Ohnitsch Cartoons Cartoons, Electronics, Acrobatics and other things.

10Sep/150

Eurofurence 21 report

Here's the report from this year's Eurofurence! :)

16Jun/151

Using Eclipse instead of Keil C51 uVision for EnOcean firmware development

This article describes how to develop Firmwares for EnOcean EO3000I based modules with Eclipse.

After using the rather mediocre Keil uVision for too long for developing Firmwares for the STM3xy modules I thought that there must be a better solution, and voila, a day of work later I managed to get everything up and running with Eclipse! Finally autocomplete, indexing and all the amenities of Eclipse.

18Mar/1517

Measuring heart rate with a piezoelectric vibration sensor

While trying to create a circuit that detects whether water is flowing through a pipe by measuring the vibration with a piezoelectric sensor, just to see what happens I taped the sensor around my finger and - to my surprise - got values that were a very noise-free representation of my heart rate!

Piezo sensor taped to finger

Piezo sensor taped to finger

Analog values from a piezoelectric sensor taped to my finger.

Analog values from a piezoelectric sensor taped to my finger.

This is even easier than using LEDs as it only requires a piezoelectric sensor and an Arduino. (and a piece of tape)
The sensor I used is a DFRobot Piezo Disc Vibration Sensor Module.

When defining an arbitrary threshold (e.g. half of the maximum measured value), the rising edge of the signal will pass the threshold once per heartbeat, making measuring it as simple as measuring the time between two successive beats. For less jitter, I chose to calculate the heart rate using the average of the last 16 time differences between the beats.

Here's a quick and dirty code that calculates the heart rate and outputs the average heart rate over the last 16 beats at every beat:

If you would like to try this at home, just connect the analog output of the sensor to A2 (or change the code) and connect the 5V and GND lines of the sensor.

20Feb/150

Art Trade

Here's my part of a recent art trade, inked with a Pentel brush pen and Copics!

Surgery on a teddy bear

Filed under: Cartoons, Drawing No Comments
14Nov/140

Friday Sketchdump #109

Cartoon bat kangaroo.

Here's the sketch of a badge I made for this year's EF...

Colored bat kangaroo.

...and the finished drawing.

Cartoon fruit bat.

Fruitbats are badass.

Batkat and Baseball bat collect money for charity.

Something I doodled into Titash's sketchbook after EF!

31Oct/140

Friday Sketchdump #108

Catching up with more old drawings!

Hi!

Hi!

Kangaroo on a plane

I drew this on a flight from the Netherlands to Austria last year.

I drew the mascot of a pub in Vienna when we were there. They serve over 300 kinds of specialty beer.

I drew the mascot of a pub in Vienna when we were there. They serve over 300 kinds of specialty beer.

A drawing for friends we were invited to.

A drawing for friends we were invited to.

24Oct/140

Friday Sketchdump #107

Catching up with some really old art for my Sketchdumps :)

Little red riding hood and a wolf.

Private commission

Baseball the spectacled flying fox getting a ride on Henrieke's bird character Jack.

Baseball getting a ride on Henrieke's character Jack.

Some kangaroo sketches for a job.

Some kangaroo sketches for a job.

Another kangaroo drawing for a different client, I believe it was a bouncy castle rental company.

Another kangaroo drawing for a different client, I believe it was a bouncy castle rental company.

10Oct/142

Repairing a Sony MDP-650 Laserdisc player

It took me years to find a decent Laserdisc player in Austria, and a few years ago I managed to get a Sony MDP-650 at a foreclosure auction. I was the only bidder. There is neither supply nor demand for LD players in this country, which isn't surprising as the system was never really popular here, so barely anyone even knows that these things exist.

Anyway, my player worked perfectly fine for a few years (I just had to replace the belt that connects to the gear lifting the LD at first), but recently it stopped working.

What happened was:

  • The disc gets raised
  • The disc gets lowered (this is how it always goes, so nothing unusual here yet)
  • I press play
  • The disc gets raised again
  • The laser module moves back and forth around 4 times, with about 1 second between each try
  • The disc gets lowered again, the player just displays "disc"

It was the same for CDs and LDs, which made it unlikely for the Laser to be the issue as it was unlikely for both Lasers to break at the same time. I suspected the skew motor, which keeps the Laser in focus, but upon closer examination the skew motor was fine. I did however manage to get the player to play discs by turning the skew motor in a way that the Laser is very low. The player could then read discs for a few seconds.
Thanks to a suggestion by the user rein-o in a thread I posted at the lddb.com forums I figured out that the discs were at the wrong height, so I found out where to adjust that and got it to a height where the player seems to be working after a few tries. It seems that the platter slipped down slowly over the years and just needed some readjustment.

Spindle of a Sony MDP-650 LD player

I adjusted the height of the Spindle using the little screw on the side.

