I’m having an issue with a stereo VU meter build that is driving me nuts. Maybe someone knows offhand what it is, because otherwise my only option is to start over and build everything again from scratch.
When I use a single LED strip to run a solo VU meter, everything works great, but as soon as I connect a data line from arduino to the second LED strip in parallel to the first, the push button stops working. Other than the mode-switch push button, the LED strips appear to work fine.
I can’t for the life of me figure out why this would happen since the push button and LED strips are seemingly unrelated, other than the fact they are both connected to digital pins on the arduino mega. Any ideas what might be causing this?
I’m using cine-lights VU meter code (combines FastLED and Neopixel libraries), and have the typical wiring set up with a momentary push button to switch modes on the LED strip(s). I’ve tried switching the input pins around, different code using same hardware setup, and problem is the same. I have also tried running the two parallel LED strips from the same digital pin and separate digital pins, and the issue is the same. At this point, I’m wondering if there is something wrong with the arduino controller itself? The only thing I can come up with is to break everything down and build this up simply testing every step as I go, but hoping not to have to go that route.
How many pixels in each strip?
How is everything powered?
Can you share the code? Or a simplified version that still shows the problem?
What does “typical wiring set up” with the button look like? Schematic?
I’m using a pull up wiring for a momentary push button (so goes to 1 when not pressed, 0 when pressed)
The odd thing is that the button works perfectly with the exact same code if I just unplug the second LED strip (so there is one digital out that is sending data nowhere), then as soon as connect the arduino pin to the second strip, the button doesn’t work. This problem occurs regardless of whether I connect the second LED strip to a different pin (as the code is written), or to the same pin as the first LED strip (which seems to work fine from the perspective of getting the data to the LEDS).
It seems almost as if there is some hardware/wiring issue between digital pins, but you’d think that could be fixed by changing the pins for the strips and/or push button, but it doesn’t. The only thing I didn’t test was if somehow the entire digital output section has something wrong with it, in which case I guess I’d just need a new Arduino.
I’ve been mulling this over and I’m thinking the next thing to try might be isolating power to the LED strips and power to the Arduino and all the components. Right now, the power runs in parallel to the two LED strips, and then from one of the LED strips to the Arduino. I’m somewhat taking a stab in the dark, but maybe I should try powering the Arduino, button, and mic from the serial port, and not running the power from the LED strip to the Arduino and components (so the only wiring between the Arduino and the LED strips is the two data lines). Thoughts on whether this is worth a shot?
You shouldn’t need to rebuild everything over from scratch to do some basic tests. Have you done a super simple test without a button and the audio stuff to confirm you can run both strips correctly? Grab the FastLED example Cylon or FirstLight and add a second strip to the code example.
After that’s working then add the button to your test to do something simple like pick a new random color to display. Always good to confirm the basics are working first.
@marmil yes, thats what I did, and it works now. I soldered power distribution for the LED strips onto a proto board and powered the button and arduino from usb (connecting all to common ground), and now it works fine. No idea why that made a difference, but Ill take it. (This is a graduation gift for an inbound college freshman) missing/deleted image from Google+