Waveshare 1.3" OLED display not working

[testudor]

For some reason my 1.3" OLED display from Waveshare did not work out of the box. I managed to make it work by resetting the display before initializing. I added this:

  pinMode(D3, OUTPUT);
  digitalWrite(D3, HIGH);
  delay(1);
  digitalWrite(D3, LOW);
  delay(10);
  digitalWrite(D3, HIGH);

before display.init(); in the setup function. (D3 is connected to the OLED's reset pin)

[wabbitguy]

Isn't the WaveShare 1.3" OLED an SPI device? There's no reset pin on an I2C OLED.

[testudor]

It is configured for SPI by default, but you can switch it to I2C by soldering the jumpers on the bottom side. Most other SSD1106 displays do not have the reset pin exposed. I think they just have it connected to ground with a capacitor and to VDD with a pullup resistor.

[wabbitguy]

You'd think Waveshare would document that little tidbit in their data manual but apart from listing it in their table on the first page, it's absent in the I2C description. Thus, five wire I2C.

Good catch though because it's anything but obvious.

[soundylinz]

Original connection:

SDA -> D2 SCL -> D5 VCC -> 5 V + GND -> GND-

My connection:

SDA -> D2 SCL -> D1 <<<<<<-------- VCC -> 5 V + GND -> GND-

I found out because an I2C scanner couldn't find a device. That's why I tried around.

I've used this I2C scanner: http://www.esp8266learning.com/i2c-scanner.php

[Qrome]

@soundylinz -- depends on how you wire it. If you wire to D5 then use D5 -- if you wire to D1 then use it.

[jolo1581]

The RES Pin must be set to 3.3V (high)