led.rar_LED_avr led

/*----------------------------------------------------------------------------- * File: LED01.C * Author: David Boydston - Solutions Consulting - http://www.serialio.com * Copyright (c) 1999 Solutions Consulting All Rights Reserved. * * Function: Test the light sequence on Atmel 8515 development board * Lights should blink one at a time 'up' from PB0 to PB7 then back 'down' * from PB7 to PB0. Then the lights will 'stack up' from PB0 to PB7 and * 'stack down' from PB7 to PB0. At any time when the PB2 button is * pressed the lights should display with an alternating pattern momentarily * then continue with the blinking pattern. * * See disclaimer at http://www.serialio.com/Legal/SoftDisclaimer.htm *---------------------------------------------------------------------------*/ #include <io8515.h> #include <macros.h> #define CLK_DIV_BY_0 0x01 //rolls at 8.19ms with 4Mhz Clock #define CLK_DIV_BY_8 0x02 //rolls at 65.5ms with 4Mhz Clock #define CLK_DIV_BY_64 0x03 //rolls at 524ms with 4Mhz Clock #define CLK_DIV_BY_256 0x04 //rolls at 2.1sec with 4Mhz Clock #define CLK_DIV_BY_1024 0x05 //rolls at 8.4sec with 4Mhz Clock #define TMR1_OVF_INT_ENA 0x80 #define GLOBAL_INT_ENA 0x80 #define INT0_ENA 0x40 #define INT0_TRIG_FALL_EDGE 0x02 #define INT1_ENA 0x80 unsigned char tmrRollFlag = 0; void delay2(unsigned char); #pragma interrupt_handler ISR_int0_handler:2 //Note: GIMSK I-bit cleared by MCU on INT and set by MCU on RETI //Thus there should be no danger of us being involked multiple //times by switch bounce (as long as delay is reasonable to see LED) void ISR_int0_handler() { unsigned char a, b; PORTB = 0x55; delay2(5); //doing this in ISR causes heavy stack use. /* //this way is easier on the stack for (a = 1; a; a++) for (b = 1; b; b++) ; */ } #pragma interrupt_handler ISR_tmr1_ovf_handler:7 void ISR_tmr1_ovf_handler() { // PORTB = 0x0f; //sanity check tmrRollFlag = 1; } void delay(unsigned char n) { int i; for (i = 0; i < n; i++) { tmrRollFlag = 0; while (!tmrRollFlag); //wait for IRQ } } #ifdef FIXED_DELAY void delay() { tmrRollFlag = 0; while (!tmrRollFlag); //wait for IRQ } #endif void delay2(unsigned char n) { unsigned char a, b, c; for (a = 1; a; a++) for (b = 1; b; b++) for (c = 1; c<n; c++) ; } void LED_On(int i) { PORTB = ~BIT(i); /* low output to turn LED on */ // delay2(0); delay(3); } void main() { signed char i, v; DDRB = 0xFF; /* output */ PORTB = 0x55; //sanity check delay2(5); TCCR1A = 0; TCCR1B = CLK_DIV_BY_8; // TCCR1B = CLK_DIV_BY_64; TIMSK = TMR1_OVF_INT_ENA; MCUCR = INT0_TRIG_FALL_EDGE; MCUCR = 0; //low level trig GIMSK = INT0_ENA; SREG = GLOBAL_INT_ENA; //enable ints while (1) { /* forward march */ for (i = 0; i < 8; i++) LED_On(i); /* backward march, don't repeat bit 7 */ for (i = 6; i >= 0; i--) LED_On(i); //PORTB = 0xF0; //sanity check //delay(); /* stack, don't repeat bit 0 */ for (i = 0, v = 3; i < 7; i++) { PORTB = ~v; v |= v << 1; delay(3); } /* unstack */ for (i = 0, v = 0x7F; i < 8; i++) { PORTB = ~v; v &= v >> 1; delay(3); } } }