Supplying Power to the ESP32 Sensor Nodes

Power to the breadboard

The white breadboard can be powered using the power supply board. It has two time two pins below the board, which fit into the blue and red power rails of the breadboard. Be sure to connect the plus pin to the red rail and the minus pin to the blue rail to avoid confusion. The power supply board is powered by a DC power supply with a barrel jack connector.
On the board is a white push button, which can be used to turn the power on and off, a green LED indicates the power state.

On the top of the board is a orange jumper, which can be used to select the voltage of the power rails. By default, it is set to 5V, but it can also be used to disconnect one of the rails or set to 3.3V if needed. However, the SDS011 dust sensor requires 5V to operate, so it is recommended to keep it at 5V for this project.

Additionally, there are two pins for each voltage on top of the board to connect other hardware directly to the power supply board.

Power to the nodes

Each sensor node uses a Y-shaped wire to connect both the sensor and the ESP32 to power.
The connection points are marked with a piece of electrical tape, with a red piece indicating the positive connection and a black piece indicating the ground connection.

As jumper wires come in a lot of different colors, multiple colors are used for the actual wire. | positive | negative | | — | — | | red | yellow | | red | brown | | green | blue | | white | black | | purple | gray |

ESP32

On the ESP32, the positive wire is connected to the 5V pin, and the negative wire is connected to one of the GND pins.

Pin 16 is used for RX and pin 17 for TX when connecting to the SDS011.

SDS011

The SDS011 comes with a 7 to 5 pin connector cable. From left to right, the wires on the board are:
empty, empty, 5V, empty, GND, RX, TX
On the 5 pin adapter the wires are:
empty, 5V, GND, RX , TX

Remember, that RX and TX are crossed when connecting to another device.