newbie HERE

[don bunot]

hi im a newbie here, and also in robotics and just want to share my project its a MINI sumobot,

im currently using an pic16f877a microcontroller and also im a using a TWIN MOTOR ,

but i have a slight problem on applying my speed controller to my project.

do you guys have any idea..

inputs would much be much appreciated,.

thanks in advance.

[Conscripted]

Welcome! Can you be a little bit more specific on what your problem is? We will need more information before we can help.

Conscripted

[waltr]

Yes, we do need more info.

What Motor driver are you using? The PIC can not drive to motor directly so you need at least an H-bridge.

Post a link to any motor drive and motor you are using so we can easily look at the data sheets.

What sensors are you using?

I have used PIC16F874 (28pin version of the 877) for a differential drive Bot. The 877 will easily do everything needed on a Sumo bot.
Which programming language are you using? Assembler or C?

[don bunot]

im currently using a toshiba TA7291s,.

heres the data sheet . http://pdf1.alldatasheet.com/datasheet-pdf/view/31275/TOSHIBA/TA7291S.html

im using a PNA4602M http://www.datasheetcatalog.org/datasheet/panasonic/SHE00044AED.pdf

for my micro controller ive tried to use pic16f877a.

for my programming language. im planning to use MikroC in which im not very good at programming. 

and very desperate to have my project done by FEBRUARY.. :'(
 

[waltr]

Ok, the motor driver IC is for one motor so you will need two of them for two motors. IN1 & IN2 would be driven from the PIC. This Chip does not lend itself well to being PWM speed controlled by the PWM hardware module of the PIC due to needing to toogle two inputs.

The IR sensor requires a modulated IR light source of 38kHz. This sensor is commonly used for TV remote controlls and there is lots of info on the web on using these for Bot sensors and other purposes.

I don't know much about MikroC as I use HiTech C compiler and the MPLAB IDE from Microchip.

very desperate to have my project done by FEBRUARY

And you first posted mid-way through February!!!!!

What have you gotten done?
Post the schematic you have and any code written. We'll try to help but remember this is not 'desperate' for any of us.

If you haven't started and have never written code for PICs then I'll estimate that if you work on this for several hours a day you could have the project done in a couple of months.

Good luck.

[waltr]

Got your PM and posted it here:

hi walter thanks for the kind replies, ive used 2 motor drivers. but i dont know if i am using the right ic to put pwm on my program to work on,.. pls i need some expert advice.,. im still a newbie, anyways deadline was pushed till 2nd week of march.

and i hope to fininsh this the soonest,.

i dont know about about speed controllers and how to manipulate them, but if i can put speed controller on my sumobot w.o using pwm and the hassle of programing it, then i thinks its already been done,. or im done with the project.

i was thinking of voltage divider if it is possible to drive as speed controller,.

i will post here my schematics and my ckt on sensors. as i have used 2n222a for my sensors and 555 timer to produce 38khz of fixed frequency to detect my object.

looking forward to chat with you again man,.

cheers,
DON

A voltage divider will not work for speed control with the driver chip you have.

I'm now thinking that you may not need any speed control for a Sumo Bot. Just go, stop, reverse, turn right, turn left. This would be easy to program and help in meeting your deadline. So for now forget about using PWM and just use the logic table in the motor driver data sheet.

Get the motors and driver chip wired and start testing. Look at some of the other recent threads here any other issues.

The other complication with speed control is the feed-back requirement. Save this for another Bot.

I have used those 38kHz sensors on a Bot for object detection and they do work well. Hint: I adjusted the distance of detection by adjusting the modulated IR LED current (LED's series resistor value). Another is shielding the sensor from the IR LED or shielding the IR LED. You want the sensor to only 'see' the reflected IR LED light.

How is the coding on the PIC going?

[don bunot]

still having some problems on the coding waltr.

yep ill try to use the logic table thats present on the said IC.

thanks for the replies though.

appreciate it much buddy

[Admin]

hi don bunot

It's not entirely clear to us what your robot has working already, or what isn't working properly. We need more information.

Are you saying you don't have any code at all, and don't know where to start?

Have a look at my HyperSquirrel robot.

It uses a PIC16F877, and a L298 Dual full bridge driver IC (a motor driver). You will have to tweak it a bit to work with your motor driver. You can download my source code here.

[Razor Concepts]

Admin... digging up an old thread? 

[Admin]

Admin... digging up an old thread? 

oops . . . I must have mis-read the date

(bad admin, bad! don't be like admin! lol)

[don bunot]

thanks admin,.

im trying out servo motors instead of twin admin

[don bunot]

"SUMO BOT with Speed CONTROLLER" using PWM pulse.

whew! i never thought i can never access my account again, so here is the UPDATE.

my PROJECT has been DONE. last MAY 2011(Which works perfectly), and I Graduated from my Computer Engineering Course.

i was soo busy with work. and i forgot to CLOSE this THREAD and FINISH what i Have started.

and later i will post here my Finished Product of my Project. Pictures, VIDEOS, Circuits, PDF and all Files that

Describes my said Project. but right now i still have to find my OLD files on my hard drive.

Thanks Everyone.
Don.

[waltr]

Ok Don, that is great news. Congrats.
Thanks for the update and am looking forward to the pictures, etc.

[don bunot]

HI walter. yeah. so this is it.

 

[don bunot]

MORE PICS..























whew! photos..

PM me for the VIDEO LINKS.

as i am running out of time ciao for today..

cheers,
Don Rey

[waltr]

That Bot really looks good.
Nice flow chart of the PIC code that should be useful to others learning how to write code.
Thanks for the update.

[don bunot]

No Problem waltr,

yeah the flowchart is a great way to write codes for the PIC.

this is something that i have to post back to SOR,

as i have done my project before with some help of my friends and also proud of what i made, which also works great.