Author Topic: IR sharp rangefinder (Read 7189 times)

maverick monk · « **on:** January 14, 2008, 02:54:39 PM »

hey, its me again... sorry guys ive been a bit of a pest with this. but... my major accomplishment

the robot runs in a strait line...

the drawback...

thats all it can do

I need your help with 3 things.

what is the exact code in C to gather a value from my sharp IR range finder
how do I convert the number to volts and then to feet or inches???
how do I make my robot turn its servo 45 and 90 degrees left and right??? Ive looked at the things on the arduino playground and they are confusing the crap out of me, please help, i have till the 20th to get this thing working

maverick monk · « **Reply #1 on:** January 15, 2008, 02:44:22 PM »

anyone?? please guys i need some help with this. I searched but I cant find anything.

bukowski · « **Reply #2 on:** January 15, 2008, 02:54:27 PM »

just use the code off the $50 robot tut.

SmAsH · « **Reply #3 on:** January 15, 2008, 03:16:56 PM »

or if your terrified of microcontrollers like me use the $40 robot

maverick monk · « **Reply #4 on:** January 15, 2008, 03:54:12 PM »

smash, the robots done dude... i just need to program it...

new error, im using the arduino programmer and i got this

hardware\libraries\servo/avrlibtypes.h:70: error: expected unqualified-id before numeric constant

Couldn't determine program size: C:\Documents and Settings\Nick.GATEWAY\My Documents\winavr\arduino\arduino-0010\hardware/tools/avr/bin/avr-size: 'C:\DOCUME~1\NICK~1.GAT\LOCALS~1\Temp\build14969.tmp\forward_reverse.hex': No such file

maverick monk · « **Reply #5 on:** January 16, 2008, 05:49:32 PM »

sorry for double posting like this but my deadline is comming up FAST! need some help. thanks in advance

DomoArigato · « **Reply #6 on:** January 16, 2008, 07:23:48 PM »

What chip are you using? ATMega168? What part of the programming is making it difficult? The software, or just loading it on? To get input from the IR Rangefinder you have to use the ADC on the chip. To output to a servo, you'll probably want to use the Timer in PWM mode. I have some code for the 128 if it would help.

maverick monk · « **Reply #7 on:** January 16, 2008, 07:25:39 PM »

i get that error every time i test it to see if it works, it cant find the hex file in the temp folder

DomoArigato · « **Reply #8 on:** January 16, 2008, 10:45:59 PM »

I haven't actually made the 50$ robot. So I'm not sure how much I can help you. Does the code compile with that numeric constant error? Is there a hex file in that directory where the programmer is looking or is it failing to build the hex file because of the compile error? C:\DOCUME~1\NICK~1.GAT\LOCALS~1\Temp\build14969.tmp\forward_reverse.hex You may have more luck if you start a topic like "Trouble loading hex file onto Arduino" so people with experience there will open up the thread.

Admin · « **Reply #9 on:** January 17, 2008, 09:27:30 AM »

To use the sharp IR, you just need to read the analog pin.

Code: [Select]

IR_value = analogRead(0);//use pin 0 for analog
for servos, do something like this:

Code: [Select]

digitalWrite(13, HIGH);    // turns port 13 on
delay(120);                  // delay determines servo speed/position
digitalWrite(13, LOW);    // turns port 13 off

I don't know exactly what delay will work, so guess some values between like 30 and 300 until it works.

maverick monk · « **Reply #10 on:** January 17, 2008, 05:12:50 PM »

thanks for the help but, How do i find the right integer for my IR, its always enabled it seems

void setup()
{
}
void loop()
{
int IR_value;
int IR_Loop;
//Forward Motion
digitalWrite(2, LOW); //lReverse
analogWrite(3, 255); //lForward
digitalWrite(4, HIGH); //lEnable
analogWrite(5, 0); //rReverse
analogWrite(6, 255); //rForward
digitalWrite(7, HIGH); //rEnable
delay(20);
digitalWrite(2, LOW); //lReverse
analogWrite(3, 0); //lForward
digitalWrite(4, LOW); //lEnable
analogWrite(5, 0); //rReverse
analogWrite(6, 0); //rForward
digitalWrite(7, LOW); //rEnable
delay(20);

IR_value = analogRead(1);//use pin 0 for analog

if(IR_value <=110)
{
digitalWrite(2, LOW); //lReverse
analogWrite(3, 255); //lForward
digitalWrite(4, HIGH); //lEnable
analogWrite(5, 255); //rReverse
analogWrite(6, 0); //rForward
digitalWrite(7, HIGH); //rEnable
delay(2000);

}
}

when it turns on it goes strait to the if block and wont leave, no matter what i make the IF statement, what am I doing wrong?

Admin · « **Reply #11 on:** January 17, 2008, 06:12:14 PM »

This is because your delay values are totally off . . . and that you aren't doing proper servo control:

turn port on
delay
turn port off

Don't try to do everything at once, just try to get one servo to change directions first.

When that works, then add the sensor, then the other servos.

