Rookie help

doyler · December 20, 2004, 1:57pm

I am new to programming and extremely new to a lot of mechanical stuff in general, so my team gave me something to work on over the holidays, but I am very confused.
I will try and be as specific as possible to receive help

They gave me an edubot controller, a battery, a charger, 2 servos, a serial to usb converter, and something called a BEI GyroChip

I know what the battery, charger, and serial -> usb cable do/are for, but how would i hook up the rest of thie stuff to the control

Thanks

Mark_McLeod · December 20, 2004, 2:52pm

The servos plug into any PWM available on your controller. Setting the value (0-254) of the PWM will turn the servo to a particular spot. The same spot everytime you use a particular value.

The gyro plugs into an analog input on the controller (one of the first inputs based on User_Initialization() in user_routines.c). If it doesn’t already have a connector attached you’ll have to make one out of a PWM cable. You get values from it doing something like “x = Get_Analog_Value(rc_ana_in01);“ The neutral position of the gyro will be close to 512. When the gyro is twisted slowly in one direction you’ll get numbers between 0 and 512 only while you are twisting it. Do the same in the other direction and you’ll get numbers between 512 and 1023. If you keep track of these numbers you can tell if your robot is driving straight or not and correct. It can also be used to make precise turns, to say 45 degrees if you calibrated it.
This particular gyro is no longer “street legal” to use on your competition robot, but it’s good to learn with. This one will be overly sensitive to turns or sudden movements that are too quick, and will more easily lose track of the original robot heading.

Do a search on “gyro” for a lot of threads on the subject.

doyler · December 20, 2004, 3:14pm

the gyro has a pwm, and my only job is to make the sensors move or something

sensors go to pwm out? if so, the black is on top right
the gyro goes to analog in with the black on botton?

if all this is correct thank you and i will probably have questions later about what all these do and what / how to code

Mark_McLeod · December 20, 2004, 3:21pm

Yes, black on the outside, or the pin furthest from the controller, of each connector.
The gyro is a sensor and the servos are specialized motors.

doyler · December 20, 2004, 3:30pm

um, i have 4 pwm out pins, but only three holes, does the closest one not matter for these servos?

Mark_McLeod · December 20, 2004, 3:33pm

Leave the inside pin unconnected. It’s a duplicate power pin.

doyler · December 20, 2004, 3:41pm

I can use any 2 pwm out pins right
And I just put the gyro in the first digital in spot

Mark_McLeod · December 20, 2004, 3:47pm

Yes, any pwms will do for the servos.

If you are starting with the default EDU code, that arranges for the first two inputs to be analog, so either 1 or 2 will work.

doyler · December 20, 2004, 3:49pm

Will the default EDU code have stuff that i can just upload and make it work, just to learn the workings?

Mark_McLeod · December 20, 2004, 3:55pm

Yes. Start with that. Also get the EDU documentation from the innovationfirst.com website:
http://innovationfirst.com/FIRSTRobotics/pdfs/EDU-RC-2004_Ref_Guide_2004-Jan-14a.pdf
http://innovationfirst.com/FIRSTRobotics/pdfs/EDU_Default_Software_Guide_10-15-2003.pdf
http://innovationfirst.com/FIRSTRobotics/pdfs/EDU_Default_02-16-04.zip

doyler · December 20, 2004, 4:01pm

And I just use MPLAB IDE to mess with it right?

Also, what kind of code am i looking for just to make these things move for starters

What code(s) will I have to upload as well?

Mark_McLeod · December 20, 2004, 4:17pm

Yes, learn to use MPLAB.
How about putting something like this where it says “/* Add your own code here. */” in the file “user_routines.c” in the routine “[size=2]Process_Data_From_Master_uP”
[/size]


static unsigned char servo1=0; //Put these two lines right before the "Getdata" call
static unsigned char counter=0; // ditto
 
//Put these lines after "Add your own code"
 
if (counter < 20) // about half a second in the slow loop
counter++;
else
{
counter = 0;
 
if (servo1 < 255)
	servo1++; // servo1 will slowly step through each of it’s positions
else
	servo1 = 0; // servo1 will quickly reset to the zero position
}
pwm03 = servo1;

doyler · December 20, 2004, 4:21pm

Thank you, i will fiddle and learn from that code (is user routines akin to autonomous cause i dont know how im gonna make them move if it isnt)

1 more question (i hope) how and what do i upload to my controller now?

Mark_McLeod · December 20, 2004, 4:35pm

Here are the basic steps:

You’ll need to install MPLAB, IFI_Loader, and the mcc18 compiler on your computer.
Download the default EDU code from http://innovationfirst.com/FIRSTRobotics/documentation.htm (this will have a default.hex file that can be downloaded into the controller without having to edit anything with MPLAB) Save the original .zip file so you can restore the default code if some edit goes terribly wrong.

