Fixing Digital Calipers

Hi there! In this post I'm going to show you how to fix a digital caliper in a very easy way. In fact, it's so easy that I had serious doubts about it until I tried and saw the results with my own eyes. :P

(Click the photo for better resolution in Picasa Photostream)

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New Publication: Minimalistic Vision-based Cognitive SLAM

Hi! There is a new paper in the Publications section entitled "Minimalistic Vision-based Cognitive SLAM" which was presented today at ICAART 2012 - 4th Int. Conf. on Agents and Artificial Intelligence, in the Special Session on Intelligent Robotics. You can download it in the Publications section or just click here.

Below you can see the presentation that was used. Hope you like it :)

Minimalistic Vision-based Cognitive SLAM on Prezi

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Using Piklab with Tiny PIC Bootloader

Following my previous post on How to Setup a PIC Microcontroller Development Environment in Ubuntu 11.10 Oneiric Ocelot With Piklab + SDCC, now I'll show you how to use the Tiny PIC Bootloader with Piklab.

Piklab already has programming interfaces for various programmers, including the Tiny Bootloader. To configure it you must go to "Settings > Configure Programmers... > Tiny Bootloader" and then set your serial port and it's specific settings. In my case, since I use a USB <->Serial TTL Cable (see my previous post on how to make a Low Cost (1,85€) USB to RS232 LVTTL Serial Cable), I configure it with the following data:

• Port Selection: /dev/ttyUSB0
• Specific > Port Speed: 19200
• Specific > Timeout: 300
• Specific > No of Retries: 5

Get the flash player here: http://www.adobe.com/flashplayer

After inserting all the correct configurations for your serial connection, Click "Apply" and you're ready to go. To program you just have to go to "Programmer > Program". Do not forget to click the Reset button of your development board to reset the PIC and initiate bootloader when you want to program it.

Easy, right? Yes, but it doesn't always work. :( I had it working when I used Ubuntu 11.04 Natty Narwhal and some version of Piklab that I can't remember now but since I upgraded to Oneiric Ocelot and a new version of Piklab, the Tiny Bootloader programming interface stopped working. However, there is another easy way to use Tiny Bootloader with Piklab.

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CNC Controller Board

In this post I'll make a short description of the CNC controller boards that I'm making available for you to download and use to control your own CNC. I'm posting 3 version of the same board, but only the first one has been really tested and has been working inside my CNC Control Box for a long time now (see my previous post Homemade CNC:TheMaker1). I'm 99% sure that the other boards will work too because they only have minor changes. I'll explain them to you in a few moments.

All the boards are made in Kicad. The design of the boards is based on the CNC3AX designs, but it uses other components that I had available at the moment that I made the board for my CNC. I advise you that I just wanted to get my CNC running, so I didn't make any careful selection of the most appropriate components and I didn't make the math to calculate the best values for the resistors. I just made it with the components that I had laying around. The boards design can be split in three parts:

1. Isolation - it has Vishay's 6N137 optocouplers to isolate the parallel port from the rest of the circuit;
2. Drivers - the ST Microelectronics' L297 drive the motors in unipolar mode (if you prefer bipolar you can change the schematics and boards at your will);
3. Power Interface - a bunch of Vishay's IRL510 N-channel FETs working as switches controlled by the L297 Drivers.

(Click the photo for better resolution in Picasa Photostream)

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Homemade CNC: TheMaker1

Hi! In the following lines I'll present a project that has taken a very long time to complete: my homemade CNC machine. From the first tests and tryouts with various materials to the actual machine 2 years have passed. More important stuff always made me delay the development of the CNC. However, I estimate that the total amount of time was 3 weeks. I think CNCs are a big challenge for anyone since it involves a lot of mechanical, electronics and computer engineering (although we can bypass the computer engineering part by using available software). It was a challenge for me, with lots of frustration along the way because of my lack of skill to make the parts with the few tools I had, but now I can happily say "Mission Accomplished!":D.

(Click the photo for better resolution in Picasa Photostream)

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