# Artifacts with scrolling text **URL:** \ **Category:** Uncategorized\ **Created:** [September 2, 2023, 3:56pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/artifacts-with-scrolling-text/720 "2023-09-02T15:56:14Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![eriknau](https://avatars.discourse-cdn.com/v4/letter/e/cc9497/32.png) [@eriknau](https://rpi-rgb-led-matrix.discourse.group/u/eriknau)\ **Post date:** [September 2, 2023, 3:56pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/artifacts-with-scrolling-text/720/1 "2023-09-02T15:56:14Z")
I’m running 3 daisy-chained 16x32 rgb matrices (adafruit) on a Raspberry Pi 4. Scrolling text is working well except for some artifacts in the pixels to the left of the characters. It’s not too bad with a single color r,g, or b but gets worse with multiple colors, especially white. To scroll the text I’m doing a os.system call to the scrolling-text-example with the following flags: ```auto sudo ./scrolling-text-example --led-rows=16 --led-chain=3 --led-slowdown-gpio=2 -l 1 -s 5 -f -C ``` EDIT: forgot to say I’m using the deprecated wiring scheme “classic-pi1” because I initially followed teh old Adafruit tutorial to wire it up, to be able to use that wiring I had to create a new mapping in /lib/hardware-mapping.c. So could my wiring potentially be the issue? So I’ve tested different values for led-slowdown-gpio and 2 is the best one. This is a speech-to-text-to-translation application so I’m using a USB mic, Python SpeechRecognition library, and calls to google speech-to-text and translate-shell for text translation, so reading through the troubleshooting tips for this library I suspect the SpeechRecognition.listen() call could be causing the static output on the display. Here are a couple video examples: [red](https://drive.google.com/file/d/1Bp3NhBrIOqx6zPlw4-ZseGfV35vHctd5/view?usp=sharing) [white](https://drive.google.com/file/d/1NqrK1Vn9muy7PaumDdKdcD-P4MemBa_U/view?usp=sharing) If anyone has tips on how to further troubleshoot I would appreciate input! ---
**Author:** ![eriknau](https://avatars.discourse-cdn.com/v4/letter/e/cc9497/32.png) [@eriknau](https://rpi-rgb-led-matrix.discourse.group/u/eriknau)\ **Post date:** [September 3, 2023, 3:00pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/artifacts-with-scrolling-text/720/2 "2023-09-03T15:00:19Z")
Further testing, nevermind the application I’m running it from, the artifacts continue to appear when I run scrolling-text-example straight from the command line, with a little bit on single colors and more with multiple colors. Here’s what I’m using in the function call: ```auto sudo ./scrolling-text-example --led-rows=16 --led-chain=3 --led-slowdown-gpio=2 -s 5 -f ../fonts/9x15.bdf -C 255,255,255 "How's it going?" ``` ---
**Author:** ![eriknau](https://avatars.discourse-cdn.com/v4/letter/e/cc9497/32.png) [@eriknau](https://rpi-rgb-led-matrix.discourse.group/u/eriknau)\ **Post date:** [September 3, 2023, 4:49pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/artifacts-with-scrolling-text/720/3 "2023-09-03T16:49:33Z")
I’m going to bite the bullet and try redoing the wiring with the “regular” mapping. ---
**Author:** ![eriknau](https://avatars.discourse-cdn.com/v4/letter/e/cc9497/32.png) [@eriknau](https://rpi-rgb-led-matrix.discourse.group/u/eriknau)\ **Post date:** [September 6, 2023, 2:11am UTC](https://rpi-rgb-led-matrix.discourse.group/t/artifacts-with-scrolling-text/720/4 "2023-09-06T02:11:03Z")
I rewired it according to the “regular” mapping with no change. ---
**Author:** ![loranto](https://avatars.discourse-cdn.com/v4/letter/l/a6a055/32.png) [@loranto](https://rpi-rgb-led-matrix.discourse.group/u/loranto)\ **Post date:** [September 12, 2023, 9:32am UTC](https://rpi-rgb-led-matrix.discourse.group/t/artifacts-with-scrolling-text/720/5 "2023-09-12T09:32:47Z")
Did you tried to change power supply? It could also be caused by cables that are too thin ---
**Author:** ![eriknau](https://avatars.discourse-cdn.com/v4/letter/e/cc9497/32.png) [@eriknau](https://rpi-rgb-led-matrix.discourse.group/u/eriknau)\ **Post date:** [September 16, 2023, 2:32pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/artifacts-with-scrolling-text/720/6 "2023-09-16T14:32:10Z")
Thank you for the suggestion. The power supply is 5V, 2100mA, seems like it should be sufficient. I have made a change in the code that appears to have minimized the effect due to making threading processes more efficient. Not completely gone but I think will be acceptable.