Risto H. Kurppa » hardware

Nokia Kinect @ Nokia World, London

Risto H. Kurppa — Thu, 27 Oct 2011 04:26:56 +0000

A new concept device from Nokia: it’s operated by twisting and bending the device itself! That’s quite different from the touchscreen stuff we see all the time.

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Automaatio Fair 2011

Risto H. Kurppa — Sat, 08 Oct 2011 14:37:27 +0000

Talking about delta robots, here’re two more from this week: Automaatio Fair in Helsinki

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Fun with servos

Risto H. Kurppa — Mon, 03 Oct 2011 08:44:40 +0000

Servos are cool. They’re small motors that can be told to go to certain position with decent precision. They’re cheap, powerful and extremely easy to control for example with Arduino.

I use RC microservos at my work with Arduino to run this:

So what else have people done with Servos? Here are some neat videos.

Automatic book page turner (for DIY book scanner)

Using servos as output & input device

Volksrobot – Delta Robot

Another Delta Bot

Arduino Humanoid Robot

What’s your plan?

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GPSTrack GPS logger on Linux

Risto H. Kurppa — Sun, 07 Aug 2011 20:58:05 +0000

Last weekend I inherited a GPS tracker from my aunt who got it as subscription gift from a magazine. It says ‘Geotech’ in the back, it has a small 1 inch LCD screen, a on/off button and a four-way button (M, UP, DOWN, ENTER).

GPS tracker

Five memory slots to save positions
Compass chip to show north even inside. Not THAT reliable but gives some kind of hint
Shows distance to any of the five stored positions
It doesn’t show coordinates on screen, only time and date
Walk/Bike/Car modes (5, 15 and 80 km/h I think the manual said)
2x AAA batteries
Is told to work as a GPS antenna (connected over USB to computer to navigate/draw track, exports in EMEA format)
Sirf IV chip, they say but not sure if I believe it
miniUSB slot, cable & software (Track by Starview Software)
backlight
battery and GPS signal strength meter

[ 4883.010028] usb 7-1: new full speed USB device using uhci_hcd and address 2
[ 4883.408261] USB Serial support registered for pl2303
[ 4883.408396] pl2303 7-1:1.0: pl2303 converter detected
[ 4883.420176] usb 7-1: pl2303 converter now attached to ttyUSB1
[ 4883.420198] usbcore: registered new interface driver pl2303
[ 4883.420201] pl2303: Prolific PL2303 USB to serial adaptor driver

Bus 007 Device 002: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port

As you see, connecting it to Linux over USB shows it as Prolific PL2303 Serial Port USB adapter and it appeared as /dev/ttyUSB1

To make Wine see the USB serial port, run ln -s /dev/ttyUSB1 ~/.wine/dosdevices/com1

I was able to install the program smoothly. It runs but the built-in Google Maps view doesn’t work. However I’m able to download the track from the device and save it in .track format. Now when I open this .track format with the app, it gives me the option to store KML and GPX.

However saving in GPX (and KML?) fails and the result is a broken GPX as the program, for some reason, writes coordinates in

instead of

so search and replace all commas (,) to periods (.) and the tracks start to behave.

A nice device with a decent battery duration, about 10 hours or so on two AAA’s it needs. GPS track isn’t that great: most of the time it’s missing the elevation information and then every now and then it takes me to over 20 kilometers. However it gives easily a nice overview of the route.

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IR light pen for WiiMote Whiteboard

Risto H. Kurppa — Mon, 20 Jun 2011 14:31:57 +0000

I built an infrared pen to be used for Multi-touch Whiteboard with Wiimote.

940nm 1.2V IR led
2.2Ohm resistor
Awfully low quality push button
1.5V AA Battery
Plastic
Hot glue
Soldering station

Side view. She's a beauty, right ;)

Bottom view. Not that beautiful.

Now waiting for Aapo to post some results how well it works..

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Normal day at work

Risto H. Kurppa — Wed, 09 Feb 2011 14:42:11 +0000

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3D printing, day two

Risto H. Kurppa — Wed, 22 Dec 2010 00:29:28 +0000

Encouraged by the results from yesterday, we continued testing our Reprap (clone) today. It’s not a real Reprap as.. we.. we only use the extruder from Reprap, everything else was already existing for other purposes and suited 3D printing (like the translation stage, control software).

I installed Repsnapper on the control computer running Ubuntu 10.04.1 to create Gcode from the STL files you can download from example from Thingiverse. Here are some of the models we tried to print:

Parameters

We tried various Repsnapper settings to improve the print quality. We learned that there is a nice list of parameters to tune for the best printing result: extruder material width, extrusion speed, extruder nozzle temperature, layer thickness, XY speed, maybe also temperature of the environment, filament material and so on. We mostly played with extrusion speed and layer thickness and also experimented with infill settings. Infill is the part where space between the walls is printed full – usually it’s some kind of grid, not 100% full of ABS.

