Yes, it ran quite a lot longer on the 1F, but still hung.
I wired this up (see pic) to be more stable than the breadboard mess I had. The led on 1.8k resistor is gonna run a lot longer than I’ll take at lunch!!!
Can I isolate RX and TX or…oh I just need TX from the beagle for visibility!
1F 5.5v supercap (that battery was discharged to 3.96v). This one has more charge. Also put a 1000uf electrolytic on the soldered version, “because”.
Fred Kerr (mobile)
I’ll try again soon with my more stable circuit (*soldered), also with RX disconnected so I just get output from the Pocket Beagle and the only power input is from the battery circuit.
(*Soldered, so no loose breadboard connections, better current carrying capacity, etc.)
What is a good way to share log files? Mine can get verbose! I could store it somewhere and post a link - suggestions welcomed! I have a lot of possibilities, but just let me know what works best for you.
It runs well with the soldered implementation. My breadboards are a little cheap.
The attached minicom_20180830b.cap shows a boot with microUSB power from a wall wart (from my rpi3), then a boot with the battery circuit. I left both RX and TX attached; I’ll play with disconnecting them another time.
I’ll look into getting some “telemetry” info from the pocket beagle. I’m open to suggestions about things to add/log, etc. Also, I think this pocket beagle doesn’t have a fix that I got before - after the shutdown, things panic.
If anything else jumps out from the log file, please let me know!
minicom_20180830b.cap (44.8 KB)
I am looking for 10K NTC Thermistors with B=3480. How critical is the B value, or what range can I accept? Currently I am looking on Mouser.
Is there a specific or recommended battery pack? I’m just using an 18650 from a local surplus store.
Regarding the log file, I still need to do this:
sudo /opt/scripts/tools/developers/update_bootloader.sh
I’ll also look for 100K thermistor with B=3960
Fred:
The temperature coefficient is only important if you are going to use them as temperature monitors, and you are going to thermally/mechanically attach them to the battery.
If you are just trying to get the battery power supply to run, and are not concerned about battery temperatures, a fixed resistor will work fine.
— Graham
I am concerned about the battery temperature for safety in my office, house, and around my 4-year-old son. 
And I’m curious about logging stuff infinitum.
I have it working with a fixed resistor (without attempting charging yet).
I am concerned about the battery temperature for safety in my office, house, and around my 4-year-old son.
And I’m curious about logging stuff infinitum.
I have it working with a fixed resistor (without attempting charging yet).
Did you ever get your thermistor working and enable charging?
Hello, I had to put the charging project on hold but will pick it up again soon. I probably blocked excessively on finding an acceptable 10K NTC thermistor with the right B= value.
I connected a 6v 5amp battery and it broke my bricked my pocket beagle.