Scroll pHAT HD as a Microsoft Surface Pro 3 5Ghz WLAN Jammer


Now this surely is some crazy interference side effect between a Scroll pHAT HD and a Microsoft Surface Pro 3. Whenever I run a cute little python script that scrolls information accross the Scroll pHAT HD like mad, the 5GHz WLAN access of my Microsoft Surface Pro 3 goes mad, too. After stopping the script, the WLAN access for the Surface Pro 3 recovers.

In contrast, the Surface Pro 3 has no issues using 2.4GHz WLAN even while the script constantly outputs to the Scroll pHAT HD.

Other devices, such as a Samsung Tab S, have no problems using 5Ghz WLAN while my Pi Zero W with its Scroll pHAT HD “radiates” (as in SPAMalot??). The Pi Zero W as such doesn’t cause the interference as I could cross-check.


I think we have a Surface Pro 3. Not to mention an RF spectrum analyser contraption. I don’t know if I’ll be able to convince @niko to rig an experiment though :D

LEDs, or at least the chips driving them, are infamous for emitting all kinds of noise due to the PWM switching frequency. Very odd that it’s isolated to 5Ghz on your Surface Pro 3 though.


Maybe interference might not be around 5GHz itself, but on some intermediate frequency (or a harmonic thereof) of the HF electronics?

To make this much more strange, I rebooted the SF3 Pro and the severe problems where (almost) gone, with only some very rare drop outs this day.