Hello again everyone,
Sorry for bumping my own post, however...
Thanks to inspiration I got from Diego Zviovich post on Sous-vide
http://community.wolfram.com/groups/-/m/t/170725, it seems only natural to make a MathLink program to control the PiFace.
So, since it is snowing outside, and I have a cup of coffee in my hand, I have taken the liberty to write some code which, at least for my own basic needs, does the trick.
Initially I downloaded and installed the C-library by Thomas Macpherson, at
https://github.com/thomasmacpherson/piface. I here assume that you have succesfully installed your own PiFace and can test it with the accompanying emulator.
Firstly, I wrote the code in C, required for the MathLink. I wrote:
#include "mathlink.h"
#include "libpiface-1.0/pfio.h"
int initializePFIO(void)
{
return pfio_init();
}
int deinitializePFIO(void)
{
return pfio_deinit();
}
int leds(int led, int onOff)
{
pfio_digital_write(led,onOff);
return 0;
}
int switches(int pin)
{
return pfio_digital_read(pin);
}
int relays(int relay, int onOff)
{
pfio_digital_write(relay,onOff);
return 0;
}
int main(int argc, char* argv[])
{
return MLMain(argc,argv);
}
:Begin:
:Function: leds
:Pattern: Leds[led_Integer, onOff_Integer]
:Arguments: { led, onOff }
:ArgumentTypes: { Integer, Integer }
:ReturnType: Integer
:End:
:Evaluate: Leds::usage = "Leds[led_Integer, onOff_Integer] turns on/off (1/0) led x on PiFace."
:Begin:
:Function: initializePFIO
:Pattern: InitializePFIO[]
:Arguments: Manual
:ArgumentTypes: Manual
:ReturnType: Integer
:End:
:Evaluate: Initialize::usage = "Initialize[] initialize PiFace I/O."
:Begin:
:Function: deinitializePFIO
:Pattern: DeinitializePFIO[]
:Arguments: Manual
:ArgumentTypes: Manual
:ReturnType: Integer
:End:
:Evaluate: Initialize::usage = "Deinitialize[] deinitialize PiFace I/O."
:Begin:
:Function: relays
:Pattern: Relays[relay_Integer, onOff_Integer]
:Arguments: { relay , onOff }
:ArgumentTypes: { Integer , Integer}
:ReturnType: Integer
:End:
:Evaluate: Initialize::usage = "Relays[relay_Integer , onOff_Integer] turns on/off (1/0), relay 0 or 1 on the PiFace I/O."
:Begin:
:Function: switches
:Pattern: Switches[pin_Integer]
:Arguments: { pin }
:ArgumentTypes: { Integer }
:ReturnType: Integer
:End:
:Evaluate: Initialize::usage = "Switches[pin_Integer] reads the state of input pin x on the PiFace I/O."
I wrap this up using the mcc command, and linking the libpiface-1.0 library appropriately. Note: Dont forget that these are the paths I used, yours might be different.
./mcc -L/usr/local/lib -lpiface-1.0 -o piface_mathematica.exe piface_mathematica.tm piface_mathematica.c
This creates the required executable, which can be made available to Mathematica:
Install["/home/pi/Desktop/CProgramming/piface_mathematica.exe"]
Now it is possible to control, relays, switches and LEDS (shoudl be able to communicate with input/output pins also). As an example, the following code turns on and off the PiFace LEDS in ascending and descending sequence at 1 second intervals.
(*Initialize PiFace Digital IO*)
InitializePFIO[]
(*Execute the LED light sequence*)
For[i = 0, i < 8, i++, Leds[i, 1]; Pause[1];
If[i == 7, For[i = 7, i > -1, i--, Leds[i, 0]; Pause[1];] ]]
(*Turn off all LEDS*)
Leds[#, 0] & /@ Range[0, 7]
(*Close the link*)
DeinitializePFIO[]
Hope someone can use it. Please let me know if you have suggestions/corrections to the code.
Best Regards
Simon