This makes debugging much easier. Try a delay of like 220 and see what happens.

maverick monk · « **Reply #12 on:** January 17, 2008, 06:28:33 PM »

thats not with the servo, thats with the hbridge, i just cant get the if statement right to get a normal threshold for the IR

paulstreats · « **Reply #13 on:** January 17, 2008, 06:43:26 PM »

okay, i have similar issues with C18 for pics. If I use <= or >= in an if statement it doesnt work, I need to just use < or > and then an else for the middle vale

maverick monk · « **Reply #14 on:** January 17, 2008, 07:11:19 PM »

ok, im not getting good readings from this thing, what could be wrong???

airman00 · « **Reply #15 on:** January 17, 2008, 07:21:48 PM »

connect an LCD to it ( if you have one) to see the values in real time

maverick monk · « **Reply #16 on:** January 17, 2008, 07:23:59 PM »

If i could pull a lcd outa my butt and programm it... thatd be great!, is there a way to printf the variable to the arduino programming environment in real time??? if so, how, (exactly how, im realy not so good at this yet)

paulstreats · « **Reply #17 on:** January 17, 2008, 08:31:27 PM »

I think the arduino has a max232 serial comms chip on board, you can just do a serial transfer with it if so. Use hyperterminal in windows to view the output. See admins uart tutorial for more info

maverick monk · « **Reply #18 on:** January 17, 2008, 08:46:11 PM »

why cant it just work??? can anyone help me diagnose this thing? i dont have time to do a uart thing with a serial port adapter or anything like that

airman00 · « **Reply #19 on:** January 17, 2008, 09:13:14 PM »

Quote from: maverick monk on January 17, 2008, 08:46:11 PM

why cant it just work??? can anyone help me diagnose this thing? i dont have time to do a uart thing with a serial port adapter or anything like that

You mean you dont have patience

.

Listen , knowing how to do UART is a very good skill to have . Learn it now!

paulstreats · « **Reply #20 on:** January 17, 2008, 09:31:07 PM »

okay,

so ive never used an arduino board, but i checked a tutorial just for you.....

Quote

IR_value = analogRead(1);//use pin 0 for analog

in this url http://www.arduino.cc/en/Tutorial/Knock
it uses analogRead(0) for pin 0 and not analogRead(1).

Could this be your problem?

frank26080115 · « **Reply #21 on:** January 18, 2008, 12:23:15 AM »

Quote from: paulstreats on January 17, 2008, 09:31:07 PM

okay,

so ive never used an arduino board, but i checked a tutorial just for you.....

Quote
IR_value = analogRead(1);//use pin 0 for analog

in this url http://www.arduino.cc/en/Tutorial/Knock
it uses analogRead(0) for pin 0 and not analogRead(1).

Could this be your problem?

You bet, and damn, I was reading the entire thread thinking nobody was going to pick it up.

I can see you are using something like an L298
You are supposed to use PWM on the enable pin, not the digital inputs

maverick monk · « **Reply #22 on:** January 18, 2008, 09:59:08 AM »

im using analog pin 1 instead of 0, hence the 1 instead of the 0, does that cause a problem???

the drive works fine, everything powerrelated is working fine but the sensor wont give me a good value. I realy dont have time to mess with uart, i need to have atleast a basic version (without sensor/servo sweep) working by tuesday. so,

do I need to use analog port 0? or can I use 1 like im doing now?
im assuming that whatever port im using goes in the ()'s. right?
or is it somthing else? like starting value or somthing... maby robotics wasnt a good idea for a sophmore highschool science fair... oops

edit!: it works... turns out sparkfun got the lables for their analog pins on the sheild kit backwards, i was pluged into pin 4 even tho it said 1 on the sheild (which covered up the origional kits markings...)

dont you love it when the small stuff doesnt work??? testing my code now,but im getting values from my sensor now

!

maverick monk · « **Reply #23 on:** January 20, 2008, 11:59:02 AM »

Ok, now i got the IR working flawlessly, thanks to all of your help. but no matter what I do the only way I can get the servo to go is to the right, how do I get it to go back to the left??? thanks in advance to any answers.

Bubbles · « **Reply #24 on:** January 21, 2008, 08:11:37 PM »

This should help you a bit with making the servos go the other way:

http://www.societyofrobots.com/robotforum/index.php?topic=2724.0

good luck!

maverick monk · « **Reply #25 on:** January 22, 2008, 05:37:18 PM »

ill try to figure that out,thanks, but now my robot keeps traveling in circles! wtf??? the code worked 2 days ago?

I hate this project...im trying to figure this out, but now my trax keep falling off and I need to build a tensioner

airman00 · « **Reply #26 on:** January 22, 2008, 05:46:28 PM »

Quote

OK tjpark11 I GOT IT , IT JUST POPPED INTO MY HEAD!!! Cheesy

BUY THE SAME SERVOS ( regular clockwise for both)

then when you get the servos , open one of them up and reverse the wires going to the motor . There you got one going clockwise and one going anticlockwise on the same pulse!

I just thought of this now and I'm going to be doing this for all my servos in the future. After I modify them , ill switch the wires of one of them so I have one universal pulse for forward and one for backward.

ADMIN PUT THIS IN YOUR SERVO MODIFYING TUTORIAL!!!

an idea which popped into my head today, I posted this response elsewhere on the forum

maverick monk · « **Reply #27 on:** January 22, 2008, 06:01:10 PM »

what does that have to do with anything???

im not using servo's for drive, im using a dualH bridge.

airman00 · « **Reply #28 on:** January 22, 2008, 06:29:16 PM »

oh sorry I thought you were using servos

so how is it going in circles, one going forward one backward or just one forward

maverick monk · « **Reply #29 on:** January 22, 2008, 07:22:35 PM »

it doesnt go in circles anymore... the track gears stripped and I had to make some bs wheels (hot glue and rc car wheels) now it doesnt seem to have any formal thought at all... it just does whatever, whenever, i think the sensor might be getting junk readings. but im realy begining to HATE THIS THING!

btw... i got 54 hours to get this thing working, aproximatly

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Author Topic: IR sharp rangefinder (Read 7189 times)

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