mqtt
- 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.
- Record MQTT topics to a MikroTik router's SSD
A mosquitto_sub container on RouterOS 7.24 that appends every message on chosen MQTT topics to the router's SSD, one file per UTC day.
- Pulling plugs on purpose
The first power-bank test passed because a second supply was hiding the failure. What each test in the UPS project could prove, and what it couldn'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.