OLED FEATHERWING DISPLAY TEENSY 3.2 ISSUE

[Mach33Team]

Hi everyone,

Using my teensy 3.2 microcontroller with the featherwing adapter, I was able to connect to the "128x64 Monochrome OLED Featherwing SH1107". I programmed the OLED_Featherwing arduino example sketch which ill paste in this post. It was working perfectly fine when plugged into the USB port on my computer but, when I unplugged the USB and powered it with an external power supply, the display was no longer functioning. I checked all the pins and the OLED screen and it is getting the correct voltage so its not a power issue. Its strange, as soon as I plug in the microUSB the screen pops on and starts working. I also noticed that if I plug the USB in and arduino is not open on my computer the screen wont turn on. Its like the teensy needs to be communicating with the arduino IDE for the screen to function correctly.


"
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SH110X.h>

Adafruit_SH110X display = Adafruit_SH110X(64, 128, &Wire);

// OLED FeatherWing buttons map to different pins depending on board:
#if defined(ESP8266)
#define BUTTON_A 0
#define BUTTON_B 16
#define BUTTON_C 2
#elif defined(ESP32)
#define BUTTON_A 15
#define BUTTON_B 32
#define BUTTON_C 14
#elif defined(ARDUINO_STM32_FEATHER)
#define BUTTON_A PA15
#define BUTTON_B PC7
#define BUTTON_C PC5
#elif defined(TEENSYDUINO)
#define BUTTON_A 4
#define BUTTON_B 3
#define BUTTON_C 8
#elif defined(ARDUINO_NRF52832_FEATHER)
#define BUTTON_A 31
#define BUTTON_B 30
#define BUTTON_C 27
#else // 32u4, M0, M4, nrf52840 and 328p
#define BUTTON_A 9
#define BUTTON_B 6
#define BUTTON_C 5
#endif

void setup() {
Serial.begin(115200);

Serial.println("128x64 OLED FeatherWing test");
display.begin(0x3C, true); // Address 0x3C default

Serial.println("OLED begun");

// Show image buffer on the display hardware.
// Since the buffer is intialized with an Adafruit splashscreen
// internally, this will display the splashscreen.
display.display();
delay(1000);

// Clear the buffer.
display.clearDisplay();
display.display();

display.setRotation(1);
Serial.println("Button test");

pinMode(BUTTON_A, INPUT_PULLUP);
pinMode(BUTTON_B, INPUT_PULLUP);
pinMode(BUTTON_C, INPUT_PULLUP);

// text display tests
display.setTextSize(1);
display.setTextColor(SH110X_WHITE);
display.setCursor(0,0);
display.print("Connecting to SSID\n'adafruit':");
display.print("connected!");
display.println("IP: 10.0.1.23");
display.println("Sending val #0");
display.display(); // actually display all of the above
}

void loop() {
if(!digitalRead(BUTTON_A)) display.print("A");
if(!digitalRead(BUTTON_B)) display.print("B");
if(!digitalRead(BUTTON_C)) display.print("C");
delay(10);
yield();
display.display();
}

"

[Mach33Team]

Unfortunately, the teensy feather adapter causes a short when the RST or Program pin of the adapter gets connected to the the reset button on the screen. For people with this problem, do not connect the PRGM Pin from the teensy feather adapter to the RST Pin on the SH1107 Screen. This will fix your problems.