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1  Using Arduino / Interfacing w/ Software on the Computer / Re: Transmitting large integers over serial to Arduino on: March 04, 2012, 04:53:33 pm
Thanks!

I figured out a different way: I send the integer as a string, then convert it using atoi();
2  Using Arduino / Interfacing w/ Software on the Computer / Re: Transmitting large integers over serial to Arduino on: March 04, 2012, 04:26:43 pm
Oh, no. I want to send 1000 bit values TO the arduino. I have no problems having the arduino send large values to java. I just send them as strings and convert.

It's an issue because I want to send degree values to servos, so if I want to say, send 179 to a servo, I have problems.
3  Using Arduino / Interfacing w/ Software on the Computer / Transmitting large integers over serial to Arduino on: March 04, 2012, 04:15:02 pm
Hi,

I currently have a working java program using rxtx.

I'm trying to send the arduino large numbers, say, like 1000. However any number >127 comes back as something else.

if I send it 128, I get random numbers. Sometimes 194, 195, 208.

What's going on? How do I send it larger numbers? I know there's got to be an easy solution to this..I haven't worked with C for a while.
4  Topics / Robotics / Re: Non-Odometric Navigation? on: March 01, 2012, 02:19:47 pm
Hah, I figured as much... I took a course on AI back in college. Understanding, then IMPLEMENTING complex algorithms takes a long time, never mind various optimizations, trouble shooting, blah blah blah. Took me a week of working a few hours a day just to get a SAT solver running.

I was hoping there was some kind of SLAM library out there, you know like how there are libraries for quicksort in Java or C++ and the like..sigh.

I'll do a separate post asking about SLAM resources and the like.
5  Topics / Robotics / Re: Robot Platform using a Netbook on: February 29, 2012, 10:30:56 am
You can use Java and the rxtx library to interface with serial if you're worried about platform dependent languages.
6  Topics / Robotics / Non-Odometric Navigation? on: February 29, 2012, 10:26:58 am
Hi,

I've looked at several methods of navigation like SLAM and WAVEFRONT and well, they're extremely complex. It seems to me that a lot of the concrete implementations involve odometry. However odometry is generally unreliable.

Is there a way to calculate distance moved based on original positioning without utilizing odometry?

I've seen some stuff using a Kinect to recognize glyphs and such, but that's a little expensive for me. That, and it relies on sticking glyphs/beacons everywhere. I'd prefer a non-beacon based navigation/mapping

I've had some thoughts about utilizing sonar 'topography' IE, defining a region by sweeping around a PING sensor around on a servo. Since I have a heading given by a compass unit, I can assign that 'sweep' to an array. If I move forward, say 10 cm which I determine with the PING sensor, I take another sweep. If I turn, I know via my compass heading..and so on and so forth.

I feel like I'm on to something, but I don't quite know what. Maybe mapping/navigation based on wall following??
7  Topics / Science and Measurement / Re: Calculating heading distance, and direction on: February 28, 2012, 12:51:19 am
Thanks for the help!

But it doesn't quite work.

Check out this example
Init Heading: 5
Target Heading: 355

num1=355-5=350
num2=5-360=-355-355=-710

350 is selected as our distance

350+5= 355, so we go clockwise.

When infact, to get to 355 from 5, we should be going counterclockwise 10 degrees.

Any ideas?
8  Topics / Science and Measurement / Calculating heading distance, and direction on: February 27, 2012, 09:10:51 pm
Hi,

I'm having an extremely difficult time getting heading calculations correctly.

For example:
I have a rover with a current heading of 270 degrees
I want it to face 100 degrees.
How do I calculate
-What is the shortest distance, in degrees, to get to 100?
-Which direction should the rover turn to get to 100?

I know it should be very simple, but for some reason the math is really throwing me off.

9  Using Arduino / Motors, Mechanics, and Power / Re: Arduino Motor Shield V3 acting weird on: February 13, 2012, 10:20:01 am
Yep, that's the one. I guess I'll try setting the pinMode(number,OUTPUT); for each break pin, see if that works. And I guess I'll set pinMode(number,INPUT) for the two current sensors.

It's odd, I didn't have these kinds of problems with the Adafruit motorshield at all, but they do supply a handy library for it. Do you know if there is an Arduino Motor Shield library available??

Are there any other threads/guides to using this particular motor shield? when I do a search most people refer to AF or other brands of motor shields.
10  Using Arduino / Motors, Mechanics, and Power / Re: Arduino Motor Shield V3 acting weird on: February 13, 2012, 02:42:30 am
OKay, I went ahead and did that. The result is that they activate more reliably, but the results are still spotty. Every 1 out of 3 tries I still have to 'spin' the wheel to get it going.
11  Using Arduino / Motors, Mechanics, and Power / Arduino Motor Shield V3 acting weird on: February 12, 2012, 07:25:41 pm
Hi,

SO I have the code below. Both wheels are supposed to turn forward. They start out turning forward, then one of the motor seems to 'suck up' the energy and turn forward at a faster speed. The other motor slows down and stops running. If I hold the running motor down, and force it 'back', then the other motor starts running.

What gives? I thought it might be an power issue, so I hooked up an additional 9.6 Lithium ion battery directly to the motor board. No change, except the motors run faster.

Also, the motors simply don't spin if I set pin 12 and 13 to 1. So turning left/right is impossible.

I purchased the components from radio shack. (Like, from a store front
-Arduino Uno Rev 3
-Arduino Motor Shield Rev 3
-2x Metal Gear 1.5-3V DC Motor
 

Code:
void setup()
{
 
}

void loop()
{
 
  digitalWrite(12,0);
  digitalWrite(13,0);
  analogWrite(11,233);
  analogWrite(3,233);
  delay(1000);
 
}


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