My UPS Pal
Everything about the board, in one place.
Board
- Size
- 36 × 58 mm, two layers
- Module
- ESP32-S3-WROOM-1-N16R8
- Memory
- 16 MB flash, 8 MB octal PSRAM
- Temperature
- Module rated to 65 °C
Power
- Input
- 5 V over USB
- Draw
- About 0.08 A (0.4 W) in normal operation
- Worst case
- About 0.5 A, so any 1 A USB charger is plenty
Ports
- UPS port
- USB-A host with switched, current-limited power (1 A)
- Computer port
- USB-C for power, programming and console, with auto-reset
- Protection
- ESD protection on both USB ports and a 3 A resettable fuse
- Lights
- STATUS and FAULT LEDs
- Display
- Header for an optional 0.96-inch OLED
- Buttons
- BOOT and RESET. Press BOOT five times to clear Wi-Fi and login.
Connectivity
- Wi-Fi
- 2.4 GHz, 802.11 b/g/n, up to 150 Mbps
- Setup
- Captive portal on
ups-esp32-XXXXat 192.168.4.1 - Address
ups-esp32-XXXX.localover mDNS, or a fixed IP if you set one- Remote
- Tailscale
Protocols
- NUT server
- TCP 3493, UPS name
ups. Reads need no login. - UPS input
- USB HID Power Device, polled
- Metrics
- Prometheus
/metrics, names follow nut_exporter - Web page
- Live readings, battery gauge, NUT connection string and UPS controls. Served over HTTPS.
- NUT commands
- Self-test, beeper and shutdown, if your UPS supports them. Shutdown needs
OFFtyped to arm it.
Works with
- Clients
- Home Assistant, Synology DSM, TrueNAS, unraid, Linux
upsmonandupsc, Prometheus - Tested UPSes
- See the tested list in the docs
Firmware
- Updates
- Over the air, one click to install. Rolls back on its own if an update is bad.
- Recovery
- Reconnects after a Wi-Fi drop or a UPS replug
- History
- Long history and an outage log
- Tailscale
- Built in, for private remote monitoring
- Login
- Needed for setup, web changes and NUT commands
- Build
- ESP-IDF v5.5.5
- Coming
- MQTT with Home Assistant discovery (planned)
Enclosure
- Printable with no supports. The cover snaps on, so no screws.
- Wall mount
- Two countersunk holes for #6 / 3.5 mm screws, 23 mm apart
- Details
- Light pipes for the LEDs and pinholes for RESET and BOOT
- Files
- Three-colour 3MF for Bambu Studio and Orca
Privacy
- Check-in
- On by default: hardware ID, firmware version, uptime and restart reason. One click turns it off.
- Anonymous stats
- Opt in to add make, model, readings, Wi-Fi signal and free memory
Licence
- Firmware
- GPL-3.0-or-later
- Name and logo
- Trademarked, not covered by the open licences