Category: Electronics

Improving the Wanhao Duplicator i3 – Part 1

A shakeproof washer and a nut secure the M3 screw.

Yesterday I got my Winhao Duplicator i3 and when I was setting it up and adjusting the print bed I thought: “Is it supposed to be like this?” The print bed is a heated aluminum plate which is mounted on top of the Y-axis sled by four M3 screws, one in each corner. These screws… Continue reading Improving the Wanhao Duplicator i3 – Part 1

Don’t trust the datasheet!

Pinout of the 2SS52M magnetic sensor according to the March 2016 datasheet from Honeywell.

Today I wanted to use a magnetic sensor for a small project. I had three Honeywell 2SS52M sensors in my stock – a magnetoresistive switch, more sensitive than your usual Hall-effect based ones. For my project it didn’t matter, but since I had these lying around I could as well put them to some use.… Continue reading Don’t trust the datasheet!

A portable electronics bench

The briefcase now with increased breadboard area.

A couple of years ago I mounted an Atmel STK500, a couple of breadboards and a power supply in a briefcase. This allowed me to bring test circuits to my lectures and demonstrate them in the class room. Since I now have abandoned the STK500 in favor of just a USB programmer for AVR microcontrollers,… Continue reading A portable electronics bench

The humble capacitor

I just watched some videos and got inspired… Are Your Capacitors Installed Backwards? Capacitors 1965 US Air Force Training Film

ATmega328P – measuring its own supply voltage III

Timing of the internal analog-to-digital converter of an ATmega328P with a 5 V supply voltage.

After the first two parts of this series ATmega328P – measuring its own supply voltage ATmega328P – measuring its own supply voltage II where I investigated the possibility of the Atmel ATmega series microcontrollers to select the internal bandgap voltage VBG as input for the analog-to-digital converter. Using the analog supply voltage AVcc as reference… Continue reading ATmega328P – measuring its own supply voltage III

ATmega328P – measuring its own supply voltage II

A simple yet versatile testcircuit for the analod-to-digital converter.

Here is a brief follow up from yesterday’s post on the internal reference voltage VBG of the ATmega328P. I wrote a small test program where I wait for a variable delay time after switching the input multiplexer of the analog-to-digital converter to the internal bandgap reference voltage VBG. Using the AVcc of as the conversion… Continue reading ATmega328P – measuring its own supply voltage II

ATmega328P – measuring its own supply voltage

A sketch of the test circuit on a breadboard.

The trick is not new, it is utilized in the AVR transistor tester which you can buy for quite cheap money from China, and it has been discussed in internet forums for almost 10 years (see below for some links). The Atmel AVR microcontrollers feature an analog to digital converter (ADC) equipped with a multichannel… Continue reading ATmega328P – measuring its own supply voltage