Wolles Elektronikkiste

TVOC and eCO2 Sensors

Using the CCS811 and SGP30 as examples, I explain how metal oxide-based TVOC and eCO2 sensors work, how to drive them with libraries, and how reliable they are compared to NDIR CO2 sensors.

MH-Z14 and MH-Z19 CO2 Sensors

With CO2 sensors of the MH-Z14 and MH-Z19 series you can monitor the indoor air quality. I show how you how to control the sensors and I check their accuracy.

How to use the I2C interfaces of the ESP32

I will show you how to use the two I2C interfaces of the ESP32 and which requirements libraries of I2C components must have for this.

TCA9548A – I2C Multiplexer

I show you how to use up to eight I2C components with the same address with the I2C multiplexer TCA9548A. Alternatively, you can use MOSFETs as well for this purpose.

MPU9250 – 9-Axis Sensor Module – Part 2

This is part 2 of my article about the 9-axis sensor MPU9250 and my related library MPU9250_WE. I will explain how to measure angles and how to use interrupts, the cycle mode and FIFO.

MPU9250 – 9-Axis Sensor Module – Part 1

The MPU9250 is an accelerometer, gyroscope, magnetometer and thermometer. I present its technical characteristics and give an introduction to my library.

HC-12 Radio Module

The HC-12 radio module is easy to handle and has a long range. I’ll show you how it works, how you make settings, and how you use it legally compliant (in Germany).

DCF77 – Radio Controlled Clock

Here you will learn what the DCF77 radio clock signal is, how to receive it, how to evaluate it and how to use it optimally together with the library RTCLib.

DS3231 – Real-time clock

In this article I will present the features of the real-time clock (RTC) DS3231 and how you can use it with the RTCLib library.

ADXL345 – The Universal Accelerometer – Part 2

In the second part of my article about the ADXL345 and my library I go into Activity/Inactivity, Single and Double Taps and FIFO.

Die wunderbare Welt der Elektronik

Using LoRa with the EByte E220, E22 and E32 series

Character Arrays vs. Strings

Using FreeRTOS with ESP32 and Arduino

Arduino Nano Every – a deep dive