Help with I2C -> freeze/Brauche hife mit dem I2C bus da dieser einfriert

Hello,
I have a problem with the I2C bus …

Before I am from Germany so I have no problem to write German, since the forum but mostly of English users lives I write in the English first :slight_smile:

I have several Arduino Nano’s which each control an LED band. The LEDs are WS2812B where it is important that the data is sent without delay. All Arduino’s with their LED bands are connected as slave to A4 and A5 (the master course also with A4 and A5) and expect an integer value to start an appropriate animation. My problem is that the master Arduino Nono suspends while sending. To be more precise with the command “Wire.endTransmission ();”. If I press the Serial Monitor an animation start and then shortly after the reset button presses the addressed slave the animation.
For an animation but synonymous without the reset - when I send the int 255.

What is not so good is the distance from the bus relatively long is 25 to 30 meters in total. But the data also come fully to the slave …

I hope someone can help me because I am unfortunately at the end of my knowledge …

Hello Nils,

as you may already have read somewhere, connecting devices on the I2C bus with long wires is problematic. Probably due to the large capacitance on the bus.

My suggestion to you, try to control the LED bands with a very short wire, like 30 cm. Just for testing, in case your problem lie somewhere else.

If it does work, then you'll know, that your wires are too long.

Also, try keeping the wires with the SDA and the SCL signals away from each other. This helps to avoid cross-talk.

Hope that helps! :slight_smile: