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1  Products / Arduino Due / Re: Implementing FFT on the DUE on: March 11, 2013, 08:00:08 am
Here is an FFT library that works at high level so should be OK on the Due. I use it on the Mega. Send him an email with a brief description of your project and he will send you the library in a reply.

http://www.arduinoos.com/2010/10/fast-fourier-transform-fft/
2  Products / Arduino Due / Re: Using the Hardware Quadrature Encoder Channel on the DUE on: February 20, 2013, 07:16:47 pm
Use one of the same buffer chips but connect Vss to 5V. As long as your input signal crosses around the 50% point, the output will switch states. Use the B version of the chip as it's switching level is better defined. Check the data sheet on AllDataSheet.com.

http://pdf1.alldatasheet.com/datasheet-pdf/view/26876/TI/CD4050B.html


3  Products / Arduino Due / Re: Using the Hardware Quadrature Encoder Channel on the DUE on: February 20, 2013, 03:48:35 pm
A hex buffer, CD4050, will work nicely. Power the Vss pin with 3V3 to establish the output level. The inputs will take 5V signals.

4  Products / Arduino Due / Re: IDE 1.5.2 released! on: February 10, 2013, 10:43:02 am
The verbose output for the Uno upload is not being honored. The IDE and the preferences.txt file are set correctly. However, it is working in the Due.
5  Products / Arduino Due / Re: The 5v/3.3v issue on: January 28, 2013, 04:46:24 pm
As long as the signal is not bi-directional, you can use a CD4050 hex buffer chip. Use a supply voltage to power the chip equal to the output voltage max you need.
6  Products / Arduino Due / Re: Octave/Matlab Vector Programming in Due on: January 28, 2013, 02:14:04 pm
This may help.

Code:
int freeRam() {
  extern int __heap_start, *__brkval;
  int v;
  return (int) &v - (__brkval == 0 ? (int) &__heap_start : (int) __brkval);
}
7  Products / Arduino Due / Re: Problem installing Due driver on: January 23, 2013, 08:18:08 am
Aim it only at the Driver folder. Windows will find the appropriate sub-folder.
8  Products / Arduino Due / Re: New UTFT Libray with Arduino ARM spport on: January 22, 2013, 06:23:58 pm
I found a copy here in RAR format.

http://henningkarlsen.com/electronics/download.php?f=UTFT.rar


9  Products / Arduino Due / Re: Why do I get servo jitter when disconnected from USB? on: January 22, 2013, 09:12:41 am
The servo current draw is probably low enough to not exceed the USB limit but too much for the Due on-board regulator. You'll need a separate regulator for the 5V servo.
10  Products / Arduino Due / Re: Running Dynamixel on Arduino Due on: January 20, 2013, 06:00:12 pm
I am using the Mega to control two MX-64T servos. I see no reason why it cannot be used on the Due in the same fashion.

Here is how it's done. First, the AX-12 library didn't work. You can still #include it to get the #defines. However, I just copied the #define block and changed the compliance constants to the PID values in the correct registers. Next, copy the AX routines for register read8, write8, and write16 to appropriately name functions in your sketch. Once you have these written, you can create other functions by just writing to the appropriate registers. You won't need that many.

On the hardware side, the Mega serial1 port is used with the baud set to 57,600, the servos default. You can go much higher but I had no need to do so, therefore, have no idea where the upper limit lies. The servos have a specific set of baud values set by a series of constants. The match is not perfect but within the tolerance of RS232.

There was also a strange problem in the wiring of the half-duplex line. Fortunately, it can be fixed with a single 1K resistor. I found that I could talk to the servos but not receive any data back. The problem is that the sender in the servo cannot overcome the pullup effect of the Mega TX1 line. This can be solved with a 1K resistor between the Mega TX1 and RX1 pins. The 1K is then in series with the TX1 line going out but the input impedance of the servo receiver is high so no net effect. On receive, the 1K resistor is a pullup which the servo can overcome.

My application is a stable platform for aerial photography so I need only two servos, roll and pitch. The tilt signal comes from an ADXL345 accelerometer breakout board on I2C. The two servos are daisy chained and fed through a single cable. I like the Dynamixel servos due to their high torque, absolute position sensing, high angular resolution, and digital communication.
11  Products / Arduino Due / Re: Project targeting AVR and Due on: January 20, 2013, 12:56:53 pm
I tried a similar scheme. It didn't solve my particular problem but the approach works.

#if defined(__SAM3X8E__)
    #include <sam/SomeDueThing.h> // For the Due
#else
    #include <avr/SomeAVRThing.h>    // For anything else
#endif
12  Products / Arduino Due / Re: Arduino due and dtostrf function problem on: January 14, 2013, 03:32:04 pm
You might try to find the library containing the function and put it in the #include section. I've tried it with other functions using the complete path and it still doesn't see it. Even the math.h file is not found. There appears to be a serious path problem with this version of the IDE. Not sure what your function does but sprintf() may work in it's place. It worked nicely for my application.
13  Products / Arduino Due / Re: Tombstones on Due on: January 08, 2013, 07:42:19 am
Trace length is important only at very high frequencies. The Due is not in that category. Serpentine traces are used to help anchor the copper to the board. Line straight lines tend to lift if they experience a temperature change. Think of it as expansion joints.
14  Products / Arduino Due / Re: Library Problem With IDE V1.5.1r2 And Due on: January 06, 2013, 09:10:34 am
Moving the Wire library from the sketch folder to some other place, eliminates the avr/io.h error. The sketch still compiles when selecting the Mega. However, now I get another error about a missing item, square. Including math.h does not solve the problem. There is still a path problem when selecting the Due.

C:\Users\xxxxx\Documents\Arduino\libraries\PlainFFT\PlainFFT.cpp:143: error: 'square' was not declared in this scope
15  Products / Arduino Due / Re: Library Problem With IDE V1.5.1r2 And Due on: January 06, 2013, 07:26:27 am
If I eliminate the one in {sketchbook_folder}\libraries, will the compiler find the right one in sam or avr according to board selection. Will this damage my ability to use V1.0.3 for other boards.
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