I hope this helps if you're experiencing the same problem. I also have a PDF of the Sony MDP-650 service manual, so if you're in need of that, just drop me an e-mail!

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11Sep/140

Bon anniversaire Titash!

Here's a drawing I did for my Nutella-loving friend Titash's birthday!

Titash. eating Nutella.

Titash. eating Nutella.

 

Filed under: Cartoons, Drawing No Comments
8Jul/141

Willie Wasbeer

After a month of hard work, Henrieke and me finished Willie Wasbeer, the new mascot of GaiaZoo in Kerkrade, Netherlands. As with every costume we make, there was a lot of new things we tried, such as padding for the legs made out of foam strips to allow good airflow, lasercut eyes and padded arms. Everything worked out perfectly, as you can see in the Video of Willie's first performance!

3May/140

PersonalJava Tutorial

Not quite what I usually post and oddly specific, here is a PersonalJava tutorial to help people getting started with developing Java applications for old Handhelds.

22Apr/140

Audiodile: Sounds of the Future

Here's a poster I did together with my friend Eligecos for Audiodile's dance at BLFC, an 80s themed con. I did all the lineart and a rough background, Eligecos did the shading and some more of the background since my PC couldn't handle the giant file anymore!

80s-themed poster for Audiodile's dance at Biggest Little Furcon, drawn by karpour and Eligecos.

Poster for Audiodile's dance.

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7Apr/140

USA Trip 2014 – Monday, April 7th

We stuffed our stuff in the car, sent our phones back to Chorca, filled it up at the gas station and went to the airport around noon. This day could've been terrible, but it wasn't thanks to lots of nice people we encountered. At the rental car return we discovered that the car wasn't filled up completely despite my best efforts to do so. I would've had to pay 12$ for the missing gas, hadn't it been for the nice guy working there who believed me that I was at the gas station 15 minutes ago and did my best to fill the tank. Out of the car, we were on our own with a giant box, a travel bag and a giant suitcase with a completely busted wheel. And no luggage cart anywhere. Another nice guy from the rental company came for help and offered us a ride to the terminal with one of the rental cars he was parking, that was incredibly nice and saved us so much trouble! At the check-in counter we discovered that our first flight was 30 minutes delayed, which was a problem as it would only give us around 10 minutes to catch our next plane in Salt Lake City. After the lady there made lots of phone calls and couldn't find a better connection, we agreed on trying to make it and getting a hotel in SLC in case we didn't make the connection.

San Jose airport from above.

San Jose airport from above.

Flying over salt lakes.

Flying over salt lakes.

Salt lake city airport.

Salt lake city airport.

Well, we did, thanks to the gate for the next flight being just a few meters from our arriving gate and us sitting all the way in the first row thanks to the helpful flight attendants. The second flight from Salt Lake City to Paris was much more relaxed as we didn't have to worry much about missing our next connection. We were very impressed by the leg space and the entertainment system in the Delta plane and time way flying by. We watched "The secret life of Walter Mitty", and at one point I noticed some weird cloud outside. It was way past sunset, so I was confused by such a bright cloud. Since we were over Greenland, I thought it could be Aurora Borealis, and the camera confirmed it! We totally saw northern lights, lots and lots of them! We spent quite a while taking photos as a team, Henrieke operating the camera and me holding a jacket over her each time in an effort to block any light coming from inside the plane that would ruin the 6-second exposures we took. The photos turned out quite nice considering we didn't have a tripod and the plane was moving! The rest of the flight we dozed off and ate some tasty plane food.

Northern lights!

Northern lights!

More northern lights.

More northern lights.

We had a wonderful view of the night sky!

We had a wonderful view of the night sky!

The entertainment system in the plane left little to be desired!

The entertainment system in the plane left little to be desired!

Beautiful Charles de Gaulle.

Beautiful Charles de Gaulle.

The rest of the trip was uneventful, we arrived in time in Vienna and to our big surprise our luggage did as well! Johannes picked us up, we went home, unpacked and tried our best to fight the jet lag. The End. Thanks to all our friends for making it such a great trip! :)

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6Apr/140

USA Trip 2014 – Sunday, April 6th

I think today is the least eventful day as we spent most of it trying to stuff everything we brought into 3 pieces of luggage. 60 Artistic Visions books, 7 yards of fur, a ton of CDs and Laserdiscs, lots and lots of Japanese food, Oreos, it all adds up. Before noon, Chance, an avid photographer, invited us over to have some professional photos taken of Baseball, Dog and Kiki! We squeezed it into our schedule and got some really nice shots! Thanks again Chance! The only other thing we did outside was going to Jamba Juice with Croc and getting some lunch at Panda Express, then more packing. In the evening Chance and Furahi came over and we ordered some Pizza and watched Cosmos together. Can't say no to Neil Degrasse Tyson! After that, more packing and eventually trying to get some sleep!

 

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