Let's Make Robots!

How hard would it be to build an Arduino?

I recently assembled the Really Bare Bones Board, pictured below.  It's an Arduino clone in a smaller and more affordable package.

RBBBrevB_front_800.jpg

The board is $12, which is a great deal.  But I want to lower my costs as much as possible.  During a 3-hour car trip today my mind was racing with ideas for potential robots, and I began realizing that for the projects I want to do I'm going to need multiple embedded microcontrollers.  What's more, each microcontroller board will need different appendages ... some with their own voltage regulation, others with motor controllers, some won't need analog input, and some will need LED's while others won't.  I like the idea of having each board with its own specific functions and abilities, rather than wasting money on an all-around package with some things I don't need and lacking something I might need.

Anyway ... the point is that it might make more sense for me to buy ATMega168's with the Arduino bootlegger and make my own microcontrollers.  Problem is ... I'm not entirely sure how to do that ... so maybe you guys can help me out? 

Ok so here's what I know I need: The ATMega168 needs a steady supply of 5 volts.  That's easy enough to pull off with a voltage regulator and a couple of capacitors. Next up is the resonator ... which I have a fairly good understanding of.  I know what pins to connect to, anyway, which I guess is all that matters.  Next up is a test LED, which of course is super easy.  And lastly the reset button, which I'm sure I can figure out.

Other than that, though, I don't know what the microcontroller needs to do its thing.  Looking at the RBBB, I don't know what all that stuff does.  What are the two capacitors for, for example?  There are two 47uF capacitors and I don't know what they do.  Does it allow for analog input via a resistor-capacitor circuit?  What about that diode there?  Is that for blowback voltage?  How about those resistors?  And lastly ... I'm very embarrassed to say I don't even know what the blue thingies are.  I'm assuming they're capacitors, but I could be wrong.

Thanks for helping out a beginner!  Sorry for the big blocks of text ... there's just so much I still don't know!!

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Hi. I hooked up an uA meter and measured it for you. My arduino With one power LED, and 13pin led blinking consumes 25 mA. My SuperHiperMegaPowerMadeinChina V 6F22 NiMH accu is rated at 250 mAh (that of course isn't true - I guess it's really about 125 mAh - I guess I once checked it on my RC plane uC charger). Since batteries tend to have slightly larger capacities than rechargeable batteries, let's assume that a 9V 6F22 duracell will be 250 mAh indedd. This means you can draw 250 mA for one hour or  25 mA for 10 hours. Of course the actual time may significantly differ as the 25 mA current draw measurement was very inaccurate. Also other factors such as temperature have some influence here. Anyway according to these calculations you should expect a couple of hours from your battery. You may also power your Arduino of 4xAA pack, omitting the 5V voltage regulator (which wastes plenty energy) on the board. You may connect the 4x1.2 rechargeable battery pack 4.8V directly to 0V and 5V pins on the board (but 4x1.5=6V from non-rechargeable AAs through a diode which will give you 0,7v step-down) . There are many brands of AA rechrgble batteries with capacities of up to 2500 mAh. And that's of course 10 times more than you can get of a 9V batt. Such thigs as RF equipment, motors and servos dain quite a lot. So 9V batt would not be the best solution in this case. 

 

this is my setup of an Arduino on a breadboard and it is fully working, and I am able to program the chip directly using an FTDI cable
http://lab.guilhermemartins.net/?p=539

this is an implementation of the setup above
http://lab.guilhermemartins.net/?p=686