We also tried printing on a heated bed (100C, covered with Kapton tape). Not sure what was the effect of the heating but maybe it improved the quality on the first two or three layers by letting the melted plastic cool down a little bit slower.

Success

Generally it was a success. We enjoyed a lot seeing the printer make something with a clear shape. We saw the work flow from a thingiverse STL file to gcode to printed object happen.

Problems

The Gcode Repsnapper generates isn’t that perfect after all. First, we have an A axis controlling the extruder and Repsnapper gives us E, and it’s hard-coded there in many places. An EMC2 filter would help here. The code it generates doesn’t seem to be very optimized. It leaves small bits unfinished here and there and then comes and fixes them later. Also we don’t know if it’s normal to have the sides of a printed block every other layer straight line and every other in a waveform caused by the infill. Of course it would look nice if the sides were made of straight lines next to each other, nothing more. So we’ll try some other G-code generators soon.

Antiooze is the feature, where the extruder is moved back a little bit so that no more filament is extruded, when the head moves from an end position to the next start position. As we didn’t have it working very well, there are many extra, unwanted printed lines between the walls. Moving back does ease the pressure in the nozzle but it’s way too slow to actually stop the filament from coming out of the nozzle. So tried it but it really wasn’t worth using, making printing very slow.

The steppers of the translation stage seems to be missing some steps as most of our prints lean a little bit to -X dir. Printing 4 mm high object already has 1-2mm of offset on a straight wall. Anders also tried slower acceleration but it didn’t help.

Results

Also check what Anders wrote.

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First prints with Reprap, the Open Source 3D printer

Risto H. Kurppa — Mon, 20 Dec 2010 22:38:19 +0000

Take an open source idea, three guys, metal workshop, some knowledge on the required software and hardware. Four moths later you have a 3D printer.

I heard about it some years ago. RepRap – the printer that could print 3D objects – even print parts for another RepRap.

End of August I started to talk about it to someone in our Lab. He got excited – and we decided: Let’s do it. First we’d start with the extruder (the part that feeds the ABS plastic through a heated nozzle. The ‘print head’) which is the most critical part.

Software

Also Anders joined the team. He’s been building his own CNC mill for a while and he is familiar with EMC2 software and all the other bits of software, file formats and everything you need to convert 3D designs into 3D objects. He said it shouldn’t be a problem to make a translation stage to move as we wanted. Sound’s good!

Parts

So I ordered the thermal barrier & nozzle, 2x thermistor, 5xbearing and NiChrome wire (30.45€ all together) from mendel-parts.com and 1lbs blue ABS from robomaa.com (23.90€). It took quite a long time for all the parts to arrive. All costs about 55€.

The stepper motor was taken from an old 5 1/4 -inch floppy disk drive..

Extruder

While we were waiting for the parts, we got some help from the guys at our mechanics workshop: they NC-milled us the Wade’s Geared Extruder as we didn’t have a RepRap to print us these parts. It was beautiful.

The parts arrived, we put the printing head together. Then there was a break of many weeks when nothing happened in the project. One day we again got interested, taped (Kapton) the NiChrome wire on the nozzle, added the termistor and tried it rotating the gears manually. We were able to get some blue ABS come through the nozzle. WIN!

Then Anders and Antti started working harder. They built electronics to control the stepper, heater and thermistor.

Translation stage

One day we went and got an old, huge, heavy translation stage from the storage. Then made the first EMC2 tests with the extruder. WIN again! So now we only needed to mount the extruder on the translation stage, build the cables to connect the computer, translation stage and the extruder and put it all together. The guys at the workshop helped with the mounting (Great work again!! Beautiful!) and improved the grip in the filament feed rod.

Today we put it all together. Here’s the result.

Then I had to leave but Anders and Antti kept on going and succeeded great!

We still have to work a bit on the software: need to convert .STL files (for example from thingiverse) to G-code understood by the EMC2. The extruder is the A-Axis in absolute mode. At the moment our best guess is RepSnapper. Maybe also work on the temperature control and ABS feed rage.

Looking good!

Here are some comments from #reprap irc channel people wrote when I linked Anders’ blog post.

