The UM25(C) is an USB Power Meter by RD Tech. It can be found for less then €20 on AliExpress.
The specifications are: UM25C specifications:
- Display
- 1.44″ color LCD display
- 0-5 brightness setting
- Auto screen off time – 0 to 9 minutes
- Refresh rate – 2Hz
- Measurement Range & Accuracy
- Voltage – 4-24.000V ±0.5‰ + 2digits
- Current – 0-5.0000A ±1‰ + 4 digits
- Capacity – 0-99999mAh
- Energy accumulation – 0-99999mWh
- Load impedance – 0.8Ω-9999.9Ω
- Time range – 0-99h59min59s
- Temperature range – -10℃ to 100℃ ±3℃
- Connectivity – Bluetooth (C model)
- USB – 1x USB male port, 1x USB female port, 1x micro USB port, 1x USB 2.0 type C port
- Quick charge recognition mode – QC2.0, QC3.0, APPLE 2.4A/2.1A/ 1A/0.5A, Android DCP for SAMSUNG
- Misc – 4 buttons to navigate menus, Bluetooth switch
- Dimensions – 71.2mmx30.5mmx12.4mm(UM25C)
- Weight – 23.74g
It comes with a android and windows application for logging.
This tool is can be used to log the following samples:
- Amperage (A)
- Voltage (V)
- Wattage (W)
- Temperature (C).
- Data group Summed Amp (Ah)
- Data group Summed Watt (Wh)
(more to be added in future)
It outputs the samples to standard out.
This tool does not handle the bluetooth connection, use bluetoothct/blueman for this. You connect to the
/dev/rfcomm0 device.
You can also use this with an UM25 via a USB to serial cable.
The logfile can then be parsed f.e. gnuplot:
