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My selfmade servo controller

Posted: 17 Mar 2011, 13:06
by skaltura
Hi there,

I'm a big fan of the Lego Mindstorms kit, and decided to make my own servo controller because the Mindsensors servocontroller is to expensive for my budget.
It works by using the I2C signal from the Lego brick, and the I2C write block from Mindsensors.

I can't select the servo speed, but I can adjust to speed by inserting a delay time in the program, so It's not as sophisticated as the Mindsensors servo controller, but it does the job... :D

I would like to hear what you think of it, so please take a look at it, on my website.
servo_nxt.jpg
:arrow: http://www.hacsoftwarecompany.com/?proj ... _nxt_servo :arrow:

Many thanks !!

Re: My selfmade servo controller

Posted: 17 Mar 2011, 13:17
by mightor
Nice sensor! What controller did you use to control the servos?

- Xander

Re: My selfmade servo controller

Posted: 17 Mar 2011, 14:26
by skaltura
I used a PIC Microcontroller, type 16F819. This had it's own I2C communication, so it's easy to attach this to the Lego brick. And the PIC microcontroller also can produce a standard servo output signal. Not that difficult to make, and quite cheap. It cost me about 20 euro's in parts.

I see that your also from the Netherlands, so I'll post the same link to my site, but in the Dutch language for those who rather read in their own language... ;)

http://www.hacsoftwarecompany.com/?lang ... _nxt_servo

Thanks for your reply

Re: My selfmade servo controller

Posted: 17 Mar 2011, 20:11
by mattallen37
Very cool :P, but what a coincidence :o! I was just about to post about a servo controller I made (though not nearly an nice)! :lol: Thanks for sharing. It looks really great!

Re: My selfmade servo controller

Posted: 17 Mar 2011, 22:28
by skaltura
Indeed a coincidence...

I must say that I'm a bit of a perfectionist, so I made a PCB for my project, but yours is great too. And as long as it works, it's cool in my book !
Thanks for your reply

Re: My selfmade servo controller

Posted: 17 Mar 2011, 22:56
by mattallen37
Well, I'd LOVE to be able to make PCB's, but I am not really sure how to design them yet.

BTW, you of all people should understand what I want. I want a breakout for the mindsensors NXT jacks. I want them broken out to 0.1" holes. I could then solder either a header, or wires to it. It would be great for breadboarding and custom sensors (with perfboard). I have no idea how to accomplish something like this, so I asked mindsensors to consider making it. I haven't gotten a response, so they probably didn't like the idea. What would it cost to develop something like that, and have the PCB's made? They would be tiny PCB's (about 2x2 cm). I love soldering, so I would just need bare PCBs. I could probably use 10 or so to begin with.

Re: My selfmade servo controller

Posted: 18 Mar 2011, 00:28
by nxtreme
DorkbotPDX makes fairly cheap PCBs. You could probably get nine PCBs (they are sold in sets of three) for about $14 US. That includes shipping. Not bad if you consider it. Eagle is one of the most popular schematic and PCB layout editors. It is harder to learn than others, but it is very powerful. Best of all, it's free for non-commercial uses. I use it, and even though I've never actually made a PCB (go figure... :P) I would recommend it to anyone.

P.S. Check out the SparkFun tutorials for Eagle, they're pretty helpful.

Re: My selfmade servo controller

Posted: 18 Mar 2011, 00:40
by mattallen37
Thanks for the link. Those prices seem really good. I guess I'll try to figure out how to use Eagle (I already installed it a few days ago).

Re: My selfmade servo controller

Posted: 18 Mar 2011, 09:01
by skaltura
mattallen37 wrote: I want a breakout for the mindsensors NXT jacks.
I actualy made a breakout jack for the NXT. You can order the NXT jacks from Mindsensors.
nxt02.jpg
nxt01.jpg
Sorry, the photo's are a bit blurry... I dropped my camera and now it can't focus anymore :oops:

If you can't make PCB's, you can just solder wires to the jacks and put then into your breadboard.

Re: My selfmade servo controller

Posted: 18 Mar 2011, 09:05
by mattallen37
That is basically exactly what I mean/want. The only thing I might want different, is for the jack to be turned 90 degrees.

Yes, I know I can buy them from mindsensors, but I want a breakout (like yours), instead of soldering wires directly.

Currently, I am using a wire cut in half, broken out to a 6 pin header.