The LEDs (WS2811 COB 24V) don’t listen to the ESP32 controller with WLED (v.0.14.1) and do whatever they want. Even if im using the solid mode the LED flashs in every color. With the use of a 470 Ohm resistor in the data line I could solve the problem, but only for 15-20cm wires, not longer but see down below the problem:
V+ from 24V supply to V+ (red cable) from LED Band
V- from 24V supply to V- (white cable) from LED Band
V- from 24V supply to GND from ESP32
5V Micro-USB to ESP32
G4 Pin from ESP32 to Data (green cable) from LED Band
With this setting my LED Band just flash between colours even though i am in “solid” mode and does whatever it wants.
Then I added a 470 ohm resistor between the data line from G4 to the LED Band. Changed like day and night and the LED Band does what it should. If I turn the brightness higher sometimes it changes the solid color to another one for a second but it’s okay.
But, it only works when the wire of the Dataline is about max. 15-20 cm. For my project it is needed that the ESP32 and the first LED of the LED Band have a distance of nearly 1m.
I know it’s not recommended, but I can’t change it in my project.
So I thought I have to boost the data signal with a level shifter. I have bought this the level shifter from the top and connected it like that:
5V output from ESP32 to VB on the level shifter
3,3 V output from the ESP32 to VA and OE on the level shifter
GND from level shifter and GND from ESP32 to the V- of the 24V Supply
V1 from the level shifter to G4 from the ESP32
V2 from the level shifter with an 470 ohm resistor to the data line from the LED Band
V+ and V- from the 24V supply to the LED Band itself
But the level shifter dosent change anything, I still have the same problem.
I have tried to change the OE from the level shifter from 3,3V to the common V- of the 24V supply, but it also dosent worked.
Where is my mistake? I think the level shifter does nothing in my case, so It has to be wired wrong or?
Try different values of the resistor. I had the same problem just like what you said ws2811 would not work even with a simple sketch then I added a simple resistor of 220 ohms I believe ( may not be exact value) but it worked fine for me. I think strips from different manufacturers may require different values depending on how the circuit is implemented on the strip.
I did tried 68 Ohm, 136 Ohm, 470 Ohm and 940 Ohm but it dosent help with the lengh Problem.
If i have everything connected and on with a short (15-20 cm) data cable it works, if i only change the data wire to an longer cable then i have the problem directly.
A data cable of 1m is not typically too long.
You could try using a dedicated ground and data pair of wires. Use something reasonably light (20 to 24AWG) and make sure you connect the ground at the levelshifter end near the chip and the ground at the strip end directly to the strip.
Also make sure your wiring is neat, tidy and as short as possible.
Don’t use removable Dupont connectors, solder your wiring.
The other possibility is to try a different type of levelshifter.
The 74AHCTxxx based devices are very simple to wire up and work well for many people.
Lastly, I would try a TxRx pair (RS485) as mentioned.
You can see details in the KB: Long data lines although this is really overkill for such a short distance.
I have bought a 74AHCT125, tomorrow it will arrive.
Today i tested a SP108e Controller and it works perfectly, even with an 1 Meter data wire. The only problem with it is, that it has his own OS on it, but it seems to be possible to flash WLED on it.
If the 74AHCT125 dont help, i will try to flash the SP108e.
Unfortunately it didn’t work either, I wired it according to the scheme here.
But when I measure the data line, nothing comes through and the LED strip no longer reacts at all.
How do you “measure the data line”?
You won’t see anything with a voltmeter measuring a datastream.
You’re missing a few pieces of the standard '125 diagram:
No floating inputs - 2OE,2A 3OE,3A 4OE,4A must be connected to something or they can pickup noise and cause grief. You can just ground those pins.
Missing 100nF (0.1uF) ceramic bypass capacitor - Needs to go near pin 14 to ground to eliminate switching noise.
You can do a static test of the chip by connecting power and leaving disconnecting data input (1A) from the chip.
Touch 1A to 5V (Hi level) and you should measure >3.5V on 1Y.
Touch 1A to ground (Lo level) and you should measure < 0.8V on 1Y.
With this one everything works perfect, even with longer data lines.
I guess it has allready “installed” a level shifter with resistors and so on on the board.
But it dont come with WLED, what I actually need for Home Assistant. I will try to flash WLED on it, I think it’s the better solution for me and the price is similar to an ESP32 with all the extra stuff that is needed.
