Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

I'm wondering if there is a trick to using FIRST Forge that would allow us to download all the source code for WPILib C++ 4.3 in one fell swoop, rather than downloading each of the C++ source files one at a time from the WPILib C++ home at FIRST Forge. I'm not very familiar with FIRST Forge, so I'm wondering if there is a link or command that will download the latest versions of every source file all at once.

We were able to download all the source code for WPILib C++ v4.0 on the WPILib C++ FRC Updates web page. But we are hoping to grab the latest and greatest source code, corresponding to WPILib C++ v4.3, if possible.

If there's no trick, we'll download each file individually, no problem. I just wanted to check. Many thanks!

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

Yes. Download svn from http://subversion.apache.org/packages.html. Once you've installed svn checkout the source from http://firstforge.wpi.edu/svn/repos/wpilibcpp

If you downloaded tigris version of svn (command-line) you can use :

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

You can also grab the source snapshot of update 4.1. Updates 4.2 and 4.3 don't have different code, just the compiled binary is different (due to build tool problems).

-Joe

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

If you want to be tricky, you can always download the update executable and use 7-zip or an equivalent program to extract the files inside. :D

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

But that will only get you the header files, not the C++ files.

-Joe

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

BTW, do you have the link to the 4.1 source code? I only find 4.0 source code in the following link:
http://first.wpi.edu/FRC/frccupdates.html

In particular, I am interested in the source code for the ADXL345_I2C code because I want to find out if it does calibration at initialization just like the gyro does. We played with the accelerometer and noticed that the axes values are non-zero when the robot is perfectly still. It wouldn't be too much a problem until we decided to integrate the acceleration for velocity and again for distance. With a non-zero accerleration at rest, the distance will slowly drifted up (or down). It is not too hard to write calibration code at initialization to find the "zero point equivalent" but I just want to make sure the original code does not have this already.

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

http://firstforge.wpi.edu/sf/frs/do/...4_1_2 0100205

The included class does not calibrate the accelerometer because most teams using them as a tilt sensor would not want gravity calibrated out since it would cause strange behavior when it does tilt.

-Joe

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

Tilt is from the Z-axis, right? So I could calibrate the X and Y axes and still get tilt. Another issue with the accelerometer is noise. We would like the calibration process to auto determine the deadband range during initialization. Is there any down side of doing that?
Thanks.

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

Any data you throw away (deadband) is lost accuracy when integrating. Typically you should prefer averaging over deadbanding. If your system has too much noise (which has been my experience) then integration simply won't work very well... especially double integration... especially for any length of time.

-Joe

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

Actually, after thinking about it, I know what you mean now. When the robot is tilted, both the X and Y axes will have some G on it even if it is still.

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

Exactly.

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

Hmm, shouldn't integration smooth out noise? Noise is supposed to be superimposing on the actual value (i.e. it will be above at one point and below at another). So both averaging and integration should cancel out noise in the long run, shouldn't it?

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

Yes, integration (and averaging... accumulation is averaging without the divide) smooths out noise. Deadbanding does not, though... what you should prefer to do if you are getting drift is to improve the calibration for your 0G offset. You could possibly implement a dynamic 0G point based on other sensor data, such as all wheels are stopped so set the 0G point to the current value.

-Joe

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

That's what I am thinking, doing a 0G calibration. But why do I need to do 0G calibration dynamically? Shouldn't it be enough doing it once at the beginning? I imagine it may be necessary if I am on a slope but then 0G will change if you change heading, so 0G calibration is useless on a slope anyway. But if I only care about level ground, doing 0G calibration at the beginning should be enough unless 0G point will change with time (or with temperature like the gyro). Even if it does change with time or temperature, the one-time calibration should be good enough for the duration of the competition.

Re: Is there an easy way to download all the source code for WPILib C++ v4.3 at once?
 

Your mileage may vary. I have found there to be too much non-uniform noise for double integration to work well enough to be usable. It will very much depend on what you want to be able to do with it.

Best of luck!
-Joe