you want.
- We were not properly entering light sleep state, so we were burning 22mA extra while in light sleep
- We were staying in bluetooth enabled mode for a long time, which is not good for routers.
Measurements after (I’ll put these into the runtime calculator spreadsheet soon) (all measurements from a high accuracy 4V bench supply on a sx1272 based TBEAM):
- 180mA max current draw (screen on, xmitting, gps on, cpu running)
- 100mA when GPS + screen + bluetooth on
- 44mA when screen + bluetooth on (GPS powered down)
- 32mA when bluetooth on (GPS and screen powered down - “DARK” power management state)
- 11mA when cpu in light sleep (only lora radio powered, ready to wake everything else based on packet rx, timer expire, button press etc). <- This is the state nodes spend almost all of their time - it dominates the power calculations. I’m super happy that this number is now so low, it is half of the old lower limit.
I’ve also added the beginnings of router-mode, which includes a low-power-mode option for solar powered nodes. The new python tool is released to enable this mode “meshtastic --set-router”. But don’t use this option until I release the new device code. I want to fix an unrelated bug before pushing out a release. I’ll push this out tomorrow.