160 lines
4.7 KiB
C
160 lines
4.7 KiB
C
#include "LPC17xx.h"
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// PWM variables
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unsigned long int duty_cycle = 0;
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unsigned long int pwm_counter = 0;
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// Pin definitions
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#define LED_SHIFT 4 // CNA: P0.4-P0.11
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#define LED_MASK (0xFF << LED_SHIFT)
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// Keypad on CND - ROW-0
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#define COL0 (1<<0) // P2.0
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#define COL1 (1<<1) // P2.1
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#define COL2 (1<<23) // P0.23
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#define COL3 (1<<24) // P0.24
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#define ROW0 (1<<25) // P0.25
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#define COL_MASK_P0 (COL2 | COL3)
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#define COL_MASK_P2 (COL0 | COL1)
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#define PWM_PERIOD 100 // Smaller for faster PWM
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static void short_delay(volatile unsigned int d) {
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while(d--) __NOP();
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}
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static void set_column(unsigned int col)
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{
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LPC_GPIO2->FIOSET = COL_MASK_P2;
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LPC_GPIO0->FIOSET = COL_MASK_P0;
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switch(col) {
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case 0: LPC_GPIO2->FIOCLR = COL0; break;
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case 1: LPC_GPIO2->FIOCLR = COL1; break;
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case 2: LPC_GPIO0->FIOCLR = COL2; break;
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case 3: LPC_GPIO0->FIOCLR = COL3; break;
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}
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}
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static unsigned int is_row0_pressed(void)
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{
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return !(LPC_GPIO0->FIOPIN & ROW0);
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}
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// PWM Interrupt Handler - Software PWM
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void PWM1_IRQHandler(void)
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{
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if (LPC_PWM1->IR & (1 << 0))
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{
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// Software PWM for all 8 LEDs
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if(pwm_counter < duty_cycle)
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LPC_GPIO0->FIOSET = LED_MASK; // All LEDs ON
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else
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LPC_GPIO0->FIOCLR = LED_MASK; // All LEDs OFF
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pwm_counter++;
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if(pwm_counter >= PWM_PERIOD)
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pwm_counter = 0;
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LPC_PWM1->IR = (1 << 0); // Clear interrupt
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}
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}
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int main(void)
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{
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unsigned int col_idx;
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unsigned int candidate_key = 0xFF;
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unsigned int stable = 0;
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unsigned int last_key = 0xFF;
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// === SYSTEM CLOCK SETUP (Optional but recommended) ===
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SystemInit(); // Use default clock setup
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// === PIN CONFIGURATION ===
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LPC_PINCON->PINSEL0 &= ~(0xFFFF << 8); // Clear P0.4-P0.11 (GPIO)
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LPC_PINCON->PINSEL1 &= ~(0xFFFF << 14); // Clear P0.23-P0.28
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LPC_PINCON->PINSEL3 &= ~(0x3 << 14); // Clear P1.23
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LPC_PINCON->PINSEL4 &= ~(0xF << 0); // Clear P2.0-P2.1
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// === GPIO DIRECTION SETUP ===
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LPC_GPIO0->FIODIR |= LED_MASK; // P0.4-P0.11: LEDs (output)
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LPC_GPIO0->FIODIR |= COL_MASK_P0; // Keypad columns (output)
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LPC_GPIO2->FIODIR |= COL_MASK_P2; // Keypad columns (output)
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LPC_GPIO0->FIODIR &= ~ROW0; // Row-0 (input)
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// === INITIALIZE GPIO ===
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LPC_GPIO0->FIOCLR = LED_MASK; // All LEDs off initially
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LPC_GPIO2->FIOSET = COL_MASK_P2; // Columns high
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LPC_GPIO0->FIOSET = COL_MASK_P0; // Columns high
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// === PWM CONFIGURATION ===
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LPC_SC->PCONP |= (1 << 6); // Power on PWM1
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LPC_PWM1->TCR = (1 << 1); // Reset PWM
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LPC_PWM1->CTCR = 0; // Timer mode
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LPC_PWM1->PR = 99; // Prescaler: divide by 100
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// Creates ~10kHz interrupt rate
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LPC_PWM1->MR0 = PWM_PERIOD; // PWM period = 100
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LPC_PWM1->MR4 = 0; // Duty cycle = 0
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LPC_PWM1->MCR = (1 << 1) | (1 << 0); // Reset on MR0, interrupt enabled
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LPC_PWM1->LER = (1 << 0); // Latch MR0
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NVIC_EnableIRQ(PWM1_IRQn); // Enable PWM interrupt
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NVIC_SetPriority(PWM1_IRQn, 0); // Highest priority
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LPC_PWM1->TCR = (1 << 0) | (1 << 3); // Enable PWM and counter
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// Initial duty cycle: 10%
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duty_cycle = 10;
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// === MAIN LOOP ===
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while(1)
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{
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unsigned int read_key = 0xFF;
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// Scan ROW-0 (keys 0, 1, 2, 3)
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for(col_idx = 0; col_idx < 4; col_idx++)
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{
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set_column(col_idx);
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short_delay(500);
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if(is_row0_pressed()) {
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read_key = col_idx;
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break;
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}
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}
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// Restore columns
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LPC_GPIO2->FIOSET = COL_MASK_P2;
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LPC_GPIO0->FIOSET = COL_MASK_P0;
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// Debounce
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if(read_key == candidate_key) {
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if(stable < 5) stable++;
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} else {
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candidate_key = read_key;
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stable = 1;
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}
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// Update intensity when stable
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if(stable >= 5) {
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if(candidate_key != last_key && candidate_key != 0xFF) {
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last_key = candidate_key;
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// Set duty cycle (out of 100)
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switch(candidate_key) {
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case 0: duty_cycle = 10; break; // 10%
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case 1: duty_cycle = 25; break; // 25%
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case 2: duty_cycle = 50; break; // 50%
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case 3: duty_cycle = 75; break; // 75%
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}
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}
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stable = 5;
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}
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short_delay(5000);
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}
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}
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