power
- Three shutdowns, three causes
A storage box behind a DJI power station went down three times in two days with the battery near 95 %. The journals gave three different endings.
- The UPS said 2 minutes at 95 %
A UPS monitor took the minimum of three runtime estimates and raised low battery at 95 %. One of them was the station's time to full charge.
- The DJI went silent for four hours
A DJI Power 2000 stopped advertising over Bluetooth while the monitor served its last reading as live. Then the observer revived its own four-hour-old state.
- The alert about the blackout needs the internet too
Power-cut alerts leave over an uplink the cut can take down: retries, per-channel queues, a router watchdog, and a status LED that goes dark.
- The pin template was for a different plug
Moving a Bluetooth-paired Tuya energy plug to OpenBeken without opening it, and the borrowed pin template that looked right and wasn't.
- A null battery reading cleared the low-battery alarm
Building the Go observer that serves two power stations to stock upsmon: six ways the first version could fail, and the outage test that went through.
- The DJI's grid flag is labeled charge type
A DJI Power 2000 over plaintext BLE: the documented grid byte never changed, input watts read 0 on grid, and the link drops were a 420 ms timeout.
- Twenty-five percent is a countdown
How a power station's MQTT readings should reach the machines that must shut down: a Go observer on the router that speaks NUT, as designed.
- Secure session ready. Battery: ?
Porting an encrypted BLE handshake from Python to an ESP32-S3: every step reported success, and the reads came back empty. The station sends its key twice.
- The power went out twice. My UPS log saw it once.
Monitoring a BLUETTI AC180 used as a home UPS from Linux over encrypted BLE: no account needed, but polling misses short outages and input watts lie.