/***************************************************************************** * SAMPLE4.C : DAC OUTPUT * * * * This is a demonstration program to be used with the AD12-16 A/D * * board. The program will prompt the user for a voltage between 0 and 5V. * * The program will output this value on DAC channel 0 and then read it back* * on ADC channel 0. This demos setting the scan limits(task 1), performing * * data conversion(task 3)and outputting to a DAC(task 15). * * This program must be built using the large model. * * * * The board should be set as follows: * * -- IRQ5 is used for interrupts * * -- Polarity set to bipolar * * -- DMA channel 1 * * -- On board clock set to 1 MHz * * * * The following jumpers should be isntalled: * * -- Pin 37, ADC channel 0 input -- to pin 9, DAC output channel 0. * * -- Pin 8, -5V reference -- to pin 10 DAC #0 reference in. * * * * LAST MODIFICATION: 2/3/98 * * * *****************************************************************************/ #include #include #include #include #include #include "a16drvc.h" /* These variable MUST be declared as global. They are the ones whose offsets are passed to the A16DRV routine. If they are not global then the driver will not find their segment. */ unsigned pntbuf[100],statcode,task; int datbuf[100],params[5]; unsigned AskForBaseAddress(unsigned int OldOne) { char msg[7]; int NewOne = 0, Success = 0, Dummy; int AddrInputPosX, AddrInputPosY; puts("\nPlease enter the Base Address for your card (in hex)"); printf("or press ENTER for %X.\n>", OldOne); AddrInputPosX = wherex(); AddrInputPosY = wherey(); do { gotoxy(AddrInputPosX, AddrInputPosY); clreol(); msg[0] = 5; msg[1] = 0; cgets(msg); sscanf(msg + 2, "%x", &NewOne); Success = 1; Dummy = NewOne; if (msg[1] == 0) { gotoxy(AddrInputPosX, AddrInputPosY); printf("%X", OldOne); Success = 1; Dummy = OldOne; } } while(!Success); return (Dummy); } /* end of AskForBaseAddress */ /***************************************************************************** * FUNCTION: call_driver -- local routine * * * * PURPOSE: Performs the call to the driver package. * * * * INPUT: None. * * * * CALLS: A16DRV - entry point to driver package. * * * * OUTPUT: Returns the error code supplied by the driver routine. * * * *****************************************************************************/ unsigned call_driver() { unsigned *temp1,offtask,offparams,offstatcode; int *temp; /* this section extracts the offset of the parameters that we will pass to the assembly driver */ temp1 = &task; offtask = FP_OFF(temp1); /* offset of task number */ temp = params; offparams = FP_OFF(temp); /* offset of param list */ temp1 = &statcode; offstatcode = FP_OFF(temp1); /* offset of status code */ statcode = 0; a16drv(offtask,offparams,offstatcode); /* call the driver */ /* this section checks for an error code */ if (statcode > 0) { printf("A status error code of %i was detected.\n",statcode); printf("Program terminated."); return(statcode); } else return(0); } /* end call_driver */ /***************************************************************************** * FUNCTION: setup -- local routine * * * * PURPOSE: Sets up the driver package to read channel 0. * * * * INPUT: None. * * * * CALLS: call_driver - entry point to driver package. * * * * OUTPUT: Returns the error code supplied by the driver routine. * * * *****************************************************************************/ unsigned setup(Address) { unsigned I,status; /* initialize the board */ params[0] = Address; /* starting board address */ params[1] = 5; /* IRQ5 */ params[2] = 1; /* DMA channel 1 */ task = 0; status = call_driver(); /* call driver */ if (status > 0) return(status); /* if status > 0 then error */ /* set the scan limits for channel 0 to channel 15 */ task = 1; params[0] = 0; /* lower scan limit */ params[1] = 0; /* upper scan limit */ status = call_driver(); /* call the driver */ if (status > 0) return(status); return(status); } /* end setup */ /***************************************************************************** * FUNCTION: get_readings -- local routine * * * * PURPOSE: Reads the 16 A/D channels and displays them on the screen. * * * * INPUT: None. * * * * CALLS: call_driver - entry point to driver package. * * * * OUTPUT: Returns the error code supplied by the driver routine. * *****************************************************************************/ unsigned get_readings() { unsigned I,status; float volts; clrscr(); /* fetch a voltage to output from the console */ printf("Enter a voltage to output(0-5.0v):"); scanf("%f",&volts); volts /= 5; volts *= 4095; /* set DAC 0 to output this voltage */ task = 15; params[0] = 0; params[1] = (int) volts; status = call_driver(); if (status > 0) return(status); /* exit if error */ for (I = 0;I < 2000;I++); /* now take the conversion, on channel 0. */ task = 3; status = call_driver(); if (status > 0) return(status); /* exit if error */ /* now if OK compute and list the data to the screen */ volts = (float) params[0] / 2047 * 5; printf("\nThe value read back is: %5.3f\n",volts); return(0); } /* end get_readings */ /***************************************************************************** * FUNCTION: main -- local routine * * * * PURPOSE: Controls program flow, detects when user is ready to exit. * * * * INPUT: None. * * * * CALLS: setup - set up program and drivers. * * get_readings - read the A/D channels and display. * * * * OUTPUT: None. * *****************************************************************************/ void main() { unsigned int Address; unsigned status; char ch; clrscr(); printf( " SAMPLE4.C : DAC OUTPUT \n\n" " This is a demonstration program to be used with the AD12-16 A/D \n" " board. The program will prompt the user for a voltage between 0 and 5V. \n" " The program will output this value on DAC channel 0 and then read it back\n" " on ADC channel 0. This demos setting the scan limits(task 1), performing \n" " data conversion(task 3)and outputting to a DAC(task 15). \n" " \n"); Address=AskForBaseAddress(0x350); clrscr(); printf( " Board Configuration Requirements: \n\n" " -- Base address is %X hex \n" " -- IRQ5 is used for interrupts \n" " -- Polarity set to bipolar \n" " -- DMA channel 1 \n" " -- On board clock set to 1 MHz \n" " \n" " The following jumpers should be isntalled: \n" " -- Pin 37, ADC channel 0 input -- to pin 9, DAC output channel 0. \n" " -- Pin 8, -5V reference -- to pin 10 DAC #0 reference in. \n",Address); puts("\n All remaining jumper settings are irrelevant."); printf("\n\n\nPress any key to continue, or press E to exit the program"); ch=getch(); status = setup(Address); /* set up program and the driver */ if (status != 0) return; /* is status > 0 then board error */ while (ch != 'E' && ch != 'e') { status = get_readings(); if (status != 0) return; /* if status > 0 then error */ /* check for program exit */ printf("\nPress E to exit the program. Press any other key to rescan the data..."); while (!kbhit); /* wait for key press */ ch = getch(); /* read the char */ } clrscr(); } /* end main program */