Home
Videos
Robotics
RaspberryPi 1B+
RaspberryPi 2B
BeagleBoard
Arduino Mega2560
Arduino Yún
Blog 2015
Blog 2016

Supporting this blog

Please support this blog by making a (small) donation via PayPal.

Stay informed ?
You can:
- subscribe to my YouTube channel.
- follow me on twitter
- follow me on Instagram

Any comments ?
You can email me.
Welcome to my Blog on robotics and embedded systems.

All normal pictures have a resolution of 1280x960 and can be viewed in full.
All pictures and videos: copyright Huub van Niekerk
The 2016 blog has been moved to the "Blog 2016" page
2017
17 February

BB: Before doing a power test, the ground rail should be extended. Then, how to get power? And there are both ground and power to be used. Staples? And how? Will it work? Click the image to watch the video.

RPi2/ROS: Getting the motor to run, I change the setup bit by bit: electronics, wiring, software. Measurements give unexpected results. Click the first image to watch the video.

Mydfir: My old riding model needs an improvement in colour recognition, so the calibration can be merged. This shows more harder than anticipated: values and wires need to be checked. Do they match? Red = red, green = green, right? Click the first image to watch the video.

Arduino Yun: Now the console is functional, it takes a moment to realize that I need a pin for the switch. So I start "reading" it (capturing is a better description) and get nice output...which doesn't work for the algorithm. A change in code works much better, but when more electronics is applied, both could work out very nicely. Click the first image to watch the video.

Compilation: I created a short compilation video from the 2008 conventions in Schoonhoven, Vlissingen and Veghel, all in the Netherlands. It was the first year I made some videos. Pictures can be found here.
Mirft2: Adding a touchsensor between the front legs is a nice idea. It requires some code and testing. Will it work nicely or just like the rest: sometime yes, sometimes no? Click the first image to watch the video.

Pictures: Pictures from the fischertechnik convention 2007 in Moershausen, Germany are added to the movies&pictures page. It was the first convention I visited.
RPi1: Adding a transistor didn't work and adding an LED and measuring shows why: voltage too low after the resistor. Replacing it shows a big difference, but is it due to PWM or voltage. Tests bring questions rather than answers. And then a big oops. Click the first image to watch the video.

Arduino Mega2560: Pins 4 and 13 have gone weird, but first I have to fix some electronics...which is controlled by software, as it to be expected. So after changing it a bit, the only unexpected result is a frequency. But why? Click the first image to watch the video.

Hand: The wrist pivot need improvement, but how? Software seems a solution, but somehow this seems to disable the rest. Why? An improvised switch shows an oops which leads to an even bigger oops and the finding of a software flaw. How to go on from here? Click the first image to watch the video.


10 February

BB: To get rid of the wire, a solution is to power the rail. This needs serious reconstruction but how to do it? How to power the rail anyway? Click the first image to watch the video.

RPi2/ROS: When trying out the circuit again, I realized I didn't install all of the software and some settings are yet missing after the big oops. When done, it's time for recoding and trying. And, oops, forgot to use the inscreen-webcam. Will it (or something) work? Click the first image to watch the video.

Discovery: Expanding the tests on pulses and counts gives some remarkable results with differences between ROBOPro and ftrobopy. But why? The hardware is an unlikely cause. Click the first image to watch the video.

Arduino Yun: First, finding the difference between connected and available. Then, what does a keyboard have to do with it? Why not a switch? Then, does the difference between an integer and a character really makes a difference? At least something seems to work, finally. Click the first image to watch the video.

Mirft2: Testing counters again, starting with ROBOPro followed by ftrobopy. Just with the Discovery: remarkable differences, assuming that I'm not doing something wrong. Too bad I've had no technical feedback yet. Click the first image to watch the video.

Compilation: I created a short compilation of the 2009 fischertechnik convention in Erbes-Büdesheim, Germany. Click the image to watch it.

