/******************************************************************************
*	This demo application illustrates how to use the VXI Word Serial Char Driver
*	and an M-Module ANSI-C driver to control an M-Module instrument on C&H's 
*	VX406C Intelligent M-Module Carrier.  The VXI Word Serial Char Driver is part 
*	of C&H's Embedded Linux Distribution for the intelligent carriers.
*
*	This particular example was written for the VX406C however the concept carriers
*	over to all of C&H's VXI Intelligent Carrier (VX406C, VX407C, VX411C).
*
*	The application should be compiled and linked to run on the MPC8245 resident 
*	on the carrier.  The recommended toolchain is ELDK available from www.denx.de.
*
*	This demo uses the M395 DAC M-Module.  The demo will open the VXI Word Serial 
*	Char Driver using Non-Blocking I/O (Blocking I/O is also available) and wait 
*	for a word serial message from the VXI host.  When a message is received it 
*	perform the function of the command.
*
*	Commands can be cutomized to be any sequence of ASCII characters up top 256
*	bytes.  The commands implemented in this demo are as follows:
*
*	volt <dac_value>  -   Set the DAC output voltage to the value specified
*	sweep             -   Causes the DAC to sweep from 0 to 5 votls with a 1ms 
*	                      delay at each volatge.  An VXI interrupt is generated
*	                      when the sweeping is done.
*	volt?             -   Return the current DAC output value
*	clearirq          -   Clears the pending VXI interrupt.
*
*
*******************************************************************************/

#include <stdio.h>
#include "apis.h"
#include "m395defs.h" 
#include <fcntl.h>
#include <string.h>


int main (void)
{	APIS_HANDLE m395;
	int i;
	int fd;
	char command[256], string[256];
	int value;
	int current_value;

	printf("M395 Demo Program\n\n");

	fd = open("//dev//VXI", O_RDWR | O_NONBLOCK);         //We could also perform Blocking I/O

	m395_open (0, &m395);                                 //Open and init the driver
	m395_boot (m395);                                     //M395 must be booted
	
	m395_select_range (m395, V10UNI);                     //Set range to +10V unipolar
	m395_select_upd_mode(m395, CONT);                     //Set update mode to continuous
	
	while(1)
	{	if(read(fd, command, 1) == 1)                       //Read a command from the VXI bus
		{	if(strncmp(command, "volt ", 5) == 0)
			{	sscanf(command, "volt %x", &value);
				m395_setchan(m395, 0, value);
				current_value = value;
			}	
			else if(strncmp(command, "sweep", 5) == 0)
			{	for(i=0; i<0x800; i++)
				{	apis_delay(1);
					m395_setchan(m395, 0, i);
					current_value = i;
				}
				chvx406clinux_GenerateVxiInterrupt(m395, 0xAA);  //Send VXI interrupt when done sweeping
			}
			else if(strncmp(command, "volt?", 5) == 0)
			{	sprintf(string, "0x%x", current_value);
				write(fd, string, strlen(string));               //Send the result to VXI bus
			}
			else if(strncmp(command, "clearirq", 8) == 0)
				chvx406clinux_ClearVxiInterrupt(m395);
		}
		
	}


	m395_close (m395);
	return 0;	
}