I have this weird thing going on.
I’m relatively new to 12v WS2815 strips but I’ve had a 5v 2811 running non stop for about 4 years.
The situation.
I want to have a WS2815 as programmable accent lights on my car. I want them to come on when I hit the brake. So, obviously, I will need to engage the brake to switch states. I’m prepared for that.
Here’s the problem.
I programmed a NodeMCU to do the effect. When I turn off power (brake not engaged), it goes off. When I turn the power on (engage the brake) sometimes it will light normally, with the effect but most of the time a few LEDS light up bright white and then a single one lights red.
When I cycle power, most of the time the number of white LEDs changes and about 25% of the time it will light with the effect.
I have it set to 78 LEDS (the width of my car window) and have it set to turn on with preset #1.
I’ve tried reflashing the board and the problem still exists. What I haven’t done is set to skip LED#1.
With the setup I have, changing the GPIO isn’t simple. It would be a last resort. I have a dozen more NodeMCU controllers so I’d try swapping one of those out first.
The new test had unusual results. I verified that these are 12v strips. And I verified my output voltage is 12V so it’s not a voltage inaccuracy BUT, if I turn the voltage down to around 7V they seem to work fine. No loss in brightness.
This is a problem because, as said before, I’m using them on a car.
ESP8266 will output gibberish on GPIO2 (and some other GPIO) at boot. This will inevitably light some LEDs connected to that GPIO. You can’t do anything about it other to set boot preset that will turn LEDs on and then off.
That is just the driver for the USB to serial converter on the board. It is so you can connect it to your pc and flash the chip. It is a driver for your pc. Nothing to do with the lights.
So far GPIO3 seems to work better. It still doesn’t turn on with the preset right off the bat.
It starts amber and then fades into the preset in about a second. Then the preset takes about 3/4 second to get to the actual speed.
(Using a simple blink to test)
I haven’t tried disabling the first LED to see what that would do.
I’ll try that on my next one.
The one I’ve been working on is now installed in my car. It appears to be working “good enough” for what I wanted it to do.
One down, 19 to go.
So, what I found out about GPIO3 is that its memory can only handle 250 LEDs. OUCH!
It seems there are a lot of trade-offs. I’m glad I didn’t go through the process of modifying all my NodeMCU boards to move the signal from GPIO2-GPIO3 on the plug in power supply.
General problem solving techniques would usually be to try a solution and verify it before you spread it out to your installed base of devices (at least for me).
The only problem with 12, 13 and 14 is that they are not HW accelerated. That means that unless you use small amount of LEDs performance will suffer and/or you may see glitches in LED output.
Learning new stuff every day.
The Design I’m working with, today, only has 3 possible output pins but since it’s a work in progress, I’m able to keep modifying it.
Right now it’s designed to use output 1,2,3 whether using a single output point or a combination, assigned from the WLED.
I do want to make sure I can run, at the very least, a full LED strip (300 LEDs)
