Stingray programming troubles

2pietjuh2

Hey everyone,

I'm quite new to programming, and this parallax unit. We are working with a lot of people from school on about 12 stingray robots.

We made a program to control te DC motors to drive the stingray, which works.

We can read our line sensors, they work fine too.

But, if we make a program reading our line sensors and controlling the DC motors with our own build program it is doing completely random things we dont want.

Does anyone know what we are doing wrong?


Thanks for the help!

2pietjuh2

UPDATE: removed code from this post, and added it in an archieve as desired
linefollower - Archive [Date 2011.05.11 Time 20.19].zip

2pietjuh2

does anyone know where the problem could be?

Roy Eltham

That repeat is not in a good place, and the function geval is never called.

This code doesn't even look like it would compile correctly. You use PST but it's not in the OBJ section.

Microcontrolled

What is the local "line" variable used for in the first PUB routine of the main program?

The reason it doesn't work is because you don't ever call the getval routine from the Start routine. The program stops instantly unless you type "getval" at the bottom of the start routine I don't exactly understand the repeat loop either.

StefanL38

Hi 2pietjuh2,

and welcome to the propeller-forum

You should attach your complete code to a posting.

This is easy to do with the archive function of the propeller-tool

In the propeller-tool activate that tab that contains your main program

From the main-menu choose File - Archive - Project ...
This will create a ZIP-archiv that contains all files needed to compile your code.

Use the Go advanced button bottom right of the website to change to the advanced posting website.
Click on Manage Attachments and upload the ZIP-archiv.

Then we can analyse the whole thing.

best regards

Stefan

2pietjuh2

Hey,

Thanks for your reactions!

I attatched an achive with the full code. Hope someone can help me

Thanks ,
2pietjuh2

StefanL38

Hi,

I tok a quick look into the code.

I'm not familiar with the pwm_32-object.

So I can do only a guessing. maybe switching on/off the motors just with 50% is too raw and maybe the repeat-loop is running too fast.
But that's just a guessing.

So what changes if you insert a waitcnt-command of 1 second or 0,1seconds?

How is the line-follower-sensor connected to the propeller?

best regards

Stefan

2pietjuh2

Thanks,

I will try that waitcnt-command for 0.1 second, if i try more i think I'll lose my line...

The line-follower-sensor was originally not for the stingray. But we switched 2 cables on each sensor and connected it to pin 0,1,2,3. This was on advice of our teachers. When using the parallax serial communicator and right code it responded as expected. but when we change the code a little bit, (in this case to eg. PWM.motor(1,0,50)) it wont work anymore...

hope I made my problem clear.

Thanks for any help!

2pietjuh2

John Abshier

Your problem is not clear. You say the line sensor is connected to pins 1,2,3 and 4, but the code in linefollower.spin only reads pins 0 and 1. I recommend the following. Put the Stingray on something so that the wheels almost touch the ground. In each of the if statements put in a write statement to identify what the line sensor sees. You can then see if the line sensor sees what you think it sees and compare motor movement to the debug write statements.

John Abshier

PS. If I understand the code correctly, the PWM frequency for the motors is 60 Hz. Where did that come from? It looks low.

2pietjuh2

Hello John,

I changed the pins, made a mistake in prev post.

About the write statement, we did that. And that works. But it stops working when we change the write statement into something else.

So we can log in the terminal the output of the sensors (eg 1111 or 1010). But to start with, we used only sensor 0 and 1.

thanks,

2pietjuh2