adc_compact/main.c

===== Description =====

This demo shows how to use the ADC (Analog to Digital) converter on SBC66 Netcruzer boards. The SBC66 Netcruzer boards have 12 Analog input ports, port 0-5 and 30-35 (old port names X0-X5, and Y0-Y5). For details see modtronix.com/product/sbc66ec/ For this demo, ports 2 and 5 (X2 and X5) are configured as Analog Inputs. By default the ADC is configured for voltages between 0 - 2.5V (To configure it for 3.3V inputs, see nz_analog.h file). This demo turns pins 38 and 39 (Y8 and Y9) on or off depending on the ADC values read on 2 and 5 (X2 and X5) pins. This demo is configured to create compact code, by adding the following 3 lines to the projdefs.h file:

#define ADC_NO_MV_FUNCTIONS        //No millivolt functions included
#define ADC_NO_CONVERT_FUNCTIONS   //No convert functions included
#define ADC_NO_CHAN_FUNCTIONS      //Don't support any channel functions - use indexed functions

This removes lots of code from the nz_analog module. Only indexed functions accessing ADC's 10-bit value can now be used. No channel (adcReadChan for example) or millivolt functions (adcReadChanMv for example) are available.

The following line is also added to the projdefs.h file, and dramatically reduces the RAM used by the nz_analog module. It indicates that we only use 2 ADC inputs, and space for all possible ones (12) does not have to be reserved.

#define ADC_MAX_CHAN   2

===== Required Hardware =====

This project can be run on any of our SBC66 Netcruzer boards. For prototyping, we recommend combining this board with a Prototyping Board, like the PT66ECI for example. This low cost prototyping board makes all the I/O ports of the SBC66 board available via marked labels on the PCB. It also provides a reset and firmware button that simplifies prototyping.

===== Building Project =====

This project is located in the "src/demos/adc/adc_compact" folder of the Netcruzer Download. To compile for Netcruzer Board, open this project in MPLAB X, and select the "Project Configuration" for desired board. For example "SBC66ECL_R2" for the SBC66ECL Revision 2 board. For details click here

===== Programming Board =====

After compiling (build), the board can be programmed via the USB Bootloader or a PIC Programmer. USB Programming is simplified when using the SBC board together with a Prototype Board.

===== File History =====

2012-08-08, David H. (DH):

• Initial version

#define THIS_IS_MAIN_FILE   //Uniquely identifies this as the file with the main application entry function main()

#include "HardwareProfile.h"    //Required for all Netcruzer projects

//For this demo, A2 (X2) is first channel (index 0), and A5 (X5) second channel (index 1)
#define ADC_INDEX_A2 0
#define ADC_INDEX_A5 1

int main(void)
{
    WORD tmrFlashLed = 0;  //Timer for flashing system LED

    nzSysInitDefault();             //Default initialization. All ports inputs. All analog features disabled. Tick 1ms

    DIR_SYSLED = OUTPUT_PIN;    //Set System LED port as outputs
    DIR_38 =     OUTPUT_PIN;    //Set Port 38 (old port name Y8) as an output pin
    DIR_39 =     OUTPUT_PIN;    //Set Port 39 (old port name Y9) as an output pin

    //Configure port 2 and 5 (old port names X2 and X5) as ADC channels
    adcOpen(ADC_OPEN_A2 | ADC_OPEN_A5);

    while(1)
    {
        nzSysTaskDefault();     //Main netcruzer task, call in main loop.

        //If analog input 2 (old port name X2) is above 2.0V (2000mV), set port 38 (old port name Y8) pin to 3.3V, else to 0V.
        // This funcion uses CONVERT_MV_TO_10BIT_ADC_VALUE() macro to get ADC 10-bit value for given millivolts.
        if (adcReadChanForIndex(ADC_INDEX_A2) > CONVERT_MV_TO_10BIT_ADC_VALUE(2000))
            PIN_38 = 1;
        else
            PIN_38 = 0;

        //If port 5 (old port name X5) analog input value is above 900 (0-2.5V = 0-1023), set port 39 (old port name Y9)
        //to 3.3V, else to 0V. This function gets te ADC's 10-bit value, which has a range from 0 - 1023.
        if (adcReadChanForIndex(ADC_INDEX_A5) > 900)
            PIN_39 = 1;
        else
            PIN_39 = 0;

        //Flash system LED every 500ms
        if (tick16TestTmr(tmrFlashLed)) {
            tick16UpdateTmrMS(tmrFlashLed, 500);     //Update timer to expire in 500ms again
            LAT_SYSLED = !LAT_SYSLED;       //Toggle System LED
        }
    }//end while

    return 0;
}//end main