$50 Robot with AVR ISP mkII 6 pin

[Webbot]

Before I started building the $50 robot I thought it would be good to have some kind of circuit diagram or at least a check list of what needs to connect to what. Mainly so I could check my soldering, volatages etc etc. So thought I would post the attached PDF document (in a ZIP file) that allows you to turn on/off layers on the board to see what's what. Old news to most - but 'may' be good news to some.

[ed1380]

why havent i seen this before. this is great. IMO it should be added to the original tutorial. it would have solved so many questions on the forum

[garriwilson]

No question, admin has to put this in the tutorial. This is amazing. Admin IMO you should put this in the 50$ tutorial as soon as you see this. This will be very helpful. Thank you webbot this is a great contribution.

[arsenius]

Just wanted to say thank you also.  This is great!  Really helpful!

[Maltaeron]

WOW, this is impressive, I had trouble trying to figure out what all is connected to what, and I didn't even know that this was possible in a PDF!

[Parth]

This is great! I was worried about the connections for the $50 robot, but this is just so much simpler! I'm definately using this when I make the microcontroller. No doubt that Admin has to put this in the tutorial.

[quinacia]

Beautiful

Let me add my voice to the "this should be in the tutorial" chorus.

[Admin]

Ok, its been added as a link right under the colored dot schematic.

(debating how long it will take for all questions on the schematic to suddenly end up in this thread )

[svenny]

This way is much easier for me to understand! =D The dotted schematic didn't show where the other breakaways went... Do not know why that confused me.

Anyways, Appreciate your efforts for creating this! 

[goatfish]

did you do this all by yourself or did you have help from a program(obviosly Adobe to show it off)
i need to know,because i want to create a baord from this schematic and i need a program to change it into a pcb
http://www.olimex.com/dev/images/avr-pg1b-sch.gif

cheers goatfish

[Admin]

goatfish, Eagle is what I use to turn schematics into PCBs.

That schematic you posted was made in Eagle.

[Webbot]

did you do this all by yourself or did you have help from a program(obviosly Adobe to show it off)

I actually did it in Microsoft Visio which, with Acrobat Professional, then allowed me to save it as a PDF including all the 'layers'.

Eagle is what I use to turn schematics into PCBs.

Yeah quite right - but you won't be able to do it from my PDF - of course. This would mean having to re-create the circuit in Eagle - and perhaps someone may do this and contribute it to the community. Eagle is great for going to PCB but has no option, as I understand it, to come up with a layout on matrix board or strip board. Given that most beginners will be using that format then thats why I choose the sledgehammer approach to create a matrix board layout using whatever 'drawing' tools I had available.

Give me a few hours and I'll knock together an Eagle 5 schematic - which would then help to produce your PCB design.

[goatfish]

oh thank-you so much  ,i look forward to seeing that,i tried to make the board in eagle but it wouldn't let me auto-route it,because its the lite edition

[newbie]

i followed this schematic pdf, i found some problem:
1. is the 4xAA battery pack for the servo output?
2. is the 9v pp3 battery for the microcontroller?

i found the voltage at the servo output is lower than the voltage at sensor input, why? is this correct? 

[Admin]

i tried to make the board in eagle but it wouldn't let me auto-route it,because its the lite edition

The lite edition can do autoroute.

The only thing it can't do is really large boards, and more than 2 layers.

[Webbot]

i followed this schematic pdf, i found some problem:
1. is the 4xAA battery pack for the servo output?
2. is the 9v pp3 battery for the microcontroller?

i found the voltage at the servo output is lower than the voltage at sensor input, why? is this correct? 

Yes to both points 1 and 2. The 4xAA pack is effectiviely 4 x 1.2Volts so about 4.8V when fully charged.
The 9V PP3 battery goes to the microcontroller VIA the 5V regulator - so the controller gets 5v.

So the voltage at the servo may well be slightly lower. The difference is that the 4xAA pack can supply a higher currrent over a longer time frame. Whereas the PP3 is just feeding the controller and sensors - so doesn't consume nearly as much current as the servos do.

