Stuck: Unable to get an Uno R4 to run a NeoPixel strand

Official Hardware UNO Family UNO R4 WiFi
1

I'm cutting my teeth on hardware programming and chose an Arduino Uno and NeoPixels as a starting point. The blocker that I am having is just getting the NeoPixel strandtest script to run. I tested the strand (8 pixels on a PCB) on Raspberry Pi Pico. My wiring and the MicroPython script worked there.

Attached is the Wokwi simulation for an Uno I put together to show my work.

I feel like I'm missing some fundamental step. I've worked through Adafruit's NeoPixel guide, too.

Troubleshooting I have tried:

  • Using the Adafruit recommended resistors and capacitors in the circuit.
  • Without the recommended resistors or capacitors.
  • USB-C power to the Uno, and 5v adapter to the NeoPixel
  • 5v adapter to both.
  • NeoPixels powered by Uno, Uno connected to 5v adapter.

Any thoughts/feedback are appreciated.

2

Some libraries have not yet been updated to work with the Uno R4. I am not sure about the status of the Adafruit library but FastLED has certainly been updated

See GitHub - arduino/uno-r4-library-compatibility

3

If you don't have any pressing need to use an R4, do yourself a favour and buy a R3. The R3 is a mature, well supported product with lots of libraries that work. The R4 is still in the "bleeding edge" category in my books and, while an interesting platform, using it as a learning tool is just going to make your life much more difficult than it needs to be.

4

I'm reading similar in the Adafruit forums. Thank you for the link to the library compatibility list.

5

I'll probably take that advice. I hadn't realized how "new" the R4 is. It came in a junior hardware programmers kit I bought. I figured that the R4 would be great for general stuff and should be useable with NeoPixels. Another unintended lesson from that kit.

Thank you for the feedback.

6

The drivers and libraries will be released eventually and you will be happy to have the R4. In the mean time, consider a Nano (Amazon US$4) or Tiny88 (Amazon US$2) to practice with ready-made code on the internet. Or, stick with perfecting the available R4 suite.

7

Appreciate the encouragement and advice. I hope to get the R4 and the Arduino IDE to a state that I can use the R4 as a testing platform. Code tested there I hope to copy to Nanos or Tiny88 or similar.

8

Have you tried FastLED? that library has an early porting for UNO R4

9

It is not a good idea. Uno R4, Classic Nano and Tini88 are microcontrollers from three different families.
It is unlikely that you can simply copy code tested on R4 to Nano or Tini88 without significant modifications.

1 Like
10

I did try that yesterday. Arduino IDE returned a compilation error:

"This platform isn't recognized by FastLED... yet."

The compatibility may still be under development and hasn't been added to the latest FastLED release.

11

Which version of FastLED do you have installed ?

12

Thank you. I'm still learning about the board families and how to identify the "siblings" or "offspring" in given trees.