PPK2 works in desktop app but reports no data using Python API on Linux

[Gurleen]

Hardware I am using:

Power Profiler Kit II (PPK2)

I am experiencing an issue where my PPK2 works perfectly when connected to my laptop using the official Power Profiler application, but fails to stream or report data when connected to a Raspberry Pi using the PPK2 api. 

When executing my script on the Raspberry Pi:

1. The API successfully initializes a serial connection.

2. I am able to toggle the device into Ammeter mode, and the physical status LED on the PPK2 changes to blue.

3. However, after this point, the device does not report any current data back over the interface, and it behaves as if it is unable to detect any incoming power or continuous measurement frames.

4. Sometimes it does report current measurements which are clearly incorrect or in microAmps. 

On my laptop with the app:

1. It works perfectly fine and I am able to measure current.

I need to switch to the API because of remote tests that I run. 

Thank you. 

[Amanda Hsieh]

Hi Gurleen, 

Here are some things you can try:

Check your connections and grounding

• Ensure the DUT ground is connected to the PPK2 even in Ampere Meter mode. See Grounding
• Confirm measurement cables are connected correctly — the PPK2 cannot measure negative currents. See PPK2 not measuring

Check for data loss

• Avoid USB hubs between the Raspberry Pi and the PPK2.
• Try switching between USB2 and USB3 ports if available.
• Update USB drivers and try a different USB cable. See Data loss with PPK2

Ampere mode power supply

• In Ampere Meter mode, the external voltage applied to the DUT must be within the 0.8–5.0 V range. The USB data/power connection to the PPK2 itself must always be connected.

You can also check this post.

Regards,
Amanda H.