Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: JDeschambault on March 26, 2007, 08:25:11 AM

Title: Building my own PCB some Advice Please...
Post by: JDeschambault on March 26, 2007, 08:25:11 AM
I am going to build my Own PCB and am wondering what are the few things i should have on even board i build. Of course it will depend on what i am building. here is my next Project... 2 to 4 motors, up to 10 servos and communication with 3 other boards...
Title: Re: Building my own PCB some Advice Please...
Post by: dunk on March 26, 2007, 12:27:27 PM
so first some questions:
do you have a circuit in mind?
have you prototyped that circuit?

if you can't answer yes to both those then you almost definitely don't want to build a Printed Circuit Board yet.
start with a breadboard: http://www.iguanalabs.com/breadboard.htm (http://www.iguanalabs.com/breadboard.htm)
once you have a working circuit move on to stripboard or perfboard. http://www.societyofrobots.com/robotforum/index.php?topic=685.0 (http://www.societyofrobots.com/robotforum/index.php?topic=685.0)
many (most?) people leave their projects on stripboard or perfboard permanently as there is little real advantage to making a PCB once you have a working prototype.

dunk.
Title: Re: Building my own PCB some Advice Please...
Post by: JDeschambault on March 26, 2007, 03:54:41 PM
I have been using the Basic Stamp Homework Board, but i need more... The project i have in mind as you can see is a little bigger then what it can handle. I am just trying to figure out what i need... I.e. The Basic stamp board has a microcontroller, EEPROM, a clock... etc. I have used this board for my first couple of Robots, but i am ready to up grade and build my own board. jsut wondering what it might need.

I plan on using a perf board dont get me wrong, i am just trying to figure out what to put on the board.
Title: Re: Building my own PCB some Advice Please...
Post by: dunk on March 26, 2007, 04:32:10 PM
ah, got you.
ok, so do you intend this to be an add on for your basic stamp board or are you planning on programming your own microcontroller?

if you are building this without your basic stamp the microcontroller is proably the trickiest bit to decide upon.
everyone has their own opinions on the best one to start with but if you are looking for a "just the chip" type project, either an Atmel AVR or a Microchip PIC probably best suits you best.
the PICs have the advantage of having being on the market for some time so there is a large user support base of hobbyists using them in the internet. the down side is you will need to buy a (relatively) expensive programmer for them.
AVRs on the other hand are newer, come with free C compiler and can use a simple inexpensive cable for programming.
i won't go on about these 2 any more. try searching this forum for "PIC" and AVR". this has all been discussed before.
you can expect to pay under $5 for a microcontroller chip on it's own (either AVR or PIC).

after that a voltage regulator circuit to give you a nice clean 5Volts is a good start. (search the internet for "LM7805" voltage regulator.)

motor drivers will be usefull as motors will draw too much current for your chosen microcontroller to handle. (maybe the basic stamp has these built in?) you can either build your own from "MOSFETs" arranged to form an "H bridge" or buy an off the shelf motor controller IC.

have you seen Admin's $50 robot tutorial?
it might answer a lot of the questions you have: http://www.societyofrobots.com/step_by_step_robot.shtml (http://www.societyofrobots.com/step_by_step_robot.shtml)

happy building,

dunk.
Title: Re: Building my own PCB some Advice Please...
Post by: JDeschambault on March 26, 2007, 04:38:36 PM
As a matter of fact i jsut found and read the step 3 Brains building... So if i want it to be reprogrammable i dont need the EEPROM?  or will i want to add that on there?