LCD TFT 3.5" sometimes all multi-colour pixels upon reset

[ayates]

I have a design using the Huzzah32 ESP32 and the 3.5" LCD TFT. Arduino core, SPI to LCD, TFT_eSPI library. In general this works perfectly over multiple units. However, in one environment I have observed a number of times, where on one unit on power-up the LCD blinks then just shows all multi-coloured pixels.

I haven't yet been able to reproduce on demand, nor see what state the ESP32 might be in.

However, I am wondering if for some reason this particular LCD is not fully resetting? As the documentation indicated the LCD reset itself on power up, and this worked just fine during development, I didn't connect the reset line from the LCD to a pin on the ESP32. I will be patching that in, and including it on the next rev of the board.

But I was wondering if this multi-colour pixel issue sounds like a reset issue to folk?


Thanks,

Allan.

[dastels]

That was my first thought based on past experience.

Another approach if the MCU reset doesn't do it is to connect the display's reset to a output pin and reset the display "manually" when your code starts up.

Dave