22:55 < c> good evening 22:55 < t> yes it is :) 22:57 < rhkfin> it's great! 22:59 < c> I would not agree as much on that as you :) 23:02 < rhkfin> c: http://www.anderswallin.net/2010/12/3d-printer-first-test/ <- that's the reason of being happy :) 23:02 congrats rhkfin, now the fun starts. 23:02 < c> rhkfin, that is great news :) 23:02 < c> sexy gears 23:02 < rhkfin> indeed :) 23:02 < c> that brightened my evening some :) 23:03 < rhkfin> c: thanks :) We have a metal workshop that wanted to help :) 23:03 < s> looks very good! 23:03 hmm using emc2? 23:03 < rhkfin> b: yes ... 23:03 < r> omg im in love with those gears 23:03 that extruder is made of sexy. ... 23:05 < c> congrats to the print! :) ... 23:10 rhkfin, 0.5mm layers are pretty damn thick, I'm suprised it worked at all. 23:10 < rhkfin> b: so you think it should be thinner with slower feed? 23:10 < d> b: it is pretty usable btw 23:11 if it works use it. I was never able to get above 0.4mm layers. 23:11 < rhkfin> ok 23:11 your prints will be fast! 23:11 < rhkfin> :)

Now go and check Anders’ blog post for more.

No related posts.

Tags: hardware, planet-fnoss, planet-reprap, planet-vapaasuomi, reprap

Samsung Galaxy Tab

Risto H. Kurppa — Mon, 22 Nov 2010 18:52:32 +0000

I today had the possibility to play a bit with Samsung Galaxy Tab that tries to challenge the Apple iPad. Tab runs on Android and the user interface looks very much like the one of Galaxy S phone.

7″ screen is nice, plenty of room to have a decent sized on-screen keyboard, watch videos, read e-books or PDF files
Galaxy tab was maybe a little heavy – but it also fealt very strong built that most likely will not break easily
What else.. Volume & power buttons, 4 buttons below the screen.
Camera had a nice panorama feature. I took a 8 photo panorama inside: photos were not sharp but the panorama stitching was done very well and fast!
Android Market with lots of software – this is what makes the device really useful

What I recently bumped into was the fact that yes, even though you can buy apps from Android Market to all (Google-authorized) Android phones, all the software will not run on all hardware.. Not enought computing power, too small screen… It’ll be interesting to see how Google manages this in the future.

Don’t know what else to say. I’m sure there are people out there who find it useful – I myself would like to have a tablet with more open Linux OS :)

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iPad – first experiences

Risto H. Kurppa — Tue, 04 May 2010 20:24:20 +0000

iPad – it’s here to change the world!

It’s small, slick. It looks extremely good. It feels heavy enough to convince you it’s of strong build.

E-book reader. Very easy to scroll pages, just slide your finger from side to side. Nice sharp text screen, very easy to read.

Tried the map application. It had Google Maps (street map, satellite, terrain..) there, GPS pointed me where I was even though I was inside a huge metal building, about 2 meters from a window. Multitouch allows extremely cool zooming by pinching my two fingers closer or further from each other.

Screen rotation works nice, there’s a hardware key to lock the screen position.

Youtube application wasn’t able to show a single video. Don’t know if it’s the flash fight Apple & Adobe currently have, but it didn’t work.

Tried the Safari web browser. The UI is very simple, I guess it’s the same as what iPhone /iPod Touch has. To me it was a bit of a pain – we searched for a free books in the internet (Project Guthenberg) and were able to find them, but we couldn’t come up with a way to save a file from the browser. In the end we did find out that holding your finger long on a link it’ll open a short menu including ‘copy’. Then you can open the PDF viewer, tell it to find a book from the internet, then do some magic to paste the previously copied URL to the address field to download the PDF. Easy? Not at all..

The hardware button on the front takes me always to the main menu/main view. I didn’t try what happens if one presses it longer. As you can run only one app at the time, you’ll be using this a lot. As iPad doesn’t do multitasking (as far as I know it means that you cannot listen to music while reading a book and so on..), you keep starting and closing applications all the time. I guess this is the reason why a PDF reader has to know how to download PDF files from a given URL, has it’s own download manager and so on.

Appstore having huge amounts of cool applications for iPad, it must be a neat device and many people will enjoy it.

It’s understandable that Apple wants to generate as much money as possible but it must be at least equally understandable that I have problems with the way they do it.

At this stage I tell you that this iPad isn’t mine. Someone I know bought one from US and I had the possibility to play with it for around 15 minutes.

I guess that after using Openmoko Freerunner for almost 2 years now, I’d very soon get frustrated with the limitations Apple has set for it’s devices. Having to pay for almost every software, not being even able to start it without Windows or Mac OS, move files over with Linux, not having multitasking, not being able to SSH in it, not being to install any app I or someone else has written and so on. They generate money and make slick devices, but the rest is not fair play.

One question I came up with while using it – can I run Openstreetmap instead of Google maps? Yes, I can.

I need to do soon something with the theme my blog uses.. the content area isn’t wide enough for Youtube videos :/

Apple iPad Apple announced their tablet device, iPad two days ago. Immediately...