RPi1: Pulse-width should indicate a frequency and voltage. But why doesn't that show on the multimeter? Then, adding some electronics should improve the situation like it did with other test. But will it work? Click the first image to watch the video.

Arduino Mega2560: Looking into the code again, I think I find a solution. This leads me to review the wiring again and replace some. Why do LEDs test ok but don't work on the circuit? Weird behaviour..Then another pin goes weird. Oops.
Click the first image to watcht the video.

Hand: Because the wrist motor is pushed away from the pivot plate, I have to fix it, But how? Then, time to get the wrist motor working with software..it works, but gives me the creeps. This really needs a bi-polar switch, somehow. Click the first image to watch the video.


3 February

Website: The links on the Software page have been fixed and the page is cleaned up.
BB: Time for recoding since the sonar is gone. Will it work with the wire carriages? Last time they were pushed off the rail, so would more weight help out? Click the first image to watch the video.

RPi2/ROS: Booting the RPi2 starts with a major oops: "m: Unknown command" at boot. Fortunately, the microSD card on which everything resides is readable by the laptop. By accessing the contents I find my valuable source code: publisher and subscriber. Next action is to copy everything inside ~/catkin_ws to the server. Now, what should I do next? Reinstall the SD card? Seems the only thing I can do but will it work? Click the image to watch the video.

Discovery: Continuing with the counter, some tests and recoding. This shows some very odd results, but are they wrong? Click the image to watch the video.

Arduino Yun: First a problem: I can't connect. This turns out to be a wire problem: the LAN cable isn't there and after connecting, a reboot is needed. Then, no internet. But why? Back to code: somehow it doesn't work right, but with the console going some things get clear. Click the image to watch the video.

Mirft2: For checking the counters or pulses of the motors, I change the code. Then some surprising results come out giving doubts on the hardware, but which part? In a final test, the results are even odder. How come? Click the first image to watch the video.

RPi1: Using hard pwm turns out to be my second attempt, in a way. I have to switch to python, and install some software. Then making a choice between GPIO and RPIO? Finally, some calculation or/and conversion. Will it work? Click the first image to watch the video.

Arduino Mega2560: Checking the frequencies with the alternative method gives unexpected results. Why are the values different? Also, why the factor change? Pin 13 is a very odd case, but why? Click the first image to watch the video.

Hand: The wrist needs to be wired, but a reconstruction is necessary. After the wiring, how does it work? The diagnostics reveals a 2 problems. How to solve those? Click the first image to watch the video.


27 January

BB: Back to wiring issues: how to solve it? This leads to new ideas and reconstruction. Will they work out? Click the image to watch the video.

RPi2/ROS: Examining the code leads to changes: using switch input, separation of both data. But also some odd behaviour. And then there's a motor... Click the image to watch the video.

Discovery: So the pulse count seems to be an issue. After some recoding and re-thinking, I decide to make the screen output more clear, which leads to some odd finding. Click the image to watch the video.

Arduino Yun: First I try the wired USB connection, then back to Wifi and finding how to add it to my own network. Next, the serial monitor, which isn't serial and needs some code. But does it work? Click the first image to watch the video.

Mirft2: Looking at the gears there's 1 part on both sides that needs improvement and another that maybe can't be improved. So how to go on? Does the code need a change? Click the first image to watch the video.

RPi: Pwm testing keeps revealing odd and possibly contradicting results: the motor doesn't work and the LED works. Then some new searching reveals a solution: soft vs. hard pwm (RPIO.PWM?). Click the first image to watch the video.

Arduino Mega2560: Since pin 4 and 13 don't match in frequency, it's time to find out more using a different way in code. This shows something is wrong, but can it be corrected? And how about the desired 40-120 Hz range? Click the first image to watch the video.

Hand: Time for the wrist motor: which one to use, where to put it and how to wire it? Does it take yet another reconstruction? Click the image to watch the video.


