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In the previous article, I introduced the design of a board for a low-cost robotics kit. After conducting several tests, I realized that the arrangement of the ESP32 microcontroller wasn't the most convenient, and furthermore, there was an issue with power supply, which wasn't sufficient to drive the motors, servo, and use the sensors. I needed to modify the design to change the position of the MCU and introduce separate power for the servos, leaving the L298N motor controller in charge of providing power to the rest of the components. I started to work on this, but at the same time, an idea crossed my mind. What if this time I made it fit into a structure built with Lego?
Read more: Robotics PCB redesigned to be compatible with Lego
A few months ago, I decided to purchase a robotics kit to program it with the kids. I chose a widely used model that can even be self-assembled from an acrylic sheet or a similar material. The idea was to use it with an ESP32, as that's what I usually use (along with ESP8266 and lately Raspberry Pi Pico), and program it using Arduinoblocks since it offers programming identical to Scratch, which is great for young ones to experiment and learn.
Following the resolution of certain power source challenges stemming from the batteries initially employed, I am happy to say that my external solar-powered weather station has been successfully restored to full functionality. This particular (MeteoHome based) weather station is equipped with a DHT22 sensor to get both temperature and humidity levels. Additionally, it features a BMP180 sensor, dedicated to monitoring atmospheric pressure with quite good accuracy.
During this summer vacation, I dedicated my time to upgrading my home automation server running Home Assistant. I swapped out my trusty SolidRun Cubox-i for a new Beelink mini PC. As I got more involved, I found myself diving back into the development of MeteoHome, making changes, and brewing up new ideas to enhance it.
After reading this article (ES) I started to think about creating my own sensor board. I searched which sensor to use and the SGP30 seemed a good option to me. Then, I did a few tests, I modified the code of another project and then I designed a PCB and later on I built two prototypes which are currently working in my house. The device uses a mqtt queue to send data to an IoT gateway (a minipc running Home Assistant in my case). In addition to that, there are three LEDs to show what is the current state of the air based on CO2 PPMs:
- Green light is shown if there are less than 600 PPM of CO2.
- Yellow light if there are between 600 and 800 PPM.
- Red when the CO2 is greater than 800.
The source code and the PCB design (made in Kicad) can be found here. In January, the project was certified by as open source hardware by the OSHWA