Homemade Sensor Node for Home Assitant ESPHome

Nowadays, home automation becomes favour trend. Being able to monitor what goes on with your house is very interesting especially when you do it wirelessly. In case you have no idea what it is, please have a look at this Home Automation 101 article.

Each uController is a sensor node and it can connect with multiple sensors at the same time. As a beginner, one of the challenges is managing the cables between those devices. You will find yourself either stuck in the cobweb of wires or have to design a PCB of them.

In this project, I will show you homemade sensor nodes that does not require soldering or complicate components. You can kick off you project without spending too much time on preparing the hardware.

For the sake of simplicity, we will choose small footprint uController (I use ESP32-C3 super mini). We need them to fit on the mini breadboard. In terms of sensors, display...I will go with the ones that use I2C bus. You can connect a lot of I2C devices to the same uController with the same bus. You can get the per-soldered sensors and uController so you won’t have to do it yourself. I got them all from Aliexpress.

1. Ucontroller: ESP32-C3, you can get similar ones as long as it has small footprint
2. Mini breadboard
3. Breadboard jumper wires
4. Sensors and display: choose the one you need as long as they are I2C. For example: temperature and humidity (SHT31), gas sensor (SGP30), Oled display (optional)

For I2C bus, you will need 4 pins Vcc, Gnd, SCL and SDA. The first thing we need to do is to locate those pin on the uComtroller. In case of C3 mini, those pins are shown in my photo but they may be different from other seller of Aliexpress so have a look to be sure.

This node is for temperature and humidity monitor. You can use the jumper wires to connect 4 pins of the uController on the mini breadboard like the first photo. Then you can add the sensor on the spot in the second photo.

Then you can add this code into your ESPBuilder. For more details about software, please check on this tutorial

When you get the first node done and run. You can expand you node by adding more sensor in the same mini breadboard. All you have to do is extend your jumper wire connection. For example, I added the SGP30 sensor.

With the same mini breadboard you can also add an I2C Oled display.

Of course every time you add a device you will need to define it in the yaml file of your micro-controller.

Using this method, your sensor node will be well organized on a mini breadboard. No more tangle wires or cables, you can focus on the important thing, monitoring your house.

Happy making!