In this short tutorial, I will explain step by step, how you can build a solid carbohydrate source. You will find the bill of materials and all required tools. I will use SI units to simplify all measurements. This is...

Assume, while digging out an ancient site from 450 AD, you found a mysterious stone with a digital display. Your analysis finds five inputs for five segments (a–e) and six outputs (1–6). It seems to be a classic multiplexed display....

The shown logic circuit performs a well known function; can you discover what it is? The circuit was not optimised for functionality, but to create a symmetric artwork. If you need to know the meaning of the used logic gate...

The shown logic circuit performs a handy function; can you discover what it is? The circuit was not optimised for functionality, but to create a nice artwork and interesting puzzle. If you need to know the meaning of the used...

What kind of logic circuit do you see here? This logic circuit was optimised for symmetry and art. Can you see which function is implemented in this circuit? You find more about logic gates and how they work on this...

Older people often have troubles opening plastic bottles. Also, people with gout or other disabilities lack the required strength to turn the small caps independently. The reason is the small diameter of the caps, which requires a strong grip with...

The Raspberry Pi RP2040 chip is a remarkable microcontroller. The programmable IO block (PIO) is only one many great features of this chip. In this post, I show you a method how utilise PIO, to capture the speed of an...

I got many requests to add split storage boxes to my system. Reasons were to print huge boxes and printing boxes on small printer beds. In the past few days, I released an update to my storage boxes system, introducing...

When I wrote part 3 of the pet feeder series, I did not expect the light transmission issues of this part. Now, I have two solutions with new revisions of the part. Solution 1: Epoxy Filled Slots This is the...

To solve the problem with light inference, I tested five different revisions of the turntable platform. For each revision, I recorded the sensor values and compared them to find the best solution. Visual Comparison Revision A is the original with...

The seventh part of this series is all about the sensor board. It hosts the position sensor and four fill sensors. Speaking of sensors sounds complex, but these are just pairs of IR-LEDs and phototransistors. All design files for the...

As you read in my last post about the pet-feeding device project, there was an issue with the fill sensors. The lines from the 3d-print transferred the light directly to the sensor and made a useful measurement impossible. One of...

First, I’d like to thank you very much for reading this, 😄 because it means you are already a great supporter of my work. On my blog, you saw beautiful photos of electronic boards, got detailed instructions on how to...

While testing the sensor panel, I ran into unexpected problems, requiring a small redesign. First, let me explain the simple working principle of the fill sensor circuit and what I tested so far. The Circuit The circuit for the fill...

In this short update, I will talk about the improved stepper driver for the pet-feeder device. While working on the sensor board, to see if the fill sensors work as expected, it also involved using the stepper motor. Here, I...

Ordering a board with perfect spaced pads to use an SMD connector takes a few days of patience unless you live near a PCB prototyping facility. With striped prototyping boards, you can stick a MircoMaTch or similar connector into your...

I worked on testing the sensor board. The first tests I did were about the position sensor. Recap Let me recap the design of the position sensor in the device: The turntable has five position slots, marked red in the...

I mentioned in one of my posts how to assemble the MicroMaTch connectors using a hammer, but never explained the rather simple method in detail. So I made a short video, explaining the exact technique I use. If you have...

A short update about the progress with the sensor panel and photos of the final input panel board. I assembled the new boards and are testing the sensors. As soon as all tests are done, and I am happy with...

When I migrated several servers into a new server rack, I put my Arduino Uno based fan controller into a new enclosure. Not a great solution, but good recycling of this existing project and way better than the built-in, on/off...

For the pet feeding device, I ordered boards from OSHpark with the “After Dark” style. This colour combination of the black substrate with the copper and transparent solder mask is just beautiful. I made this post just in case you...

I created a new tool to easily convert bitmaps into code for MicroPython. This first version is just a start, creating a framework where I can add additional converters. If you have any questions, missed information, or simply want to...

This design is not for everyone. 😅 A decorative and modular, but quite massive box. Built from 3d-printed parts, 5mm plywood panels and plenty 3x10mm wood screws. The instructions in this post show a basic box with the inner dimensions...

The sixth part of this series is all about the input panel. We will talk about the layout of the front panel, the rotary encoder as the main component and I will explain my example circuit and board. As usual,...

In order to test the input panel, I had to connect the 14 lines to the test setup on a breadboard. Just using a pin header was too flimsy for me, because I often reuse these test connectors on different...