?? main.c
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/* ----------------------------------------------------------------------------
* ATMEL Microcontroller Software Support
* ----------------------------------------------------------------------------
* Copyright (c) 2008, Atmel Corporation
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the disclaimer below.
*
* Atmel's name may not be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
* DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* ----------------------------------------------------------------------------
*/
//------------------------------------------------------------------------------
// Headers
//------------------------------------------------------------------------------
#include <board.h>
#include <pio/pio.h>
#include <pio/pio_it.h>
#include <pit/pit.h>
#include <aic/aic.h>
#include <tc/tc.h>
#include <utility/led.h>
#include <utility/trace.h>
//TODO
#include <rtc/rtc.h>
//TODO
#include <pwmc/pwmc.h>
#include <stdio.h>
//------------------------------------------------------------------------------
// Internal variables
//------------------------------------------------------------------------------
/// Delay for pushbutton debouncing (in milliseconds).
#define DEBOUNCE_TIME 500
/// PIT period value in 祍econds.
#define PIT_PERIOD 1000
// TODO A2-Step 1.1
/// List of button pins that must be configured for use by the application.
static const Pin pPins[] = {PINS_DBGU, PIN_PWMC_PWM1};
static const Pin pinPB1 = PIN_PUSHBUTTON_1;
static const Pin pinPB2 = PIN_PUSHBUTTON_2;
/// Indicates the current state (on or off) for each LED.
static unsigned char pLedStates[2] = {1, 1};
/// Global timestamp in milliseconds since start of application.
volatile unsigned int timestamp = 0;
//------------------------------------------------------------------------------
// Local functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// Handler for PIT interrupt. Increments the timestamp counter.
//------------------------------------------------------------------------------
static void ISR_Pit(void)
{
unsigned int status;
// Read the PIT status register
status = PIT_GetStatus() & AT91C_PITC_PITS;
if (status != 0) {
// Read the PIVR to acknowledge interrupt and get number of ticks
timestamp += (PIT_GetPIVR() >> 20);
}
}
//------------------------------------------------------------------------------
/// Configure the periodic interval timer to generate an interrupt every
/// millisecond.
//------------------------------------------------------------------------------
static void ConfigurePit(void)
{
// Initialize the PIT to the desired frequency
PIT_Init(PIT_PERIOD, BOARD_MCK / 1000000);
// Configure interrupt on PIT
AIC_DisableIT(AT91C_ID_SYS);
AIC_ConfigureIT(AT91C_ID_SYS, AT91C_AIC_PRIOR_LOWEST, ISR_Pit);
AIC_EnableIT(AT91C_ID_SYS);
PIT_EnableIT();
// Enable the pit
PIT_Enable();
}
//------------------------------------------------------------------------------
/// Interrupt handler for pushbutton #1. Starts or stops LED#1.
//------------------------------------------------------------------------------
static void ISR_Bp1(void)
{
static unsigned int lastPress = 0;
// Check if the button has been pressed
if (!PIO_Get(&pinPB1)) {
// Simple debounce method: limit push frequency to 1/DEBOUNCE_TIME
// (i.e. at least DEBOUNCE_TIME ms between each push)
if ((timestamp - lastPress) > DEBOUNCE_TIME) {
lastPress = timestamp;
// Toggle LED state
pLedStates[0] = !pLedStates[0];
if (!pLedStates[0]) {
LED_Clear(0);
}
}
}
}
//------------------------------------------------------------------------------
/// Interrupt handler for pushbutton #2. Starts or stops LED#2 and TC0.
//------------------------------------------------------------------------------
static void ISR_Bp2(void)
{
static unsigned int lastPress = 0;
// Check if the button has been pressed
if (!PIO_Get(&pinPB2)) {
// Simple debounce method: limit push frequency to 1/DEBOUNCE_TIME
// (i.e. at least DEBOUNCE_TIME ms between each push)
if ((timestamp - lastPress) > DEBOUNCE_TIME) {
lastPress = timestamp;
// Disable LED#2 and TC0 if there were enabled
if (pLedStates[1]) {
pLedStates[1] = 0;
LED_Clear(1);
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
}
// Enable LED#2 and TC0 if there were disabled
else {
pLedStates[1] = 1;
LED_Set(1);
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
}
}
}
}
//------------------------------------------------------------------------------
/// Configure the pushbuttons to generate interrupts.
//------------------------------------------------------------------------------
static void ConfigureButtons(void)
{
#if defined(at91sam7lek) || defined(at91cap9dk)
const Pin pinCol0 = PIN_KEYBOARD_COL0;
PIO_Configure(&pinCol0, 1);
#endif
// Configure pios
PIO_Configure(&pinPB1, 1);
PIO_Configure(&pinPB2, 1);
// Initialize interrupts
PIO_InitializeInterrupts(AT91C_AIC_PRIOR_LOWEST);
PIO_ConfigureIt(&pinPB1, (void (*)(const Pin *)) ISR_Bp1);
PIO_ConfigureIt(&pinPB2, (void (*)(const Pin *)) ISR_Bp2);
PIO_EnableIt(&pinPB1);
PIO_EnableIt(&pinPB2);
}
//------------------------------------------------------------------------------
/// Configure LEDs #1 and #2 (cleared by default).
