Below is an (incomplete) overview of what keeps me busy. For some projects I take the trouble to make a project page with more detailed descriptions and a YouTube video.
In a previous project I had projected so-called hypocycloids using a semiconductor laser and two rotating mirrors. These curves were determined by the circular motion along the circumference of another circle.
If we however do not rotate the mirrors, but let each vibrate in a different direction, so-called Lissajous figures are created. As a logical continuation of the earlier experiments with laser projection, I tried to create these figures purely mechanically.
What exactly is a 'cycloid', 'hypocycloid', 'epicycloid' or 'trochoid'? And would it be possible to project these wondrous figures, both mechanically and electronically, with a small semiconductor laser?
As an experiment, I doubled the six-speed gearbox. After seeing the mechanical solution in action, I built the 'projector' with a significantly smaller footprint by electronically controlling the rotating mirrors.
With the mechanically constructed gearbox, the ratios between rotational speeds simply follow from the gear ratios of the gear into which the gearbox is switched. But it is useful to know what the ground speed (in revolutions per minute; rpm) is at any given time.
I started experimenting with IR obstacle sensors to measure small reflective stripes on the wheels. My rpm meter directly measures several sensors and can also display the (approximate) ratio directly on an LCD screen.
With a laser, so-called Cycloids or Lissajous figures can be projected via two rotating or oscillating mirrors. Before I designed a fully electronic control for the different rotational speeds of the motors, I thought it would be instructive to first see how the rotational speed ratios could be controlled completely mechanically.
The final prototype of a gearbox with six ascending whole gears runs remarkably smoothly. However, some custom parts had to be 3D printed.
The logic AND and OR gates of digital electronics can be regarded as the tangible pioneers of Boolean algebra. After all, hardware programming on printed circuit boards with connections forms the basis of what can nowadays increasingly be solved in software.
I took a step back and played around with the logic functions of these gates using my favorite construction material. And it also turns out that mechanical equivalents of these gates can be used to demonstrate that the functionality of the AND and OR function is mathematically interchangeable.
Anyone who ever plays with electronics and circuits encounters practical problems. How do you take care of the power supply of your breadboard and how do you attach test leads and probes to the breadboard as stable as possible?
Or how do you make a neat, uninterrupted clock pulse with a push button for your digital circuit? Potentiometers, push buttons and LEDs for a clear view on your output signals quickly eat up a substantial part of your available breadboard space. In this article I describe my attempts and my most elegant solution to these problems (so far)!
None of the ready-made modules with multiple output voltages turned out to be ideal. They didn't have a current readout, or were way too big to build in a small module case. The wish list therefore led to a plan for DIY.
Now it's time to put everything together. So: designing and printing printed circuit boards and a 3D housing. Then? Assemble and test everything, of course. The movie gives a good picture of the assembly and how the module finally becomes a 'real' usable product.
In the previous part we were introduced to a current sensor, the INA3221. We can use a ready-made board with this chip on it for our experiments. Unfortunately, the board needs some tweaking to make it usable to monitor three truly independent voltage channels or buses.
In this sequel, I designed the circuit, drew the schematic and made a test setup with the modified module, so that we can start testing with current and voltage measurements.
An external 12-volt adapter can be connected to the back of the Zauberling. Connecting the adapter directly to the module, an on/off button and getting a better view of the power consumption of the standard supply voltages (3.3, 5, 9 and 12 volts) remained separate wishes for the future.
Read here how things can get completely out of hand when you do get into tinkering. The Ultimate Multi Power Module is small (3.5 by 7 cm!) and offers four power supply voltages. Voltage, (peak) current and power are monitored per output. Hopefully there is even room for a programmable automatic fuse!
It was time to go through all the new changes, wishes and ideas since the prototype of this module.
Zauberling version 0.2 now has some extra push buttons, four inputs and outputs with different power levels. It is switchable between positive and negative logic and is equipped with a small screen for optimal feedback to the user.
Quite a long time ago, I made my own printed circuit boards. Pure handicraft. You drew the future copper traces on a piece of transparent paper, after which you could transfer it photographically to a piece of printing material with a (often self-built) UV light box. Then develop, etch with dirty chemicals and try to keep your 1mm drill bit intact when drilling. It was still a craft! But these are modern times, so it was high time to investigate how much simpler and more professional this can be done today.