To edit the default code:

Start MPLAB
Select File -> Open Workspace…
Browse to the EDU default code folder
Open Default.mcw
Make your code changes
Use the “Build All” icon or select Project -> Build All (this will create a .hex file)

Start IFI_Loader

Browse to the default code folder
Select “Default.hex”
Connect the serial cable from your computer to the EDU controller
Turn on the EDU controller
Press the “Prog” button until the program light turns orange
Click on “Download” in IFI_Loader

Your program will start running.

doyler · December 20, 2004, 4:39pm

C:…\EDU_Default_02-16-04\user_routines.c:249:Error: syntax error
Halting build on first failure as requested.
BUILD FAILED: Mon Dec 20 16:36:48 2004

here is the snippet i edited


/*******************************************************************************
* FUNCTION NAME: Process_Data_From_Master_uP
* PURPOSE:       Executes every 17ms when it gets new data from the master 
*                microprocessor.
* CALLED FROM:   main.c
* ARGUMENTS:     none
* RETURNS:       void
*******************************************************************************/
void Process_Data_From_Master_uP(void)
{
  Getdata(&rxdata);   /* Get fresh data from the master microprocessor. */

  Default_Routine();  /* Optional.  See below. */

  /* Add your own code here. */

  static char servo1=0;
  static char counter=0;
 
  if (counter < 20) // about half a second in the slow loop
    counter++;
  else
  {
     counter = 0;
     if (servo1 < 254)
	   servo1++; // servo1 will slowly step through each of it’s positions
     else
  	   servo1 = 0; // servo1 will quickly reset to the zero position
  }
  pwm03 = servo1;

  printf("PWM OUT 7 = %d, PWM OUT 8 = %d
",(int)pwm07,(int)pwm08);  /* printf EXAMPLE */

  Putdata(&txdata);             /* DO NOT CHANGE! */
}

(sorry if i am being annoying, im just new at this)

Mark_McLeod · December 20, 2004, 4:43pm

Variable declarations must be at the very beginning of a routine. I noted that above in an edit after my original post. Sorry about that.

doyler:


/*******************************************************************************
* FUNCTION NAME: Process_Data_From_Master_uP
* PURPOSE: Executes every 17ms when it gets new data from the master 
* microprocessor.
* CALLED FROM: main.c
* ARGUMENTS: none
* RETURNS: void
*******************************************************************************/
void Process_Data_From_Master_uP(void)
{
static unsigned char servo1=0;
static unsigned char counter=0;
Getdata(&rxdata); /* Get fresh data from the master microprocessor. */
 
Default_Routine(); /* Optional. See below. */
 
/* Add your own code here. */
 
if (counter < 20) // about one 1/3 second in the slow loop
counter++;
else
{
counter = 0;
if (servo1 < 255)
	 servo1++; // servo1 will slowly step through each of it’s positions
else
	 servo1 = 0; // servo1 will quickly reset to the zero position
}
pwm03 = servo1;
 
printf("PWM OUT 7 = %d, PWM OUT 8 = %d
",(int)pwm07,(int)pwm08); /* printf EXAMPLE */
 
Putdata(&txdata); /* DO NOT CHANGE! */
}

(sorry if i am being annoying, im just new at this)

You’re not annoying. I like to help you get started.

doyler · December 20, 2004, 4:54pm

Error - Source file ‘C:…\ifi_utilities.c’ name exceeds file format maximum of 62 characters.

silly mplab

[edit]

hmm, do i need to install my usb to serial converter?

[/edit]

Mark_McLeod · December 20, 2004, 4:55pm

Have that default code folder sitting on your desktop don’t you?:rolleyes:

doyler · December 20, 2004, 4:56pm

yeah, but i have a keyspan usb -> serial

does xp not auto add it?

[edit]

Build Succeeded!

now to add it to the controler

[/edit]

Mark_McLeod · December 20, 2004, 5:02pm

XP will. [edit2] But you probably have to install that particular device driver the first time. An install CD should have come with the converter, or you might be able to download the driver from keyspan.

Are you getting a download error using IFI_Loader?
Sometimes those adaptors auto connect to a different COM port than it advertises. You can run through and try all the possible COM ports in IFI_Loader by choosing “PortSettings” and COM1, try to download, then COM2, and try to download, etc.

[edit]
I misunderstood.
Do you have the controller or will you try that later?

For those of you reading along…
The error doyler got was because one of the path and filenames was too long for MPLAB to handle. Combined they cannot be more than 62 characters or so. The usual solution is to keep the directory for all your FIRST code at the top level of the C drive, i.e., “C:\FIRST” not on your desktop because that’s really at “C:\Documents and Settings\doyler\Desktop” which is already 41 characters long.