Couple of questions… Controller is ESP32…5v power supply for esp and 24v (400 watt) for leds.
Have PAUTIX RGB Smart IC COB LED Strip Light 20ft/6.1m,720LEDs…122 IC chips… In Wled config for length do you use 720 or 122?
Have flickering with shifter in circuit… using HiLetgo 4 Channels IIC I2C Logic Level Converter Bi-directional… Is a resistor needed? If so, what ohm? Wled shows a 100 (different shiffter) but also looking other places information up says 470… then another says anywhere between 220 and 470… then there is another saying 33 ohms (8 channel out controller with ESP32)… what is being used to calculate - not just ohms law.
Using GPIO’s 2,5,23 and 33… Should this be different?
Appreciate any advice. not sure why I’m getting flicker… worse when 2 strips are connected.
First issue to correct - I2C levelshifters are not reliable for LED data.
I would strongly suggest you use a 74AHCTxxx based device for a proper levelshifter.
The choice of a resistor is far, far less of an issue. I’d start without one.
Until you have a reliable datastream, you’ll be chasing a variety of “unknowns” in your setup.
The TXS0108’s have been problematic for many people.
A big reason that many people suggest the 74AHCTxxx devices (myself included) is that they are very basic devices that do their job well. That type of IC is mature technology and its use is well proven/understood. The other plus for me is that you only need one supply voltage (+5V).
Follow all the wiring recommendations (use a 100nF ceramic bypass cap and make sure there’s no floating inputs).
as an updated changed to a 74ACT245 (couldn’t get an AHCT)… 2 in and 2 out … is working with a 470 ohm resistor…
greatly appreciate the input everyone.
also played with the other shifters some more - and appears they will work with only 1 input and 1 output.
Personally, I’ve never needed any resistors at all (I tend to keep my data lines under 3m or I simply go with a TxRx pair). You might try with a much lower value 33-75 ohms, or even none at all.
The '245 is a good choice, gives you the option for 8 outputs which can be handy.
Just make sure you deal with all the unused inputs.
