encoders

[stephenthe1]

is that already in the default routine, because our compressor doesn't automatically turn itself on. plus, if you read my above post, are you sure the default settings work with the way my bot is configured? thank you.

[gnormhurst]

I have some vague recollection that you may not pass inspection if you do not have the pressure limit switch controlling the compressor.

Last year we were overweight and removed our compressor, opting instead to charge the air tanks before each match.

[thoughtful]

Sorry if this is a bit off topic.

I was looking through the encoder the Mr.Kevin provides on his website. I did not find the model of the encoder he was using, i am currently wanting to use optical encoder from digikey there a lot of them available. I am trying to decide which one to buy and will the optical encoder just tick when the dark area changed to light?

Thank you in advance

[Kevin Watson]

Originally Posted by thoughtful

...I was looking through the encoder the Mr.Kevin provides on his website. I did not find the model of the encoder he was using...

From the readme.txt: "This software was tested with Grayhill 63R256
and 61K128 quadrature output optical encoders. Data sheets for
these devices are included."

-Kevin

[CJO]

As Anthony points out. If you have power to burn, leave the compressor in full auto, if, on the other hand, you want manual control (for any one of a number of reasons) I think that the wheel is a good choice, as it is convienient, and hard to press by accident.

[Anthony Kesich]

Originally Posted by gnormhurst

I have some vague recollection that you may not pass inspection if you do not have the pressure limit switch controlling the compressor.

Last year we were overweight and removed our compressor, opting instead to charge the air tanks before each match.

I believe it is the pressure blow off valve that cannot be removed, not the pressure sensor. In 2003, we ran without a sensor. That's where CJO got the code from. We used the wheel since we didnt have any more buttons on the controller to map the function to. We controlled it manually since we were having power regulation problems and decided to kill the compressor completely for the last 30-45 seconds of the match.

-Tony K

[roboticsjenkins]

How do I hook up th encoders to the RC. I know that they go on Digital I/O, but do I use two PWM CABLES to hook each encoder up or what do I do? Someone please help me.

[stephenthe1]

ok, I'm assuming you have a quadrature encoder (this means there are 4 places to hook up wires on the encoder). 1 is the + power pin. 1 is the - (ground) pin. one is the phase -a pin, and one is the phase b pin. this requires two digital ports on the rc. I'm assuming you are using Kevin watson's encoder template (the only way to do this if your a beginner). hook up the +, -, and phase a wires on the digital io 1. then put the phase b wire on digital io (I think, but check the template read me provided b Mr. Watson) on digital io 6. this is how the "left" motor encoder, or w/e our using it for is hooked up.

don't feel too bad, I had this same problem about a month ago, I started a couple threads before I was able to understand it.

hope this helps,
Stephen

[roboticsjenkins]

Let me see if I have this right I have to hook one encoder to two different Digital I/O ports?...I'm so confused

[stephenthe1]

ok here it is, and yes, one encoder to two digital IO's. did you read what I said carefully? um, check to see if there are four pins on the encoder, if there are, then you need two digital ios. here-

dig. io 1 ------- phase a pin ------- positive power --------negative power

dig. io 6 ------- phase b pin (only, no power or anything here)

if this doesn't make sense, then you really need to go to the white papers section and read up on interrupts a little and on encoders, and read through the comments on mr. Watson's code. questions are fine, but really, after reading this, you shouldn't be having any problems.

[stephenthe1]

(didn't mean to sound mad ) came out that way I guess

[dmurdz]

Im working on my programming, when it comes to my code I do not know how to set up my interrupt handlers, is there demo code some where for this???

[Alan Anderson]

Originally Posted by dmurdz

Im working on my programming, when it comes to my code I do not know how to set up my interrupt handlers, is there demo code some where for this???

See http://www.kevin.org/frc/ for lots of example programs, many of which are complete drop-in modules. Scroll down to frc_encoder.zip for interrupt-based encoder code.

[dmurdz]

Sample code from Kevin on www.kevin.org/frc, the interrupts program, in file interrupts.c, there is a spot that says:

/************************************************** *****************************
*
* FUNCTION: Int_3_Handler()
*
* PURPOSE: If enabled, the interrupt 3 handler is called when the
* interrupt 3/digital input 3 pin changes logic level.
*
* CALLED FROM: user_routines_fast.c/InterruptHandlerLow()
*
* PARAMETERS: RB4_State is the current logic level of the
* interrupt 3 pin.
*
* RETURNS: Nothing
*
* COMMENTS: The PIC18F8520's RB4/KBI0 pin on port b is mapped to
* interrupt 3 on the EDU-RC and digital input 3 on the
* FRC-RC [108].
*
************************************************** *****************************/
void Int_3_Handler(unsigned char RB4_State)
{
// this function will be called when an interrupt 3 occurs
}

Is this the final code??? What do I need to add???

HELP!!!!!!!!!!!!!!!!

[Kevin Watson]

Originally Posted by dmurdz

Is this the final code??? What do I need to add???

It's just template code that shows you how to setup the interrupts. Check out some of the other examples that show you what you can do with interrupts.

-Kevin