Author Topic: Building 50$ robot Micro Controler Webbot's version  (Read 2448 times)

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Offline huevonTopic starter

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Building 50$ robot Micro Controler Webbot's version
« on: April 20, 2010, 03:21:57 PM »
Hi all
Am curently building webbots version of the 50$ robot micro controler. I realy liked the idea to design the board more universal. So far so good acording to PCB etching and soldering components but have a little question. Why on the PCB layout in the .pdf all ADC pins are shorted and on the schematics are not. Please excuse my lame questin as probably there is a good reason for that.
Thank you

Offline chelmi

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Re: Building 50$ robot Micro Controler Webbot's version
« Reply #1 on: April 20, 2010, 05:51:00 PM »
I noticed on your layout that you mention the ATMega 168. Please note that the Webbotlib barely fits and you won't be able to do much with the remaining memory.


http://www.societyofrobots.com/robotforum/index.php?topic=10760.msg81754#msg81754

Offline Webbot

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Re: Building 50$ robot Micro Controler Webbot's version
« Reply #2 on: April 20, 2010, 07:46:51 PM »
@chelmi - 'huevon' is talking about my $50 Robot PCB design - not WebbotLib. ie its a hardware question - not software.

Its the ground pins on the headers that are all connected together, and the power pins are all connected together, the signal pins are not shorted.

The ground pins are the outermost, then the power pins, and the signal pins are innermost.
Webbot Home: http://webbot.org.uk/
WebbotLib online docs: http://webbot.org.uk/WebbotLibDocs
If your in the neighbourhood: http://www.hovinghamspa.co.uk

Offline Razor Concepts

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Re: Building 50$ robot Micro Controler Webbot's version
« Reply #3 on: April 20, 2010, 07:55:14 PM »
I'm looking at the attached PDF and 6 signal pins are shorted together where the headers are?

Offline chelmi

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Re: Building 50$ robot Micro Controler Webbot's version
« Reply #4 on: April 20, 2010, 08:11:47 PM »
@chelmi - 'huevon' is talking about my $50 Robot PCB design - not WebbotLib. ie its a hardware question - not software.

Woops, my mistake :p

Offline Webbot

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Re: Building 50$ robot Micro Controler Webbot's version
« Reply #5 on: April 20, 2010, 09:17:00 PM »
I'm looking at the attached PDF and 6 signal pins are shorted together where the headers are?

Yep - you are right ! What the ..!  I have built this board and it works just fine. Eagle seems to be making the pads too big and hence they 'short'. Perhaps its got clobbered by different Eagle versions.

Will fix and upload a new version

EDIT: Aaarghh Eagle must be the most unfriendly program on earth! How can I change the header pins to leave them where they are and just change the pad size???? Their existing pad size is not friendly as it means any rows of headers at 0.1" pitch will create shorts !!
« Last Edit: April 20, 2010, 10:12:36 PM by Webbot »
Webbot Home: http://webbot.org.uk/
WebbotLib online docs: http://webbot.org.uk/WebbotLibDocs
If your in the neighbourhood: http://www.hovinghamspa.co.uk

Offline huevonTopic starter

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Re: Building 50$ robot Micro Controler Webbot's version
« Reply #6 on: April 21, 2010, 02:46:02 AM »
Quote
Will fix and upload a new version
So sory for the headache I'm giving you Webbot.
Thank you all for your replies, it will take just few min to separate the pads :)  On the PCB I mean, don't know how is done in eagle. In fact the PCB layout is very clearly designed and well optimized. If you don't want just to build the 50$ robot and finish with the robotics I recommend building Webbots version of ATmega MCU. It is a good electronics project and you can use it in the future to control even more servos. If you already have some equipment at home and spend money for the components only it will hardly go over 20.

Quote
I noticed on your layout that you mention the ATMega 168. Please note that the Webbotlib barely fits and you won't be able to do much with the remaining memory.
Rasor Concepts do you think there will be enough memory for webbotlib if I use ATmega 328 instead of 168?

Offline Webbot

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Re: Building 50$ robot Micro Controler Webbot's version
« Reply #7 on: April 21, 2010, 03:53:50 AM »
Yep the 328P is much better - and not much difference in price.
Webbot Home: http://webbot.org.uk/
WebbotLib online docs: http://webbot.org.uk/WebbotLibDocs
If your in the neighbourhood: http://www.hovinghamspa.co.uk

Offline Razor Concepts

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Re: Building 50$ robot Micro Controler Webbot's version
« Reply #8 on: April 21, 2010, 04:08:05 AM »
I personally use the sparkfun library, they have the smaller circular  headers instead of the longpads.

Offline huevonTopic starter

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Re: Building 50$ robot Micro Controler Webbot's version
« Reply #9 on: April 21, 2010, 05:37:17 AM »
Quote
Yep the 328P is much better - and not much difference in price.

I found some in www.coolcomponents.co.uk for £2.25 each(may be about $3.70). I find them pretty inexpensive, but what the experts think?

P.S
hehe someone will have to write a special tutorial for me how to use quotations in the SOR forum :P
« Last Edit: April 21, 2010, 05:41:23 AM by huevon »

Offline Webbot

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Re: Building 50$ robot Micro Controler Webbot's version
« Reply #10 on: April 25, 2010, 10:37:29 AM »
@huevon

Got round to posting a new zip file with 'no overlaps'. Also added a PDF of the Top view.

When using the PCB pdf don't forget that depending on which PCB method you are using then you "may" need to 'flip' the PDF over to create a mirror image
Webbot Home: http://webbot.org.uk/
WebbotLib online docs: http://webbot.org.uk/WebbotLibDocs
If your in the neighbourhood: http://www.hovinghamspa.co.uk

Offline huevonTopic starter

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Re: Building 50$ robot Micro Controler Webbot's version
« Reply #11 on: April 25, 2010, 03:12:40 PM »
Cheers Webbot
I actualy had etched the PCB before writing in the forum using toner transfer method but noticed the shorted pins before soldering. Easely fixed the problem with a paper knife after you confirmed my worry. Now everything is soldered in place and can't wait for my programmer to arive.
Any way you have done realy good job which helped me a lot.
Big thanks to all sor members as well

 


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