Electronics

Fast Fourier transform (FFT) is an analysis method that let's you dissect complex waveforms and determine out of which frequencies they were composed. This function is often present on an oscilloscope and in this blog I will show a basic application of it.

Electrolytic capacitors are known for their terrible accuracy. Just by reading the value on the package is often not enough to know their true capacitance. In this blog I will show how to measure the real value by using a scope.

If you want to save your valuable space and don’t want to put a real Xmas tree in your room, there is always an option to make one out of PCB and LEDs and during the process learn something about electronics.

In addition to the WeMos battery powered temperature server, it would be nice to know what the remaining level of the battery is, so we can recharge it in time. This is easily done using a voltage divider circuit and the analog input on the WeMos D1 mini module.

WeMos D1 mini is an ESP8266 based board that can be programmed with Arduino IDE. In this blog I will describe how to make a simple WiFi based server that is being powered by a Li-Po battery and shows temperature and humidity inside your browser window.

ESP8266 is Wi-Fi microchip which can be programmed just like a normal Arduino board. For that purpose some additional software needs to be installed inside the Arduino IDE.

Browsing though Chinese online webshops, I came across a DVB-T+DAB+FM USB dongle that claimed to be modded into a SDR (Software Defined Radio). The price was under 10 euros, so I decided to give it a try. After some tryouts I managed to get it working.

Blink LED is a Hello World! application for micro-controllers. If you manage to get it running, you can assume that you are all setup and ready for further developments on your board. In this blog item I will cover how to do that on a STM32F407 Discovery board.

A while back I have assembled this bench power supply kit, which I received as a gift from my friend Eric. The kit was published in a Dutch electronics forum (Circuits online) as PCB Lab voeding. It was time to create a casing for it as it was just lying around in my drawer and was not really being used.

18650 batteries are known for it's high energy density, but this comes at a price. In order to protect the battery from overcharging or over-discharging a number of ICs need to be used. Luckily these charge and protector circuit boards are readily available for sale in all shapes and sizes. In this blog post I am going to build a charger that uses such a circuit.

Not only the charger can use protection circuitry, but also the battery itself. When buying the batteries make sure that they are protected. I have bought mine in a Chinese online webshop.