I'm trying to drive a strip of NeoPixels/WS2812b using an ESP8266 controller. To do so I'm using an external power supply (5V/10A effectively more like 5.6V) and a 74HC245 to shift the 3.3V data line from the ESP to the 5V needed by the strip.
I can't get the strip to work even when driving only few LEDs. I either get all LEDs turned on on full bright white and the first LED flickering (with DIR pin of the '245 attached to 5V) or some incoherent colors on the LEDs (with DIR not connected).
Here is my wiring:
- Power supply 5V -> ESP Vin, NeoPixels Vcc, '245 Vcc and DIR
- Power supply GND -> ESP GND, Neopixels GND, '245 GND and OE
- ESP8266 D0 -> '245 A1 -> '245 B1 -> NeoPixels Din
The 74HC245 seems to work properly as if I use an Arduino to drive the strip on 3.3V, the chip properly shift the data line down from 5V to 3.3V and the strip is behaving properly. And a test with continuous 3.3V as input gives a 5.1V output
What am I missing here ?