using i2c sensor with OLED

[kovir]

Hi I connected DHT31 temp & humidity sensor via i2c (using pin 21 & 22) but it won't work when OLED is initiated (display.init(); ) - I get NaN from DHT31. When I comment out display.init(); sensor works... How to use i2c with enabled OLED>?

[toddlesher]

Use the second I2C bus:

// Second I2C bus for sensors
TwoWire SensorWire = TwoWire(1);

// Bringup sensor I2C bus BEFORE OLED.
SensorWire.begin(PIN_SDA, PIN_SCL);

SDA is pin 21, SCL is pin 22.

[DaveCurnow]

Not sure about the version you are using, but I eventually managed to get my WiFi Kit 8 working with a I2C IR Temperature sensor. The trick was to bring the display up first and then the sensor. #include <Adafruit_GFX.h> #include <Adafruit_SSD1306.h> #include "Wire.h" #include <Adafruit_MLX90614.h> Adafruit_MLX90614 mlx = Adafruit_MLX90614(); #define OLED_RESET 16 Adafruit_SSD1306 display(OLED_RESET); const int Pushbutton = 13; const int LED = 12; int value = 0;

void setup() { Serial.begin(9600); Serial.println("Adafruit MLX90614 test"); pinMode (LED, OUTPUT); pinMode (Pushbutton, INPUT_PULLUP);

display.begin(SSD1306_SWITCHCAPVCC, 0x3C); // initialize with the I2C addr 0x3C (for the 128x32) display.display(); mlx.begin(); delay(1); // Clear the buffer. display.clearDisplay(); display.ssd1306_command(SSD1306_DISPLAYOFF); }

[cdoern]

did anyone ever figure this out? trying to use an mpu6050 with the heltec esp32 wifi lora