Implementation

Let's discuss the hardware first. The following Fritzing diagram shows the connections between ESP32 and other hardware components:

Figure 5.2 – Fritzing diagram of the project

The interesting point here is the Inter-Integrated Circuit (I2C) connections. I2C is a bus, so we can connect multiple devices on the same bus, as long as they have different bus addresses. Therefore, we connect BME280 and TSL2561 to the same pins of ESP32, GPIO21 and GPIO22. The OLED screen is also an I2C device, but its driver uses the second I2C channel of ESP32, so it is a good idea to connect the OLED screen to other GPIO pins to avoid any configuration conflicts.

Before delving into the code, we need to update the configuration files. Let's start with platformio.ini, as follows:

[env:az-delivery-devkit-v4]
platform = espressif32
board = az-delivery-devkit-v4
framework = espidf
monitor_speed = 115200
lib_extra_dirs =
   ...