WiFi Kit32(v3) OLEDs broken on two boards

#1

I bought a WiFi Kit32(v3) from Amazon.de. and after getting a lot of help from this forum I got the OLED and a second i2c bus working and implemented a lot of exciting sketches. The suddenly the top half of the OLED started to display with pixels missing. I assumed I had handled the board too roughly and so ordered another one to continue my experimentation. The second board worked perfectly after I included a restart for the OLED in all the sketches, this wasn’t necessary with my first board. Then suddenly the OLED started displaying the same fault as my first one, ie pixels missing on the top half of the screen. The bottom half of the screen displays perfectly on both boards.

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This happens with my sketches and with the OLED examples. What is the cause of this fault? Here is a picture, zoom in to see the problem.

#2

Try an empty sketch devoid of anything other than a rectangle that fills the screen.

If that’s OK, we can then debug from there.

#3

I have just noticed a crack in the glass on the lower right hand side of the new OLED, maybe this is the cause of the problem. Here is the sketch you asked for and below it the result on the OLED:

#include <Wire.h>
#include <U8g2lib.h>

#define Vext 36        // Correct Vext control pin for Heltec WiFi Kit 32 V3
#define OLED_RESET 21  // Reset pin for the OLED

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/U8X8_PIN_NONE, /* clock=*/18, /* data=*/17);

void setup() {
  // Initialize Wire for OLED on default Heltec pins (17,18)
  Wire.begin(17, 18);
  //Reset OLED
  pinMode(OLED_RESET, OUTPUT);
  digitalWrite(OLED_RESET, LOW);
  delay(50);  // Wait for OLED to fully power down
  digitalWrite(OLED_RESET, HIGH);
  delay(50);  // Give time to initialize

  // Enable OLED Power
  pinMode(Vext, OUTPUT);
  digitalWrite(Vext, LOW);  // Turn on power
  delay(100);

  // Initialize display
  u8g2.begin();
  u8g2.clearBuffer();

  // Draw a filled rectangle that covers the entire screen
  u8g2.drawBox(0, 0, 128, 64);

  u8g2.sendBuffer();
}

void loop() {
  // Nothing needed in loop
}

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#4

Not really, just suggested you try one, but :man_shrugging:

What is your assessment of the screen - it’s hard to tell if the bottom half has a reflection on it. But it does seem that the top half looks OK. If they arrived damaged then Amazon is pretty good at handling returns.

#5

Actually the top half is missing lines and the bottom half is good. Now that I’ve noticed the crack on the OLED I am pretty sure that is the cause, everything was fine one day and the next day it was kaputt. I will invest in a third and be very careful with it :wink: Return is a bit of an issue as they arrive without the pins soldered in.

#6

I’d say not - it’s normal to put the pins on a dev board as a matter of course - you may have coded all sorts of things on the first day of use and only try the screen out the next day.

That and Amazon don’t care about the details, as long as you don’t have a track record of being an idiot about returns, they just let you. All they do is extract their revenge on the supplier - I know, I’ve been one!