adc_threshold_wakeup_example.c File Reference

ADC threshold wakeup example for SAM.

Copyright (c) 2011-2018 Microchip Technology Inc. and its subsidiaries.

#include "asf.h"
#include "stdio_serial.h"
#include "conf_board.h"

Macros
#define	BOARD_ADC_FREQ   (6000000)
	ADC channel for potentiometer. More...
#define	MENU_HEADER
#define	STRING_EOL   "\r"
	The maximal digital value. More...
#define	STRING_HEADER
#define	VOLT_REF   (3300)
	Reference voltage for ADC, in mv. More...

Functions
void	ADC_Handler (void)
static void	configure_console (void)
static void	configure_tc0 (void)
	Configure Timer Counter 0 (TC0) to generate an interrupt every second. More...
static void	display_info (void)
	Display current information,including voltage on potentiometer, thresholds and comparison mode. More...
static void	display_menu (void)
	Display main menu. More...
static void	enter_asleep (void)
	Enter sleep mode using WFI instruction. More...
static uint32_t	f_to_int (float x)
	Transform float data type to int. More...
static uint8_t	get_comparison_mode (void)
	Get comparison mode. More...
static int16_t	get_voltage (void)
	Get voltage from user input (range from 0 to 3300 mv). More...
int	main (void)
	Example entry point. More...

Variables
static uint16_t	gs_us_high_threshold = 0
	High threshold. More...
static uint16_t	gs_us_low_threshold = 0
	Low threshold. More...

#define BOARD_ADC_FREQ   (6000000)

ADC channel for potentiometer.

ADC clock

#define MENU_HEADER

Value:

"\n\r-- Menu Choices for this example--\n\r" \
        "-- 0: Display voltage on potentiometer.--\n\r" \
        "-- 1: Modify low threshold.--\n\r" \
        "-- 2: Modify high threshold.--\n\r" \
        "-- 3: Choose comparison mode.--\n\r" \
        "-- i: Display ADC information.--\n\r" \
        "-- m: Display this main menu.--\n\r" \
        "-- s: Enter sleep mode.--\n\r"

Referenced by display_menu().

#define STRING_EOL   "\r"

The maximal digital value.

#define STRING_HEADER

Value:

"-- ADC Threshold Wakeup Example --\r\n" \
        "-- "BOARD_NAME" --\r\n" \
        "-- Compiled: "__DATE__" "__TIME__" --"STRING_EOL

Referenced by main().

#define VOLT_REF   (3300)

Reference voltage for ADC, in mv.

Referenced by ADC_Handler(), display_info(), get_voltage(), and main().

void ADC_Handler

(

void

)

References ADC_CHANNEL_POTENTIOMETER, adc_disable_interrupt(), adc_get_channel_value(), adc_get_status(), gs_us_high_threshold, gs_us_low_threshold, MAX_DIGITAL, and VOLT_REF.

static void configure_console ( void  )

static

References uart_rs232_options::baudrate, CONF_UART, CONF_UART_BAUDRATE, CONF_UART_PARITY, stdio_serial_init(), and sysclk_enable_peripheral_clock().

Referenced by main().

static void configure_tc0 ( void  )

static

Configure Timer Counter 0 (TC0) to generate an interrupt every second.

This interrupt will be used to display the number of bytes received on the UART.

References pmc_enable_periph_clk(), and tc_init().

Referenced by main().

static void display_info ( void  )

static

Display current information,including voltage on potentiometer, thresholds and comparison mode.

References ADC_CHANNEL_POTENTIOMETER, adc_get_channel_value(), f_to_int(), gs_us_high_threshold, gs_us_low_threshold, MAX_DIGITAL, and VOLT_REF.

Referenced by main().

static void display_menu ( void  )

static

Display main menu.

References MENU_HEADER.

Referenced by main().

static void enter_asleep ( void  )

static

Enter sleep mode using WFI instruction.

Enable interrupt first and then disable it after wake up.

References adc_enable_interrupt(), and adc_get_status().

Referenced by main().

static uint32_t f_to_int ( float  x )

static

Transform float data type to int.

Referenced by display_info(), and main().

static uint8_t get_comparison_mode ( void  )

static

Get comparison mode.

References uart_read().

Referenced by main().

static int16_t get_voltage ( void  )

static

Get voltage from user input (range from 0 to 3300 mv).

References uart_read(), and VOLT_REF.

Referenced by main().

int main

(

void

)

Example entry point.

Initialize ADC to 12-bit, enable channel "ADC_CHANNEL_POTENTIOMETER", then enable hardware trigger with TIOA0 every second. Finally, start conversion.

Returns

Unused (ANSI-C compatibility).

References ADC_CHANNEL_POTENTIOMETER, adc_enable_channel(), adc_get_channel_value(), ADC_TRIG_TIO_CH_0, board_init(), configure_console(), configure_tc0(), display_info(), display_menu(), enter_asleep(), f_to_int(), get_comparison_mode(), get_voltage(), gs_us_high_threshold, gs_us_low_threshold, MAX_DIGITAL, pmc_enable_periph_clk(), STRING_HEADER, sysclk_get_cpu_hz(), sysclk_init(), tc_start(), uart_read(), and VOLT_REF.

uint16_t gs_us_high_threshold = 0

static

High threshold.

Referenced by ADC_Handler(), display_info(), and main().

uint16_t gs_us_low_threshold = 0

static

Low threshold.

Referenced by ADC_Handler(), display_info(), and main().