• Petus
• June 12 2017
• ESP32, ESP8266, NodeMCU, Wemos ...
• 7646 Reads
• 0 Comments

Other article about ESP32. We again connect ESP32 to temperature/humidity sensor Si7021 (HTU21), but today we also connect OLED where will be showed data from sensor. The OLED has 128x64px resolution and communication bus is I2C as well as Si7021.

Thank dfrobot.com for ESP32.
I thank designer of SunDuino ESP32 board.

Other parts with ESP32:
ESP32 and Arduino IDE
ESP32, SunDuino and temperature/humidity sensor Si7021 (HTU21)
ESP32, SunDuino - temperature/humidity Si7021 sensor and OLED 128x64px (I2C)

I can choose what bus I will use, because my OLED display has SPI and I2C bus as well.
If you have OLED display with I2C you have to know what is OLED address. In my case, the address of OLED is 0x3C
The arduino library for OLED is on adafruit.
The arduino library for Si7021 is available on https://learn.sparkfun.com/tutorials/si7021-humidity-and-temperature-sensor-hookup-guide.

Connecting of Si7021 sensor, OLED with SunDuino ESP32 is easy .
You have to connect 3V3, GND, SDA of Si7021, OLED to SDA of ESP32 (21 pin) and SCL to SCL of ESP32 (22 pin).



OLED display needs RESET pin, the RESET pin of OLED is connected to 19th pin of SunDuino ESP32.

The code is available on https://github.com/petus/ESP32_SunDuino_Si7021_OLED_128x64px

Working ESP32, Si7021 and OLED.