Hai all friend Is there any one use SN74CH245 IC for pixel LED circuit. I am using ESP1 for control pixel LEDs and I need to add ESP1 data out to 74HC245 and take out from that to send data to WS2812B. I am going to use large no of pixels so thats why I planed to use this IC as buffer for smoth operation. So I am new with this IC and confusing with OE pin and DIR pin how to connect I am planed to use poart A as Input and poart B as Output so can anyone help me. Is it need pullup and pulldown down resistors and how input output pins connected. Thanks
Have you checked the HC245 datasheet? Without knowing exactly how you’ve connected it (No annotated schematic), I can’t give a definitive answer on what to do with the OE\ and Dir pins.
There are other parts that could work, but I’m assuming you already have the HC245. I’m also assuming you’re using it to buffer the signals to the WS2812B LED device.
Datasheet says /OE is output enable (LOW) for isolating the A and B bus, and DIR is for direction (A bus to B bus or B bus to A bus).
is this correct I am using A bus for input
Looks like /OE is wired "enabled"... so you are half way there.
Have you tried an example from a 245 library?
I have connected DIR pin to ground some were I saw From A to B means A input and B out put then DIR pin LOW. in data sheet say DIR HIGH for that
I think I saw the video you saw, but you missed the 245 was only buffering the output of the ESP32 through the IC. Did you research the use of the IC, or do you have a carrot and are expecting to make apple pie?
yes This IC is use for pixel LED control where the large no of pixel handling for smooth operation and I have seen so Meany peoples use this buffer IC
Do you mean ESP-01?
If you are using ESP-01 then 74HC245 may not help you in any way with smoothly controlling a large number of LEDs. This chip may not reliably shift signal levels from 3.3V to 5V. For that you need 74HCT245. It also may not help you update large numbers of LEDs more quickly because ESP-01 does not have 8 pins to allow 8 separate strips to be updated simultaneously.
Use their code.
I don't use all input out put I use only one Data input and one data out put pixel length is more around 5000 so that why I am going to use this IC. is this SN74HC245 not support for this ?
This chip will probably not help you. I gave the reasons in my last post. If you cannot understand I will try to explain using different words.
ok dear let me know more clear way please explain
74HC series chips are not designed for logic level translation from 3.3V input to 5V output. They will provide the correct 5V signal for the LEDs, but they may not receive the 3.3V signal from the ESP reliably.
74HCT series chips are designed slightly differently. They will receive the 3.3V signal correctly from the ESP and provide the correct 5V output signal for the LEDs.
If you cannot get 74HCT chips, then some 74HC series chips have a better chance of working correctly than others. For example 74HC14. This chip has Schmitt Trigger inputs which should have a good chance of reading a 3.3V input signal correctly. I have used these chips between ESP and WS2812 strips in the past and they have always worked for me. But 74HCT is the better choice if you can get them.
Thanks for your clarification dear.
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