20 January

BB: Adding a wire-carriage for smooth movement, does that work? Adding 1 or 2 springs to prevent bumping, will that work? Some oops, unexpected results and conclusions. Click the image to watch the video.

RPi2/ROS: Trying to use ROS and the GPIO at the same time takes quite an effort. Then, making the switch do what it should do, takes additional electronics. Showing it all on in-screen video, requires 1 more step. Click the first image to watch the video.

Discovery: Sound and motor tests again on both firmwares as well as ROBOPro. This reveals a surprising problem. Another problem seems to have returned: wiring. Click the first image to watch the video.

Arduino Yun: Last time, testing didn't go as well as hoped. So, it's time to rewrite some of the code and check some of the wiring. Will it work? Click the image to watch the video.

Mirft2: After the frame reconstruction, it's time for testing. However..some things aren't as they should be: gear not aligned, knots at the wrong place, teeth not fitting. After fixing(?) some testing follows. Click the first image to watch the video.

RPi: Checking on pwm only: showing way to high frequency at the lowest setting. Can I change the code? Can I change my own code? Click the first image to watch the video.

Arduino Mega2560: Measuring frequencies leads to changing the circuit a bit and inspection of the code. Then a new test casts doubts on basic information. What's right and what's wrong? Click the image to watch the video.

Hand: A pivot gear modification badly needed and this time it seems to end up fine. Except for the motor, but how to fix that? Finally, a look at the arm. Click the image to watch the video.


13 January

BB: Replacing a broken lenslamp solves 1 problem, but the carriage still doesn't do what I want. Some testing reveals the issue: recoding is needed with a nice result. Click the first image to watch the video.

RPi2/ROS: Trying to figure out how to use my own msg file and getting the GPIO to work together with ROS leads to unexpected results and questions. Click the first image to watch the video.

Discovery: Time to relocate the motor tests to the original firmware. Any other different (better?) behaviour? Click the first image to watch the video.

Arduino Yun: Time to connect the Yun to a breadboard and bring the circuit there. Will it work as well? Something needs to be changed, including some additional hardware. Click the first image to watch the video.

Mirft2: After doing the feet, it's time to let the gears go properly. This takes some serious reconstruction of the frame but will it work out as intended? Click the image to watch the video.

RPi: Some new attemtps to simulate pwm brings questions. Then, back to the real circuit: how does the motor work anyway? Is it really pwm controlled? Click the first image to watch the video.

Arduino Mega2560: Some more simulation gives some clarity, but in what exactly? Then back to the real circuits, with some oopsies and code changes with clear effects. Click the first image to watch the video.

Hand: Reconstruction (again!) of the pivot gears seems to go fine. Then a (final?) test reveals the real problem (oops), which leads to yet more(!)  reconstruction to be done. Click the image to watch the video.


6 January

BB: Checking the code leads to some changes and testing leads to questions about wires, lamps and the interface. Click the image to watch the video.

Discovery: Considering the results of last time, some more code changes are necessary. Testing shows it doesn't really look promising. Click the image to watch the video.

RPi2/ROS: Going on with trying to publish a number meets with some hurdles: C++ isn't Python, several adjustments, and why don't examples always work out? Click the image to watch the video.

Arduino Yun: It's time to explore some more by doing some more programming and add electronics. Click the first image to watch the video.

Mirft2: A gear is not aligned anymore which shows a continuing problem. Then, feet need to be fixed and the hind legs need to be reconstructed. Click the image to watch the video.

RPi: The pwm simulation isn't yet really what it's supposed to be. Also, the motor isn't a DC motor. So things need to be redesigned. Will it work? Click the image to watch the video.

Arduino Mega2560: Improving simulation leads to unexpected results and necessary changes. How do toolboxes interact? Click the image to watch the video.

Hand: Considering the space around the wrist, I go for a slight reconstruction. Then tests show there's a wiring problem, which is solved quickly. But that's not all. Click the image to watch the video.