PIC32MX: Analog Inputs - Revision history

Andrew Long at 15:53, 12 April 2010

2010-04-12T15:53:17Z

NickMarchuk: /* Sample Code */

2010-03-03T23:59:49Z

Sample Code

NickMarchuk: /* Analog Inputs Example */

2010-03-03T23:40:02Z

Analog Inputs Example

NickMarchuk: /* Sample Code */

2010-03-02T21:36:41Z

Sample Code

Andrew Long: /* Sample Code */

2010-01-05T20:44:38Z

Sample Code

Show changes

Andrew Long: PIC32MX460F512L : Analog Inputs moved to PIC32MX: Analog Inputs

2009-08-13T15:33:32Z

PIC32MX460F512L : Analog Inputs moved to PIC32MX: Analog Inputs

Andrew Long: /* Available Pins */

2009-07-30T19:43:34Z

Available Pins

Andrew Long: /* Available Pins */

2009-07-30T19:43:22Z

Available Pins

Andrew Long: New page: Analog-to-Digital Conversion (ADC) is a useful capability of many PIC microcontrollers. This ADC produces a digital value based on the supplied analog voltage, which can then be used with ...

2009-07-30T19:41:42Z

New page: Analog-to-Digital Conversion (ADC) is a useful capability of many PIC microcontrollers. This ADC produces a digital value based on the supplied analog voltage, which can then be used with ...

New page

Analog-to-Digital Conversion (ADC) is a useful capability of many PIC microcontrollers. This ADC produces a digital value based on the supplied analog voltage, which can then be used with the digital logic of the rest of the PIC. The PIC32 converts analog inputs in the range 0-5V to digital values between 0 and 1023 (10-bit resolution).

==Available Pins==
<br><br>

==Analog Inputs Example==
This section uses an example to describe how to set up and read digital inputs using a PIC32MX460F512L.

===Sample Code===
Program to LED output on the UBW32 board based on analog input of 2 POTs.

First include header files with definitions for generic type definitions, compiler, and for specific PIC. Also include the plib header file.

#include "GenericTypeDefs.h"
#include "Compiler.h"
#include "HardwareProfile.h"
#include <plib.h>

NOTE THAT BECAUSE WE USE THE BOOTLOADER, NO CONFIGURATION IS NECESSARY. THE BOOTLOADER PROJECT ACTUALLY CONTROLS ALL OF OUR CONFIG BITS.

Define the system frequency
#define SYS_FREQ (80000000L)

Define global variables for analog results
unsigned short int channel4; // conversion result as read from result buffer
unsigned short int channel5; // conversion result as read from result buffer

Begin main function
int main(void)
{

Configure the proper PB frequency and the number of wait states
SYSTEMConfigPerformance(SYS_FREQ);

configure and enable the ADC
CloseADC10(); // ensure the ADC is off before setting the configuration

Define setup parameters for OpenADC10 (the parameter options are located in adc10.h located in the include peripheral folder) Below is an example:

// Turn module on | output in integer | trigger mode auto | enable autosample
#define PARAM1 ADC_MODULE_ON | ADC_FORMAT_INTG | ADC_CLK_AUTO | ADC_AUTO_SAMPLING_ON

// ADC ref external | disable offset test | enable scan mode | perform 2 samples | use one buffer | use MUXA mode
#define PARAM2 ADC_VREF_AVDD_AVSS | ADC_OFFSET_CAL_DISABLE | ADC_SCAN_ON | ADC_SAMPLES_PER_INT_2 | ADC_ALT_BUF_OFF | ADC_ALT_INPUT_OFF

// use ADC internal clock | set sample time
#define PARAM3 ADC_CONV_CLK_INTERNAL_RC | ADC_SAMPLE_TIME_15

// set AN4 and AN5
#define PARAM4 ENABLE_AN4_ANA | ENABLE_AN5_ANA

// do not assign channels to scan
#define PARAM5 SKIP_SCAN_AN0 | SKIP_SCAN_AN1 | SKIP_SCAN_AN2 | SKIP_SCAN_AN3 | SKIP_SCAN_AN6 | SKIP_SCAN_AN7 | SKIP_SCAN_AN8 | SKIP_SCAN_AN9 | SKIP_SCAN_AN10 | SKIP_SCAN_AN11 | SKIP_SCAN_AN12 | SKIP_SCAN_AN13 | SKIP_SCAN_AN14 | SKIP_SCAN_AN15