Way back in the 1970s, fischertechnik already offered electronics experiments with alternating voltages. Their transformers had a low voltage AC output for this. I wondered why we don't see that anymore and found out with a pretty dangerous experiment something you shouldn't try at home!
A corny autumn joke, or a groundbreaking innovation? Judge yourself. Prevent neck complaints during tennis or ping-pong matches!
The speed still needs some work, it's just a prototype, isn't it? 😆
In the 1970s, fischertechnik produced the so-called 'Silberlings'. Each small module had its own function, built up with (then modern) electronics. In this video we'll build our own 'Silberling', with a Atmega328P and a TB6612FNG motordriver. Read more...
Or jump directly to the page about the software, or a first applicaition of the 'Zauberling'.
Some time ago I thought along with a fischertechnik club member about a model in which a figure-eight motion had to be described. The challenge was to have an element, such as a cart or ball, describe a path according to a 'bow shape' or 'lemniscate' curve. This produces a movement that intersects itself at the center.
In researching the mysterious lemniscate, I came across some interesting facts. Then I tried out some methods and built a motor controller for the occasion to be able to regulate the speed of the motor.
An uncle, who works as a volunteer at a home for people with dementia, asked me whether I could convert an old rotary dial phone into an MP3 player with nostalgic songs and radio fragments. Recognizing the old faithful PTT telephone with dial, and listening to old remembered songs, often turns out to be a feast of recognition.
After some research into the different Bluetooth modules and their capabilities, I was able to focus on my next goal: Using Bluetooth for the remote control with the joystick shield that has been expanded with an LCD display.
The communication from the joystick shield is compatible with the ArduinoBlue software library used in the model to be controlled. This makes control with the joystick shield interchangeable with the ArduinoBlue app without having to change the Sketch in the cart.
In previous projects universal HF modules where used with the joystick shield to create a remote control unit. With the nRF module a half-duplex connection is possible, but the simple 433 MHz module only allowed data traffic in one direction.
On this site I came across the ArduinoBlue app as a remote control for the fischertechnik car. A logical next step is to use a Bluetooth module on the joystick for the remote control. It turned out to be a lot of information for one project and video, which is why I've cut the subject in two. First, let's take a look at how to establish a full-duplex connection between two Bluetooth modules.
An experiment with an alternative transmitter (and receiver) for the Joystick Shield and the Buggy from a previous tinkering. In various webshops I came across a very cheap set of prints for 315 or 433 MHz for this. So cheap that it made me curious.
The overall quality was indeed not very good. There even seemed to be parts missing and I figured they wouldn't work. So no high expectations. But when I experimented with it, it turned out not to be a bad buy and I even made a funny discovery!
Recently I picked up a 'Funduino Joystick Shield V1.A' for a few bucks. This is an Arduino Uno compatible shield that allows you to create a game console or robotic controller. This nifty little shield features an 2-axis analogue joystick with switch, four large and two additional small switches (buttons) on the pcb.
Add an Arduino and some means of (wireless) communication to get a fully functional remote control unit and add game control or manual robot control type functionality to a project.
A video about my experiments with a cheap wireless PS2 controller for controlling various functions of a self-built model car equipped with an Arduino.
This article about the PS2 controller was also published (in German language) in issue 4 of 2020 of the ft:pedia; a very interesting online magazine about technology in combination with the construction material fischertechnik.
In this video I'll show you my experiments with controlling the pneumatics of a mini pinball machine constructed with fischertechnik.
Experiments with the TSOP4838 infrared receiver for controlling fischertechnik-built vehicles.
Many different motors can be used with the fischertechnik construction material. In addition to the classic mini, XS, S, M and XM motor, encoder and stepper motors are also available.
But additional motors are of course also easily and cheaply available nowadays. With a little effort and a special 3D-printed holder, they turn out to be excellent to use alongside fischertechnik's 'own' motors.
In this video my experiments to make a music playing phone from an old PTT T65 dial phone.
Video about my attempts to control a Nefit room thermostat with an Arduino.
If you have to, then rather something fun and homemade, right?