Use PPK2 to measure current during boot, radio activity, or a settled low-power state. PPK2 can supply the target in source-meter mode or measure a target powered by an external supply in ampere-meter mode. Results appear in the Monitor’s Power tab.
Prepare
Connect the PPK2 by USB, close other software using it, and ask Embedder to check the device. Complete the requested Python and PPK2 package setup. Identify the USB port or serial number if several devices are attached.
Record the target’s required voltage, expected current, workload, and measurement duration before connecting its power path. Follow the PPK2 and board wiring instructions for the exact setup.
Supply the target
In source-meter mode, connect PPK2 output to target VDD and connect grounds. Specify a supply voltage from 800–5000 mV and ensure another source is not also powering the target.
In a hardware script, choose ppk2_use_source_meter() before setting the voltage with ppk2_set_source_voltage() and enabling the output with ppk2_power_on_dut(). State whether the target should remain powered after the measurement.
Measure an external supply
In ampere-meter mode, place the PPK2 current path between the external supply and target. Do not request a PPK2 source voltage or output-power control in this mode.
Use ppk2_use_ampere_meter() for this mode in a hardware script. Check for alternate power paths through USB and debugger connections. When using a development board’s current-measurement jumper, follow its measurement setup and restore the normal connection before ordinary debug use.
Capture and compare
In the Monitor’s Power tab, open setup, choose PPK2, select its device and measurement mode, and enter the voltage for source-meter mode. Press Start to begin the live view, Pause / Resume to control it, and Stop to finish and save the capture. The live view’s Sample rate is the number of statistics windows per second. Check the separate DUT power control for the intended final supply state.
For a bounded measurement, ask for a current trace and summary after a defined settling period. For a live check, ask Embedder to start streaming, observe the workload, and stop the stream when finished. Scripts can use ppk2_start_measuring(), ppk2_read_samples(), and ppk2_stop_measuring() for that sequence; include disconnection and the intended supply state in cleanup.
Save the firmware revision, measurement mode, supply voltage, workload, and settling period with the result. Compare the same interval and workload on subsequent runs. See Power analyzer for a common measurement checklist.
Select PPK2 and its USB port, then pick the meter mode that matches the physical switch:
- Ampere meter: another supply powers the DUT. Enter the actual supply voltage in Input mV so the SDK calibrates current correctly. The PPK2 measures no voltage in this mode, so voltage, power, and energy stay empty and saved captures omit those columns.
- Source meter: the PPK2 supplies the DUT. Set a source voltage from
800 to 5000 mV. Voltage, power, and energy come from the regulated output voltage.
The PPK2 acquires at 100000 samples/s. The Setup rate from 1 to 100 Hz selects software statistics windows over that acquisition; each window carries mean, minimum, and maximum current in amperes. The Setup panel hides the Joulescope range controls for a PPK2.
See live power controls for pausing, recording, and stopping the stream.
Troubleshoot
- Zero current: check the inline current path, selected mode, and supply state.
- Unexpected current: check USB, debugger, and other paths that may power the board.
- Voltage or power call rejected: use source-meter mode when PPK2 supplies the board; remove those calls in ampere-meter mode.
- Device unavailable: check USB, close competing applications, and complete the requested setup.
- Board stops after measurement: check the requested cleanup state and restore any measurement jumper before ordinary debug use.
Last modified on September 12, 2026
