OLED shows nothing on Wireless Stick with OTAA_OLED.ino

[Waldmensch1]

ESP32_LoRaWAN/examples/OTAA_OLED/OTAA_OLED.ino

The Example compiles fine. LoRa Sending works like a charme and data arriving in TTN. But the OLED stays dark. I have to something special to get the OLED run on wireless Stick.

Do I have to modify somewhat in the libraries? The OLED cannot be broken because it has shown something with the code from factory when I plugged in on USB first time.

• Tested the actual code from Master branch
• The Heltec ESP32 Dev Boards library v1.1.0 is loaded in Arduino
• The Heltec ESP32 Dev Boards Board 0.0.5 is loaded in Arduino Boardmanager
• The Board "Wireless Stick" is selected in Arduino Board selector.
• License code is pasted into code and all TTN IDs are set (TTN communication runs fine)
• serial output looks good:

15:30:56.554 -> confirmed uplink sending ... 15:30:57.648 -> receive data: rssi = -55, snr = 26, datarate = 5 15:31:12.465 -> confirmed uplink sending ... 15:31:13.562 -> receive data: rssi = -57, snr = 25, datarate = 5 15:31:28.396 -> confirmed uplink sending ... 15:31:29.493 -> receive data: rssi = -58, snr = 25, datarate = 5 15:31:44.489 -> confirmed uplink sending ... 15:31:45.578 -> receive data: rssi = -57, snr = 26, datarate = 5

[Waldmensch1]

I put some code in to show the pins. These looks okay and match with WirelessStick mapping here: https://resource.heltec.cn/download/Wireless_Stick/Wireless_Stick.pdf

So no clue why nothing is shown on Display. Only serial output works and the whole LoRa works as well.

case DEVICE_STATE_SEND:
{
  LoRaWAN.displaySending();
  prepareTxFrame( appPort );
  LoRaWAN.send(loraWanClass);
  deviceState = DEVICE_STATE_CYCLE;
  Serial.print("SDA_OLED: ");
  Serial.print(SDA_OLED);
  Serial.print(" SCL_OLED: ");
  Serial.print(SCL_OLED);
  Serial.print(" RST_OLED: ");
  Serial.print(RST_OLED);
  Serial.print("\n");
  break;
}

18:20:52.203 -> confirmed uplink sending ... 18:20:52.203 -> SDA_OLED: 4 SCL_OLED: 15 RST_OLED: 16 18:20:53.292 -> receive data: rssi = -60, snr = 28, datarate = 5 18:21:07.657 -> confirmed uplink sending ... 18:21:07.657 -> SDA_OLED: 4 SCL_OLED: 15 RST_OLED: 16 18:21:08.752 -> receive data: rssi = -60, snr = 22, datarate = 5

[Waldmensch1]

I tested the "Wireless Stick FactoryTest" Example in the meantime, there the Display works like a charm. So it is not broken. This Example uses the heltec.cpp library

if I change on top of ESP32_LoraWAN.cpp the Geometry this way to GEOMETRY_64_32 the display at least some illumination but only pixel. So I believe the Display integration in ESP32_LoraWAN.cpp is wrong somehow

if defined( WIFI_LoRa_32 ) || defined( WIFI_LoRa_32_V2 )

SSD1306  Display(0x3c, SDA_OLED, SCL_OLED, RST_OLED);

elif defined( Wireless_Stick )

SSD1306  Display(0x3c, SDA_OLED, SCL_OLED, RST_OLED, GEOMETRY_64_32);

endif

[grichfitz]

I also had issues with the OLED on the wireless stick I solved this by doing the following: // Setup Display pinMode(16, OUTPUT); digitalWrite(16, LOW); delay(50); digitalWrite(16, HIGH); Display.init(); Display.setFont(ArialMT_Plain_16); Display.flipScreenVertically(); Display.setTextAlignment(TEXT_ALIGN_LEFT);

Display.clear(); Display.drawString(1, 0, "Hello World"); Display.display();