Flicker when downloading data from internet (NYC Subway sign)

1

Hi, I have been using the amazing library with the python bindings to make my own NYC transit sign. It’s powered by a RPi 3 under Raspbian Lite.

However, whenever I do a feed = SubwayFeed(…) the matrix flickers as that library connects to the API from the MTA and downloads a bunch of data.

Not sure if anyone has done a similar project and figured out how to avoid the flicker. Or if someone has done an entirely different project but with a similar problem - flicker from internet access - and has found a solution.

I have gone through the suggestions on GitHub, but it seems the _limit_refresh_rate_hz thing is not implemented in the Python bindings.

I have tried _gpio_slowdown between 1 and 4, PWM_bits is set at 10. I have 2 32x64 panels only.

Thank you so much for your kind help!

PeterP

3

thank you for the tips, this made it work!

5

going to pwm-bits = 6 and pwm-lsb-ns = 276 made the difference. There still is sometimes a tiny bit of flicker, but it basically is gone.

6

Are you currently working for MTA?

7

No, I am not. Why?

Cheers,

Peter