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hzeller / rpi-rgb-led-matrix

Controlling up to three chains of 64x64, 32x32, 16x32 or similar RGB LED displays using Raspberry Pi GPIO
GNU General Public License v2.0
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2 - 128x64 Boards and Characters are out of alignment at roughly line 32... #944

Open jbasemvd opened 4 years ago

jbasemvd commented 4 years ago

Using 2 128x64 Panels Chained. These are ABC typy using --led-row-addr-type=3. I'm using a 40 pixel font I downloaded from Google. I get something similar to the following on the display panel. I looked through the Issues here but wasn't able to locate anything that sounded similar.

Thanks in advance.

For the letter I: (Not to scale just showing how the alignment is shifted left)

oooo
oooo
oooo

oooo
oooo
oooo
oooo
oooo
oooo
oooo

oooo <-- Shifted Left at line 32 of 64 oooo oooo

hzeller commented 4 years ago

It is not really clear from your description and ASCII drawing what you mean with the shifting. But it can well be that this is just due to shift-register issues. It might well be that your hardware can't deal with the speed of the GPIO. Try a higher gpio-slowdown value.

jbasemvd commented 4 years ago

Hello Henner,

Thanks for sharing you code it’s been a great learning tool for me.

Here is an example of the shifting I was talking about. This doesn’t happen when the text is stationary only when scrolling. The first image is the stationary and the second image is scrolling. I’ve tried all of the GPIO speed variations. I’m using a Raspberry Pi 3.

Thanks for responding I appreciate your help.

Walt

From: Henner Zeller notifications@github.com Sent: Tuesday, December 24, 2019 12:50 AM To: hzeller/rpi-rgb-led-matrix rpi-rgb-led-matrix@noreply.github.com Cc: Walt White walt@waltwhite.com; Author author@noreply.github.com Subject: Re: [hzeller/rpi-rgb-led-matrix] 2 - 128x64 Boards and Characters are out of alignment at roughly line 32... (#944)

It is not really clear from your description and ASCII drawing what you mean with the shifting. But it can well be that this is just due to shift-register issues. It might well be that your hardware can't deal with the speed of the GPIO. Try a higher gpio-slowdown value.

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marcmerlin commented 4 years ago

@jbasemvd you should include a picture Also, are you getting the shifting if you use the demos that came with the library? If ~/rpi-rgb-led-matrix/examples-api-use/demo -D0 works without shifting, it's not the library's fault :)