THIS ARTICLE IS NOT READY YET! I'LL START FINISHING IT AS SOON AS I'M DONE WITH MY BOARD EXAMS

AT 31 MAY! UNTIL THEN BE PATIENT! AND WISH ME GOOD LUCK WITH MY EXAMS...

 

 

IF YOU WANT HAVE A LOOK AT THE DS2438Z SMART BATTERY MONITOR. WE ARE COMING BACK WITH

A BETTER VERSION AND A MODULE READY TO PACKED WITH A BATTERY PACK MONITORING VOLTAGE

CURRENT IN AND OUT (meaning that you can track both battery life circles and charging) TEMPERATURE

AND EVEN PROVIDING SOME STORAGE FOR DATA...

 

THANKS FOR YOUR PETIENCE...

 

It's been a while I was using only my Basic Stamps for building robots... But Basic Stamps lack both the speed and the flexibility for most applications even though the are perfect for learning structured programming and the BASIC language. So now the time has come for me to use AVR in my robots... AVR are nice microcontrollers with many features, like interrupts, timers and so on..., they are much faster that the Basic Stamps and the have bigger memory allowing us to write more code... Also they are very easy to use requiring only power to operate (and if you like a crystal - osclinator) and very easy to program (There are many nice circuits out there in Google... I just prefer the 10pin STK500 ISP). So in this project we'll be using the ATMEGA16 @16MHz. But as every project... it must have something special, something to be able to look different from other... But what???

I 've seen many robots with photosensors (photovore, photophobe), many linefollowers, many object avoiders, some heat seakers, sumobots, micromouse and others... BUT, very few had a battery monitor... Most of them run on a new or freshly recharged battery... If the battery was drained and wasn't simply enough capasity to feed the robot???

That's why I incorporate a Dallas Semi DS2438 in my circuit board... I don't like usually to advertise but this chip had everything... A current sensor, a voltage sensor, a thermometer and so other goodies we won't be needing...

 

Now navigation... Since it'll be a simple navigator - free roaming robot (with some extra features) I'll be using a simple IR_pair for the robot, but if I have time (aaa exams exams exams exams they are killing me!!!) I'll also include a Sonar... The pair will consist of a TSOP1907 and some single IR Leds...

 

And now it's picture time... Since I have assebled the case years ago and don't like to rip it up right now... I'll be showing some basic pictures of the case of the robot explaining how it was built and which are the thoughts for the future =P....

So here is an overview of the robot case:

 

And here is the front view of the robot... As you can see the case is quite close to the ground but our subject here is not machining clearly but programming the robot behaviors...

 

Here is the bottom view of the robot... It used to be used as a place for the batteries but as experience grow it teaches me to place the battery (and any other heavy thing) in the front of the robot to be able to climb hills with easy... But more details coming...

 

And here is the machining tips for the wheels!!! I got some servo cross-like horns cutted 'em to fit the inner of the wheel, placed a screw in an empty hole of the wheel and glue it for safety with some super glue!!! And finish... Also I kept the outter axis of the wheel (it was there from the time I bought this poor toy) and after shorting it a little, I fitted it back in. So the Case and the wheels are bond together making the locomotion system more stample than ever. NOTE: that the locomotion system that was with the toy was extremely weak that's why I placed in the servos!!!

Finally, and also very important, after mounting the servos to the case I jointed 'em with that golden pipes (don't know how to call 'em sorry). And here we are... the locomotion system and the case in finished!!! Now it's batteries' time...

 

And now the hardest part for me... mounting the batteries... Batteries usually are the heaviest part of a robot. Because we have a tracked robot, placing the batteries in the front is crusial for the balancing of our robot and it's ability to climb step hills!

 

By placing the batteries that way:

 

I hane the robot balancing it's weight at about the middle of the robot so it's just very ok!!! As you can see the holder is very simple just a part of a pcb mounted to the case with some screws and glue and so long pin headers to hold the battery. So with the battery, it should look like that:

 

 

And now the big deal... The electronics. I have been trying to use two microcontroller since the beginning but always something was about the fail... LCD fail, IR fail, frequency generator fail... And do on which I really hate to describe (my hours being lost for nothing). And the biggest of my problems... That f*ckin# TSOP were broken, they were old - yes, but broken??? AAggghh!!! All my Sunday for a pretty nothing... Uugghh, sorry for this but I think everyone can understand me... So, finally, I had 'em replaced with some nice Panasonic ones I had... (desoldered 'em from older boards I have made and almost never used...) Surpassing these promblems after many hours having been wasted I finished the main board consisting of a ATtiny2313 @ 20MHz that I won't refer to cause it's never used, the main processor which is an ATMEGA16 @ 16MHz, a simple regulation circuitry, a NE555 tuned at ~38KHz for the IR leds and the pride of the board! The DS2438!

Before I get any closer to the software I'll give the schematics...

 

So here are the schematics for the main board of the robot:

 

The regulation circuit consist of a simple 7805, some filter capacitors and some anti-current spike capacitors

And here it is:

And now the NE555 schematics:

So after all these the board should look like that:

 

And finally the board mounted on the case!!! I feel just nice...