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PPK2

This example shows power-profiling with the Nordic PPK2 in ampere-meter mode. It is designed to work with the nRF53DK but can easily be used with other hardware.

nRF53DK Usage

One way to use this example code is with the nRF53 development kit. The trace of SB40 (directly behind connector P22) must be cut, making it open. Then, connect the PPK2 as follows:

  • PPK2 GND to External Supply (P21) GND
  • PPK2 VOUT (red wire) to the pin of P22 that is closest to the edge of the board
  • PPK2 VIN (brown wire) to the pin of P22 that is closest to the USB connector

This effectively places the PPK2 in series with the nRF53DK's application processor power supply. The PPK2 itself must be plugged into the gateway with a micro-USB cable. Make sure you use the port labeled "DATA/POWER" and not the one for power only.

When you are done, simply install a jumper across P22 to restore normal DK operation.

Other Systems

This example code can also be used with other development boards or hardware setups, provided you have the ability to insert the PPK2 in series with the processor's power supply. Refer to Nordic's official documentation for instructions on connecting to a DUT.

This project consists of two files:

conftest.py - Implements a fixture that flashes firmware, connects to the PPK2, and opens it for data collection

test_ppk2.py - Contains a test that collects current measurements and calculates average power consumption

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import os
import pytest
import time
import logging
import pytest_asyncio

from hil_sdk.interfaces.ppk2.ppk2_interface import PPK2Interface

@pytest.fixture(scope="session", autouse=True)
def ppk2_fixture():

    # This fixture is called first during the test session.
    # This is because ppk.set_device_power() must be called
    # for the DUT processor to power on and be flashed.

    ppk = PPK2Interface()

    assert ppk.open() == True
    logging.info("PPK2 opened...")

    assert ppk.set_ampere_meter_mode()
    assert ppk.set_device_power(True)

    yield ppk

    assert ppk.close() == True
    logging.info("PPK2 closed...")

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import time
import statistics

POWER_SUPPLY_MV = 5000  # 5V USB power supply

def test_ppk(ppk2_fixture):

    assert ppk2_fixture.start_measuring()
    time.sleep(5)
    ppk2_fixture.stop_measuring()

    # Measurements are originally in amps
    avg_current_mA = statistics.mean(ppk2_fixture.get_samples()) * 1000

    print(f"Average current: {avg_current_mA} mA")
    print(f"Average power consumption: {avg_current_mA * POWER_SUPPLY_MV} mW")