[Webbot]

i tried to make the board in eagle but it wouldn't let me auto-route it,because its the lite edition

The lite edition can do autoroute.

The only thing it can't do is really large boards, and more than 2 layers.

The 'free download' doesn't allow you to auto-route and hence my delay in posting an Eagle version. I've forked out for the 'lite' version license which then does allow you to do so. So I am should get a posting up fairly soon. Sorry for any delays.

[Webbot]

I don't pretend to be an expert at Eagle (this is my first attempt!). But I've attached the project, schematic and board files in the attached ZIP file.

This differs slightly from the standard $50 robot in that most I/O pins, except the Analogue to digital ports, have 2 x 3 pin headers. One using the +5v logic supply (for use with sensors etc) and another that uses the motor supply (for servos, DC motors etc).  These are anotated by having either (5V) or (M) respectively on the end of their name. I've also put in a separate header for the UART.  So its a bit more flexible, but requires more header pins (which are cheap). But you could always add them on an ad-hoc basis.

I've also tried to only use 90 degree angles in the design of the board - so that people using stripboard/matrixboard etc should hopefully be able to use it. As should people who can only create a single layer pcb (most of us?). So the bottom layer (blue) is the pcb tracks, and the top layer (red) can be done with bits of wire soldered onto the top of the board. As a result I've ended up doing the 'auto-routing' by hand - and it has taken me forever - so I hope someone finds it usefull !!!!

If you know what you want your I/O pins to do, and they'll never change, then you may be able to delete the superfluous stuff and generate a 'tighter' board. But I'm still pretty pleased with the result. My only addition may be to add a power switch (which is why there is a gap between the 9v battery and the regulator).

Let me know: cool, sucks, or otherwise !! Am sure you will.....



 

[Admin]

I promise you, auto-route works in the free version:
http://www.cadsoft.de/freeware.htm

Auto-route doesn't do the best of jobs, but it can find a valid solution. I usually go back over many of the traces by hand, anyway. For my Axon, I did 90% by hand 'cause I can do better

[Webbot]

Their help file says:

The integrated Autorouter can be started from a board window with the AUTO command.
Please check your license to see whether you have access to the Autorouter module.

Which implies you need some sort of license.

When I tried it before ordering a single user license it just said 'Not available in the freeware version' (or something like that) - but after loading the purchased license key it now works.

[goatfish]

lol,been 2 lloooong months since i have been on here,the board didnt open in my version of eagle

[Webbot]

lol,been 2 lloooong months since i have been on here,the board didnt open in my version of eagle

I used Eagle 5.1.0

[Webbot]

Ok. Here's my latest bunch of files - including Eagle board and schematic files, Eagle 3D image (yeah - I know its missing the switch), a PDF of the PCB, and a photo of the board underway.
You may choose to implement the switch or not. I've used a double pole switch that controls the 9v battery back and the motor supply. So a word of caution:- if you are using larger motors then make sure the switch can cope with the amount of current that your motors are using. I'll probably be posting a tutorial about creating my PCB for the $50 Robot as I've learned a lot.

[kotentie]

Wow very sweet thanks.

[goatfish]

yea nice,but one slight prob,i was wanting the programming cable board made,not another version of the robot brains,sorry if you got confused,but nice work anyway

[frodo]

admin, you said a link is put under the colour dot schematic but that link comes back to this discussion. What is the circuit schematic link?

[Razor Concepts]

It is an attachment on the first post 

[Webbot]

I'll probably be posting a tutorial about creating my PCB for the $50 Robot as I've learned a lot.

So here's the tutorial that takes you through building the board (although the hints for building and testing as you go are applicable to most projects)

http://www.societyofrobots.com/member_tutorials/node/190

[Webbot]

There's actually 2 main attachments if you scroll through and look at my posts:

1. The first post has '50 buck bot.zip' which includes a PDF showing the $50 Robot built on the same board as used in Admins tutorial

2. A later post has '$50.zip' which contains an Eagle schematic for designing your own PCB - if you have the materials to do that.

[Metal Slug 2]

wow, thanks Webbot!  your diagram was simple and easy to read.  i was able to check my wiring in nearly half a minute.