Analog-to-Digital Converter (ADC/ADC12B) example for SAM.

#include <string.h>
#include "asf.h"
#include "conf_board.h"

Macros
#define	ADC_DONE_MASK ( (1<<NUM_CHANNELS) - 1 )
	There are two peripherals ADC and ADC12B in SAM3U, you can select one of them. More...

#define	BUFFER_SIZE NUM_CHANNELS
	Size of the receive buffer and transmit buffer. More...

#define	MENU_HEADER

#define	STRING_EOL "\r"
	ADC channel for potentiometer. More...

#define	STRING_HEADER

#define	VOLT_REF (3300)
	Reference voltage for ADC, in mv. More...

Enumerations
enum	{ TRIGGER_MODE_SOFTWARE = 0, TRIGGER_MODE_ADTRG, TRIGGER_MODE_TIMER }
	ADC trigger modes. More...

Functions
static void	configure_console (void)
	Configure UART console. More...

static void	configure_time_trigger (void)
	Configure to trigger ADC by TIOA output of timer. More...

static void	display_menu (void)
	Display ADC configuration menu. More...

int	main (void)
	adc12 Application entry point. More...

static void	mdelay (uint32_t ul_dly_ticks)
	Wait for the given number of milliseconds (using the dwTimeStamp generated by the SAM microcontrollers' system tick). More...

static void	set_adc_test_mode (void)
	Set ADC test mode. More...

static void	start_adc (void)
	Read converted data through PDC channel. More...

void	SysTick_Handler (void)
	Systick handler. More...

Variables
enum { ... }	e_trigger_mode
	ADC trigger modes. More...

struct {
uint8_t uc_ch_num [NUM_CHANNELS]

uint16_t us_done

uint16_t us_value [NUM_CHANNELS]

}	g_adc_sample_data
	ADC sample data. More...

struct {
uint8_t uc_gain_en

uint8_t uc_offset_en

uint8_t uc_pdc_en

uint8_t uc_sequence_en

uint8_t uc_trigger_mode

}	g_adc_test_mode
	ADC test mode structure. More...

static volatile uint32_t	gs_ul_ms_ticks = 0
	Global timestamp in milliseconds since start of application. More...

#define ADC_DONE_MASK ( (1<<NUM_CHANNELS) - 1 )

There are two peripherals ADC and ADC12B in SAM3U, you can select one of them.

Total number of ADC channels in use ADC convention done mask.

Referenced by main().

#define BUFFER_SIZE NUM_CHANNELS

Size of the receive buffer and transmit buffer.

Referenced by start_adc().

#define MENU_HEADER

Value:

"\n\r" \
        "===================================================\n\r" \
        "Menu: press a key to change the configuration.\n\r" \
        "---------------------------------------------------------\n\r"

Referenced by display_menu().

#define STRING_EOL "\r"

ADC channel for potentiometer.

#define STRING_HEADER

Value:

"-- ADC 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 main().

anonymous enum

ADC trigger modes.

Enumerator
TRIGGER_MODE_SOFTWARE
TRIGGER_MODE_ADTRG
TRIGGER_MODE_TIMER

static void configure_console ( void )

static

Configure UART console.

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_time_trigger ( void )

static

Configure to trigger ADC by TIOA output of timer.

References ADC_TRIG_TIO_CH_0, gpio_configure_pin, pmc_enable_periph_clk(), sysclk_get_cpu_hz(), tc_find_mck_divisor(), tc_init(), and tc_start().

Referenced by start_adc().

static void display_menu ( void )

static

Display ADC configuration menu.

References g_adc_test_mode, MENU_HEADER, TRIGGER_MODE_ADTRG, TRIGGER_MODE_SOFTWARE, and TRIGGER_MODE_TIMER.

Referenced by main(), and set_adc_test_mode().

int main ( void )

adc12 Application entry point.

Returns: Unused (ANSI-C compatibility).

References adc_disable_interrupt(), ADC_DONE_MASK, adc_start(), board_init(), configure_console(), display_menu(), g_adc_sample_data, g_adc_test_mode, MAX_DIGITAL, mdelay(), pwm_channel_disable(), set_adc_test_mode(), start_adc(), STRING_HEADER, sysclk_get_cpu_hz(), sysclk_init(), tc_start(), TRIGGER_MODE_SOFTWARE, uart_read(), us_value, and VOLT_REF.

static void mdelay ( uint32_t ul_dly_ticks )

static

Wait for the given number of milliseconds (using the dwTimeStamp generated by the SAM microcontrollers' system tick).

Parameters

ul_dly_ticks Delay to wait for, in milliseconds.

References gs_ul_ms_ticks.

Referenced by main().

static void set_adc_test_mode ( void )

static

Set ADC test mode.

References display_menu(), g_adc_test_mode, TRIGGER_MODE_ADTRG, TRIGGER_MODE_SOFTWARE, TRIGGER_MODE_TIMER, and uart_read().

Referenced by main().

static void start_adc ( void )

static

Read converted data through PDC channel.

Parameters

p_adc	The pointer of adc peripheral.
p_s_buffer	The destination buffer.
ul_size	The size of the buffer. Start ADC sample. Initialize ADC, set clock and timing, and set ADC to given mode.

References ADC_CHANNEL_POTENTIOMETER, adc_enable_channel(), adc_enable_interrupt(), ADC_GAINVALUE_0, ADC_GAINVALUE_2, adc_get_status(), adc_read_buffer(), ADC_TRIG_EXT, ADC_TRIG_SW, BUFFER_SIZE, configure_time_trigger(), g_adc_sample_data, g_adc_test_mode, gpio_configure_pin, pmc_enable_periph_clk(), sysclk_get_cpu_hz(), TRIGGER_MODE_ADTRG, TRIGGER_MODE_SOFTWARE, and TRIGGER_MODE_TIMER.