Hi
as will become apparent I am relatively new to electronics so please be patient.
I have been experimenting with NodeMCU boards and a program called WLED. I have successfully connected my WS2811 12v Led's to the board using an 8amp 12dc PSU for the Led's and a buck converter set to 5v for the NodeMCU. All is well on the bench but when I connect in situ, the lights flicker randomly. I had already purchased an 8 channel signal amplifier and as the only difference between bench and situ was the length of the data wire, I thought I'd give it a go. It worked fine and all flicker has gone. But what a waste of 7 channels!
So my request is - can anyone help me with a design for a simple single channel amplifier so I can retrieve my 8 channel amp?
The amp uses HC245 chips which I can get hold of but any solution would be appreciated. I only need to amplify the signal off D4 on the NodeMCU
Thanks in advance

 

All is well on the bench but when I connect in situ, the lights flicker randomly.

I think that shouldn't be too hard to fix. But it's hard, based on just words, to understand your situation. Can you sketch out a schematic, and maybe show a few photos of your build? Experienced eyes might spot your problem straight away.

 

I think that shouldn't be too hard to fix. But it's hard, based on just words, to understand your situation. Can you sketch out a schematic, and maybe show a few photos of your build? Experienced eyes might spot your problem straight away.

Thank you for your reply wayneh. I spent most of yesterday on the net and think I have a solution! Although my NodeMCU is powered by 5V from a buck converter, it goes through a voltage regulator dropping the voltage to 3.7V, the data output on D4 is therefore only 3.7V. When my data cable is really short (10 cm) the resistance of the data wire is small and the 3.7V is just enough to be read by the WS2811 chip in the LED strip. When the data wire is long (in situ) it is about 2 m long and has a measurable resistance which drops the data voltage below what is needed for the WS2811 chip to work efficiently. I have ordered some 2 channel 'logic level shifters' that I believe will allow me to boost the data voltage from 3.7V off the NodeMCU to 5V needed for the WS2811 chips.
Does this sound about right?
In anticipation

 

Thank you for your reply wayneh. I spent most of yesterday on the net and think I have a solution! Although my NodeMCU is powered by 5V from a buck converter, it goes through a voltage regulator dropping the voltage to 3.7V, the data output on D4 is therefore only 3.7V. When my data cable is really short (10 cm) the resistance of the data wire is small and the 3.7V is just enough to be read by the WS2811 chip in the LED strip. When the data wire is long (in situ) it is about 2 m long and has a measurable resistance which drops the data voltage below what is needed for the WS2811 chip to work efficiently. I have ordered some 2 channel 'logic level shifters' that I believe will allow me to boost the data voltage from 3.7V off the NodeMCU to 5V needed for the WS2811 chips.
Does this sound about right?
In anticipation

previous post: 3.7V should actually be 3.3V...... I think?

 

previous post: 3.7V should actually be 3.3V...... I think?

All sorted thanks. How do I close this post?