Multiple I2C Devices using ESP32

 Hello, Dear Reader!

In today's article, I will be showing how to setup multiple devices with I2C communication protocol using ESP32 development board. It requires knowledge about I2C so make sure to find some information about the communication protocol.

I2C Communication Protocol

I2C (Inter-Integrated Circuit) is one of the serial communication protocol beside SPI and UART. It is a two line communication between modules which using SDA (Serial Data Line) and SCL (Serial Clock Line). It uses 2 pin which are GPIO 21 (SDA) and GPIO 22 (SCL) in ESP32. Even with only 2 pins, it can control 2 or more devices as long as the devices doesn't have same address.

STEP 1: Required Hardware and Software

1. ESP32 Development Board,
2. PC (with Arduino IDE),
3. OLED display (I2C version),
4. BMP280 sensor,
5. Jumper wires,
6. Breadboard

I will be using BMP280 and OLED display for both I2C devices. They have different address (0x3C for OLED and 0x76 or 0x77 for BMP280) so both devices can be used together.

STEP 2: Assembling the Circuit

BMP280 have 6 pins but only 4 pins will be used. Those are SDA (GPIO 21), SCL (GPIO 22), VCC (3v3), and GND (GND). The OLED also have 4 pins respectively. The draw of the circuit is shown below.

STEP 3: Source Code

Before making the source code, there are few libraries that need to be installed. Go to Sketch > Include Libraries > Manage Libraries and search these libraries and install them. The libraries are "Adafruit BMP280 Library", "Adafruit GFX Library", and "Adafruit SSD1306".

Once all the libraries are installed, build the source code like as shown below.
We initiate the source code by including all the libraries we need, make sure to include Wire.h for I2C devices. Then define the screen width and height for the OLED. This OLED have 0x3C address and OLED reset for -1 (using multiple devices).

















For the setup, begin the display and the bmp. Check if both are successfully initialized.
























For the loop, clear the display of the OLED (for each loop so it can display new one). Then initiate the value of each parameter by using BMP reading function. Then set the display settings as shown above. Make sure to display all of it by using "display.display()" function. Delay the loop for 2000 ms.

STEP 3: Testing

After the code is done, verify and upload the code into ESP32. The code will successfully uploaded when there are the reading on the OLED display as shown in video below.


Comments

Post a Comment

Popular posts from this blog

Programming "Blinking Internal LED" on ESP32 using Arduino IDE

Image
 Hello everyone! This article contains step-by-step how to program on ESP32 using Arduino IDE. The example below will show the simplest program for ESP32, which is making it's internal LED blink with interval timing. STEP 1: Required Hardwares 1. ESP32 I am going to use ESP32 Devkit V1 with 30 pins . 2. PC To develop the code and power source. 3. Micro USB Cable ESP32 uses micro USB cable to connect to it's power source and/or source code 4. Breadboard (optional) I use breadboard to ensure ESP32's pin safety STEP 2: Required Softwares 1. Installing Arduino IDE, you can download it from:  https://www.arduino.cc/en/software 2. Installing the correct board you are using by going to File > Preferences. Insert this URL into "Additional Boards Manager URLs":  https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json 3. Go to Tools > Board > Boards Manager and then search and install esp32 module. Thereafter, choose which board ...
Read more

"Built-in Touch, Hall-Effect, and Temperature Sensor" on ESP32 using Arduino

Image
 Bonjour...! Today's article will show how to use 3 built-in sensors in ESP32. Those 3 sensors are touch sensor, hall effect sensor, and temperature sensor. In case you don't know, the temperature sensor in ESP32 only detect the internal temperature of itself and not its external. Without further ado, let's get straight into it! Required Hardware and Software ESP32 Development Board PC with Arduino IDE Micro USB Cable Mini LED Lamp For output indicator Resistor 330 Ohm resistance Male-to-male Jumper Cable Magnet For testing hall-effect sensor Breadboard  (Optional) Touch Sensor STEP 1: Assembling the Circuit Since not all pin in ESP32 can read touch input, make sure to use pin that accept touch input. For guideline, here is ESP32 DEVKIT V1 with 30 pins. Source: randomnerdtutorials.com The circuit is not complex, I just connect GPIO4 to a jumper cable as a touch input. Since there are no output indicator, I will be using serial monitor. STEP 2: The Source Code For the source...
Read more