// use ground as neg ref for A
SetChanADC10( ADC_CH0_NEG_SAMPLEA_NVREF); // configure to sample AN4

configure ADC using parameter define above
OpenADC10( PARAM1, PARAM2, PARAM3, PARAM4, PARAM5 );

Enable the ADC
EnableADC10();

wait for the first conversion to complete so there will be valid data in ADC result registers
while ( ! mAD1GetIntFlag() ) { }

Initialize all of the LED pins on the UBW32
mInitAllLEDs();

main loop
while (1)
{

Read the result of channel 4 (the first channel to be read) and turn on / off the LED
channel4 = ReadADC10(0);
if (channel4 > 511)
{
mLED_3_On();
}
else
{
mLED_3_Off();
}

Read the result of channel 5 (the first channel to be read) and turn on / off the LED
channel5 = ReadADC10(1);
if (channel5 > 511)
{
mLED_4_On();
}
else
{
mLED_4_Off();
}

end the main function
return 0;
}

← Older revision		Revision as of 15:53, 12 April 2010
Line 1:		Line 1:
	Analog-to-Digital Conversion (ADC) is a useful capability of many PIC microcontrollers. This ADC produces a digital value based on the supplied analog voltage, which can then be used with the digital logic of the rest of the PIC. The PIC32 converts analog inputs in the range 0-5V to digital values between 0 and 1023 (10-bit resolution).		Analog-to-Digital Conversion (ADC) is a useful capability of many PIC microcontrollers. This ADC produces a digital value based on the supplied analog voltage, which can then be used with the digital logic of the rest of the PIC. The PIC32 converts analog inputs in the range 0-3.3V to digital values between 0 and 1023 (10-bit resolution).

	==Available Pins==		==Available Pins==

@@ Line 37: / Line 37: @@
  	// define setup parameters for OpenADC10
  			    // ADC ref external    | disable offset test    | enable scan mode | perform 2 samples | use one buffer | use MUXA mode
+        // note: to read X number of pins you must set ADC_SAMPLES_PER_INT_X
  	#define PARAM2  ADC_VREF_AVDD_AVSS | ADC_OFFSET_CAL_DISABLE | ADC_SCAN_ON | ADC_SAMPLES_PER_INT_2 | ADC_ALT_BUF_OFF | ADC_ALT_INPUT_OFF

@@ Line 6: / Line 6: @@
 ==Analog Inputs Example==
-This section uses an example to describe how to set up and read digital inputs using a PIC32MX460F512L.
+This section uses an example to describe how to set up and read analog inputs using a PIC32MX460F512L.
 ===Sample Code===

@@ Line 51: / Line 51: @@
  	#define PARAM5	SKIP_SCAN_AN0 | SKIP_SCAN_AN1 | SKIP_SCAN_AN2 | SKIP_SCAN_AN3 | SKIP_SCAN_AN6 | SKIP_SCAN_AN7 | SKIP_SCAN_AN8 | SKIP_SCAN_AN9 | SKIP_SCAN_AN10 | SKIP_SCAN_AN11 | SKIP_SCAN_AN12 | SKIP_SCAN_AN13 | SKIP_SCAN_AN14 | SKIP_SCAN_AN15
- 	// use ground as neg ref for A | use AN4 (B4) for input A
+ 	// use ground as neg ref for A
+ 	SetChanADC10( ADC_CH0_NEG_SAMPLEA_NVREF); // use ground as the negative reference
- 	// configure to sample AN4
- 	SetChanADC10( ADC_CH0_NEG_SAMPLEA_NVREF); // configure to sample AN4
  	OpenADC10( PARAM1, PARAM2, PARAM3, PARAM4, PARAM5 ); // configure ADC using parameter define above

← Older revision	Revision as of 15:33, 13 August 2009
(No difference)

@@ Line 3: / Line 3: @@
 ==Available Pins==
 The PIC32MX460F512L has 16 available analog pins denoted ANX on the pin list, where x is from 0 to 15.
 <br><br>