LED strip not working -- directly connected to RIO PWM

I’ve been trying to get these LEDs to work directly into the PWM slot on the RIO: https://www.amazon.com/gp/product/B088BB8WTZ/ref=ox_sc_act_title_1?smid=A35UAT07QG3EC6&th=1. I have no idea why it’s not working. We’re thinking of just trying another strip but any advice would be much appreciated!

Day 1 (didn’t work): Tried, didn’t work. Setup: RIO PWM to LEDs (made sure the right PWM wires connected to the right spots on the LED strip), external power from PDH via 12V to 5V stepdown converter. The 1st LED receives voltage according to multimeter. Sometimes the other LEDs don’t receive power, but sometimes they do. Sometimes it’s under 1V but normally it’s 5V. Also, the first 2 LEDs were shorting out b/c there was some metal dust or something inside of them (manufacturing issue?), so we cut those LEDs off.

Day 2 (tested w/ Arduino; worked but weird): I tested it w/ Arduino Uno + it worked. It didn’t work until I tried connecting the signal wire with one of the other ones but now it works without needing to be shorted. The presence of a GND wire seems to be unnecessary as long as the signal wire is attached (but it kinda helps as a failsafe). Also there was a significant voltage drop between consecutive LEDs. W/o the Arduino, the lights only turn on by connecting + to VCC and - to signal. The wiring we tested w/ the RIO was correct so maybe there’s a coding issue or maybe we need to try shorting the signal wire.

Day 3 (still doesn’t work with RIO): Same setup as Day 1. Tried multiple PWM ports on the RIO. Tried different sections of the LED strip. Tried with additional voltage and without it. All wires were receiving voltage either way. Signal wire voltage was constant when it was receiving voltage. For a little bit, some LEDs after the first one were not receiving voltage. Sometimes, the none were receiving voltage somehow even though the wires leading up to the . For about a minute, the 5V and Signal wire had continuity even though no metal was touching other metal (100% sure). I powered a section of the LED strip from the 2nd LED onwards (alligator clips for GND and VCC, ammeter in multimeter for signal wire), then the 1st LED exploded but nothing happened to the other ones. I tried powering the LED strip segment from the other end but nothing happened.

Code based on this: Addressable LEDs — FIRST Robotics Competition documentation

Currently planning to buy new LEDs and see if those work; else maybe use an Arduino on the robot.

How long is the strip you’re connecting?

The RIO will have trouble powering a long strip on its own. You’ll want to only get signal from the RIO and power from another source.

We also had no luck with those. We also tried a Rev blinkin. No lights no matter what we tried. We gave up on them. We are going to get some from AndyMark instead.

I tried using another 5V power source and I also tried cutting off a portion of the strip that was 3 LEDs long and another that was 1 LED long but nothing lit up.

Silly question, but you’re going into the correct side for the data, right? The data is directional, so for each LED one side is input, and one side is output.

As for power, all the LED’s should always have power. If they don’t, that means something is wrong with the strip.

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Yes, I tried the output side as a last resort but otherwise I’ve been using the input side. Normally all of the LEDs have power, but sometimes there’s a steep dropoff between consecutive LEDs (~5.5V on the first LED and ~0.5-0.7V on the next one). Occasionally only the 1st LED receives power that’s detectable with a multimeter or none of the LEDs receive power.

Despite this, the strip works when I connect it to an Arduino, so I’m not sure if it’s an issue with the strip or if it has something to do with the RIO.

The RIO gives off 6V; could that be an issue, as the strip is supposed to be used with 5V? For the additional power source (5V), I used a 10A breaker. The voltage that the multimeter reads is normally ~5.5V for the 1st LED. (I’m not sure if that would be an issue though because, when connected to the RIO, none of the LEDs emitted any light, visibly burned out, or noticeably heated up.)

Have you checked to see if your LED strip is shorting to your frame?

The strip you linked is a bare metal LED strip with limited/no real insulation on the back. Depending on how you have these mounted to the robot, you could have problems.

If you can post some pictures of your setup, that might help diagnose the issue.

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