I have wired everyhting like it is showen in the picture above. I have no resistor on the data line since its 3.3V anyways. Now when i press reset on the Arduino the FIRST 5 LEDs light up WHITE.
The Arduino and the LED Stripe are both wired to the same power input. One of the BTF-Lighting Power Supplies... Maybe somebody had the same issue or knows how to fix this. It really annoys me when I start it up and it lights up white...
Try a 10K resistor between the data line and ground.
Also I am surprise you don’t need a level shifter, ppl say these devices are fussy.
a7
1 Like
Think it's a generic drawing that assumes that the controller is 5V logic?
1 Like
I think it doesn’t matter, should not hurt and might work.
It might not. Straw clutch.
The OP did say 3.3 volts on the data line, the pixels are 5 volts, so.
a7
1 Like
What has that got to do with anything. You obviously have missed what that resistor is for.
- to reduce ringing (false triggers) in long data lines.
- protecting the pin and/or the first LED in case one of them is not powered up yet.
The electrolytic buffer capacitor on the strip, close to the first LED, is also missing.
It's also there for reasons you might not have thought off.
Driving a 5volt-logic LED strip from a 3.3volt-logic processor could have unexpected results.
You should have a level converter chip in between (not an I2C level converter).
Which pin of the ESP8266 is driving the strip. Some pins are not suitable.
Leo..
1 Like
Thank you very much for your quick response!
I have now succesfully created a wiring plan. I hope you can understand it.
My first question is do i still ned the Resistor in my case with the 74AHCT125? If yes maybe you can explain me short what ringing is that would be awesome. I am fairly new to Electronics so i excuse myself for not understanding that much until now. Is the electrolytic Buffer the Capacitor i have placed not at the LED Stripe but at the power supply? I have found the Capacitors always at the beginning of the Power Supply thats why i have placed it there. If i need a seperate one which would i need?
Blockquote Avoid connecting NeoPixels to a live circuit. If you simply must, always connect ground first, then +5V, then data. Disconnect in the reverse order.
I have found that on the Adafruit Website as advice my circuit is all wired up so the power will get to the microcontroller and LEDStripe almost at the same time is that an issue or does it still work like that?
Thank you very much in advance!
Phil...
Depends how long the wire is between chip and first LED.
Can't harm if you just use it.
The cap must go directly on the LED strip. It does nothing useful where you have drawn it.
The resistor must also go near the first LED.
Should also use a 100n ceramic cap between VCC and ground of the 74AHCT125, close to the chip.
1 Like
Hi there,
thank you very very much! You helped me out a lot maybe you can explain me how you calculate the Capacity of the Capacitors. And because of the Condensator before the LEDStripe the Microcontroller will turn off at first and then the LED Stripe because the Condensator is like a small "Battery". I will order the parts today and update the post here when i tried it. Hope it works!
Phil..
Do u have a software where you can create circuit diagrams easy because hand drawning are not that nice...
100n ceramic is a standard value on the supply of digital chips (every chip should have one).
The electrolytic cap will also discharge through the ESP8266, because all 5volts are connected.
The cap on the LED strip only smooths peak currents that could cause ringing.
Leo..
1 Like
Hey Wawa thank you very much ill post in the next few days my wiring with pictures. The 5V wasnt actually the problem why my LEDStripe was stuttering in the effects. I found out that i need a FastLED.delay in my programm since the esp was sending to many informations to the LED Stripe. Now i have added a FastLED.delay in my main loop and now my LEDStripe gets updated 90 times in a second. That was the perfect fit since at an rate of 120 frames per second LEDs started to randomly flash. What i also found out that the stuttering without the FastLED.delay function was starting at a LEDStripe length from 65 LEDs and started to work again at a length of 200 LEDs. This is very weird since the esp sends even more commands if the length is smaller so i dont know why my LEDStripe actually starts to stutter at a length of 65 up to 200 LEDs. Anyways the fix for it was the FastLED.delay fuction. Maybe somebody knows something why i experienced an issue like that. And the first few LEDs at PowerUp still light up WHITE and i still dont know why. really strange!
Phil
This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.