A New Programmer

[Spartan151]

Hi. I'm Sean, current leader of team 2065. We have no real programming abilities as of yet. However, after printing off a guide I found here, I have a somewhat decent understanding of how to write it....I think.
I wrote a test code based off of what was on the 12-page manual, and I would like someone who has some programming experience to take a look at it and comment on it. I need to know what I'm doing right and wrong.
The program I have written is a code for autonomous mode. The actions encompass the following:

drive forward for 3 seconds
turn left for half a second
drive foward for one and a half seconds
turn left again for half a second
drive forward for three seconds
turn left for half a second
drive forward for one second
stop until the remaining time is up.

Please, comments are greatly appreciated.

Note: I deliberately left it as a .txt file for easy access.

[Laaba 80]

Looks pretty good for the first time. One thing though, once you find out it works, you will want to make it go faster, because right now it is going a little under half speed, and I'm assuming this is code to race around the track, so you will want to go fast. Nice job, if you have other questions, let me know.
Joey

[Spartan151]

Thank you. I chose small numbers because I just wanted to do a test, and I do intend to increase those numbers once I'm sure that I did it right. I know I'll have to do some checking on the right motor, because for some reason it seems a little laggier than the left motor on our robot.
There'll be a bunch of fine tuning involved, but from your standpoint, what would be a good number for some good speeds? We'll be going for every possible option that we can.
There'll be a lot of testing come Tuesday (That's when our materials for the tower and arm come in) to see whether or not it works.

Okay. Here's a question. Our team's computer both has EasyCPro and the Compiler, but how exactly do I go extracting the default, editing the code, and putting it back in the RC?

[Laaba 80]

Im not sure with Easy C, I use MP Lab. I'll tell you how its done in MP Lab, and hopefully you can figure Easy C out. In the Kit, you got some serial cables. plug the red cable into the robot controller and the operator interface with the joysticks. It says TEATHER where you put that in. Take the black cable and plug into the robot controller. I cant remember what the port says, but I'm guessing it says something like PROGRAM. If you are using a newer laptop you may run into some problems connecting to the computer because they dont have serial ports any more, let me know if that is your case. When everything is turned on press and hold the PROG button on the robot controller until some lights turn yellow. Open up the compiler, open up the hex file that you just built and download into the robot. Hopefully that helped. If there is any thing else let me know and I'll do my best to help.
Joey

[Spartan151]

Thanks very much. I'll keep you updated as to how it progresses.

So, I can use MPLab to extract the default code and edit it, correct?

[Laaba 80]

Ok, Good Luck
Joey

[RyanCahoon]

Originally Posted by Spartan151

So, I can use MPLab to extract the default code and edit it, correct?

You'll need to get the default code from the IFI website here.

- Once you've extracted all the files, open the FrcCode.mcw file. It should load MPLAB.
- You should see two windows, the Project Browser and the Output window. In the Project Browser, double click on user_routines_fast.c
- Scroll down to the User_Autonomous_Code function. Insert the autonomous code you written after the line that reads

/* Add your own autonomous code here. */

- Follow the directions here on how to download your code to your robot.

Good luck
--Ryan

P.S.: Remember to check your semicolons!

[paulcd2000]

Originally Posted by Spartan151

I know I'll have to do some checking on the right motor, because for some reason it seems a little laggier than the left motor on our robot.

THat's usually the case. It happens (to us anyway) because the motor on the right wheel is turned around. The motors don't run the same speeds forwards an backwards, so when the left is running full fwd and the right full bwd, they're in the same direction, but the speeds are off slightly. It doesn't change a lot if ur moving slowly, since the system has a lot of friction, but when you gear up the speeds, the robot doesn't go anywhere near straight (speaking from personal experience in a narrow hallway)

[Alan Anderson]

Originally Posted by paulcd2000

It happens (to us anyway) because the motor on the right wheel is turned around. The motors don't run the same speeds forwards an backwards, so when the left is running full fwd and the right full bwd, they're in the same direction, but the speeds are off slightly.

The CIM motors don't have significant bias. They'll run the same speed in both directions. If you're reversing the motor direction for the other side of the robot by swapping the wires, the speeds should match well.

However, the Victor speed controllers do appear to have an asymmetric response around the defined neutral value of 127. If you're accounting for the need to reverse the motor direction in code, you'll probably notice this. When we tested things last year, true neutral seemed to be closer to 132.

[marccenter]

Looking at your code, I would recommend that you replace some of your absolute numbers with Calibration
values for future ease of Use. That way,you can change one Calibration value at the top of your program and it
changes all the values in your program saving you valuable editing time and the possibility of an editing bo-bo. For Example, if Fwd is > 127 for pwm outputs, try something Like Fwd_Low = 150 ; Fwd_Med = 170 ;Fwd_High = 190 , Similiarly, if
Rwd is < 127 how about Rev_Low = 104, Rev_Med = 84, and Rev_High = 64.

[Spartan151]

Thanks for all the help guys. You've all been great. I'll be testing those things ASAP. Now, there are some other things I need help with, also. Our robot's claw is run by pneumatics. On our arm control, I need to program two buttons on the joystick (Or one to do both functions) to open and close the claw. How would I go about porgramming the buttons?

[Spartan151]

Originally Posted by marccenter

Looking at your code, I would recommend that you replace some of your absolute numbers with Calibration
values for future ease of Use. That way,you can change one Calibration value at the top of your program and it
changes all the values in your program saving you valuable editing time and the possibility of an editing bo-bo. For Example, if Fwd is > 127 for pwm outputs, try something Like Fwd_Low = 150 ; Fwd_Med = 170 ;Fwd_High = 190 , Similiarly, if
Rwd is < 127 how about Rev_Low = 104, Rev_Med = 84, and Rev_High = 64.

Could you explain exactly what you mean? I'm having difficulty understanding, partly because the computer I'm using now doesn't have MPLAB and partly because I only understand autonomous programming to a degree.

[blaxbb]

under ///*** DEFINE USER VARIABLES AND INITIALIZE THEM HERE ***/ or at the top of any .c file

to make it easier you should define your speeds so that you can update all of your speed values without changing every single one.

you can define your speeds once and call them multiple times

#define stop 127
#define forward 200
#define reverse 50

then instead of saying

pwm01 = 200;
pwm02 = 50;

you can say

pwm01 = forward;
pwm02 = reverse;

this makes it so much easier if you need to change a value quickly (at a competition)

[Spartan151]

Okay. It's beginning to make sense now. I'll give it a shot.

[Spartan151]

Okay. Once I get the basics done, I will need help programming the IR board functions, and programming the pneumatics for our claw to the arm joystick. I'll let you know when we get to that stage, but please, feel free to explain ahead of time. It'll help our team get a better understanding so there's no head-scratching later.