//------------------------------------------------------------------------------
static void ConfigureLeds(void)
{
LED_Configure(0);
LED_Configure(1);
}
//------------------------------------------------------------------------------
/// Interrupt handler for TC0 interrupt. Toggles the state of LED #2
//------------------------------------------------------------------------------
static void ISR_Tc0(void)
{
// Clear status bit to acknowledge interrupt
AT91C_BASE_TC0->TC_SR;
// Toggle LED state
LED_Toggle(1);
}
//------------------------------------------------------------------------------
/// Configure Timer Counter 0 to generate an interrupt every 250ms.
//------------------------------------------------------------------------------
static void ConfigureTc(void)
{
unsigned int div;
unsigned int tcclks;
// Enable peripheral clock
AT91C_BASE_PMC->PMC_PCER = 1 << AT91C_ID_TC0;
// Configure TC for a 4Hz frequency and trigger on RC compare
TC_FindMckDivisor(4, BOARD_MCK, &div, &tcclks);
TC_Configure(AT91C_BASE_TC0, tcclks | AT91C_TC_CPCTRG);
AT91C_BASE_TC0->TC_RC = (BOARD_MCK / div) / 4; // timerFreq / desiredFreq
// Configure and enable interrupt on RC compare
AIC_ConfigureIT(AT91C_ID_TC0, AT91C_AIC_PRIOR_LOWEST, ISR_Tc0);
AT91C_BASE_TC0->TC_IER = AT91C_TC_CPCS;
AIC_EnableIT(AT91C_ID_TC0);
// Start the counter if LED is enabled.
if (pLedStates[1]) {
TC_Start(AT91C_BASE_TC0);
}
}
//------------------------------------------------------------------------------
/// Waits for the given number of milliseconds (using the timestamp generated
/// by the PIT).
/// \param delay Delay to wait for, in milliseconds.
//------------------------------------------------------------------------------
static void Wait(unsigned long delay)
{
volatile unsigned int start = timestamp;
unsigned int elapsed;
do {
elapsed = timestamp;
elapsed -= start;
}
while (elapsed < delay);
}
//------------------------------------------------------------------------------
// Exported functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// Main function
//------------------------------------------------------------------------------
int main()
{
//TODO
unsigned int DutyCycle;
//TODO
unsigned char hour, minute, second;
PIO_Configure(pPins, PIO_LISTSIZE(pPins));
DBGU_Configure(DBGU_STANDARD, 115200, BOARD_MCK);
printf("-- Getting Started Project 1.4 --\n\r");
printf("Board : %s, Chip ID : 0x%08X\n\r", BOARD_NAME, AT91C_BASE_DBGU->DBGU_CIDR);
// Configuration
ConfigurePit();
ConfigureTc();
ConfigureButtons();
ConfigureLeds();
// TODO A2-Step 1.2
// Enable PWMC peripheral clock
AT91C_BASE_PMC->PMC_PCER = 1 << AT91C_ID_PWMC;
// TODO A2-Step 1.3
// Set clock A to run at 30000Hz (clock B is not used)
PWMC_ConfigureClocks(30000, 0, BOARD_MCK);
// Configure PWMC channel #1
PWMC_ConfigureChannel(1, AT91C_PWMC_CPRE_MCKA, 0, 0);
// Period is CLK divided by the Period
PWMC_SetPeriod(1, 10);
// Duty cycle of 10% - Period/ Duty cycle value
PWMC_SetDutyCycle(1, 1);
// TODO A2-Step 2.1
// Duty cycle of 100% - Period/ Duty cycle value
//PWMC_SetDutyCycle(1, 10);
// TODO A2-Step 1.4
// Enable channel #1
PWMC_EnableChannel(1);
// TODO A3-Step 1.1
// Set time
RTC_SetTime(10, 0, 0);
// Main loop
while (1) {
// TODO A2-Step 3.1 Optional
//DutyCycle = (DutyCycle+1)%10;
// Wait for LED to be active
while (!pLedStates[0]);
// TODO A3-Step 1.2
// Get time
RTC_GetTime(&hour, &minute, &second);
// Display Time
printf("Time: %02d:%02d:%02d\r", hour, minute, second);
// Toggle LED state if active
if (pLedStates[0]) {
LED_Toggle(0);
}
//TODO A2-Step 1.6 Optional
//PWMC_SetDutyCycle(1, DutyCycle);
// Wait for 500ms
//Wait(500);
//TODO A3-Step 2.1 Optional
//Wait for the next second
while ( (AT91C_BASE_RTC->RTC_SR & AT91C_RTC_SECEV) != AT91C_RTC_SECEV);
AT91C_BASE_RTC->RTC_SCCR = AT91C_RTC_SECEV;
}
}
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