matrix_demo fast scrolling

[thijstriemstra]

the matrix_demo.py has a 'fast scrolling' section, where a bunch of text is displayed using a scroll_delay of 0:

show_message(device, msg, fill="white", font=proportional(LCD_FONT), scroll_delay=0)

i'm using the fastest raspberry pi 3 and all I see is flickering for a few seconds, the whole 'fast scroll' is a little too fast it seems. I guess it makes sense when a scroll_delay of 0 is used?

scroll_delay=0.03 seems to a more reasonable value (although I'm not sure how this looks on an older, slower rpi).

[atchoo78]

0.03 was perfect, thanks!. When I installed this library on my RPi4 and watched the fast scrolling part of the demo, I was 99% sure that I had mixed up CS and ground wires. I was kinda expecting the smell of melted jumper cable (or CPU) 😆 On my Raspberry Pi 2B+, I can even read it (!).

On the other hand though:
The slow scrolling part is unbearable painfully slow on the RPi 2. I seem to remember there was some vaguely smilar issues back in the 90s, when there was certain PC games you just couldn't play anymore when the GHz barrier was crossed. Timing issues all over the place.