ATMEGA48天狗项目的乐趣-天狗分析声音和根据它的响度-C程序-原理图文件-转载自国外网 - 圣源电子制作

/* -----------------------------------------------------------------------
* Title: Tengu like face use 8x5 LED display
* Author: Alexander Weber alex@tinkerlog.com
* Date: 22.10.2007
* Hardware: ATmega48
* Software: WinAVR 20070525
*
*/
#include <inttypes.h>
#include <stdlib.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#define TRUE 1
#define FALSE 0
#define LED_BIT PD4
#define SCROLL_COUNT_MAX 125
#define MAX_FACES 6
#define MAX_SAMPLES 10
#define SCALE 18
#define DELTA 20
#define CHANNEL 5
static volatile uint8_t soft_prescaler = 0; // soft prescaler
static volatile uint8_t screen_mem[8]; // screen memory
static volatile uint8_t active_col; // active column on screen
static volatile uint8_t col_ptr = 0; // active column in message
static volatile uint8_t scroll_count = 0;
// clock
static volatile uint16_t ms_count = 0;
static volatile uint8_t seconds = 0;
static volatile uint8_t minutes = 0;
static volatile uint8_t hours = 0;
static volatile uint8_t loudness = 0;
static volatile uint8_t active_face = 0;
static volatile uint8_t faces[MAX_FACES][8] = {
// { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}, // empty
{
0x00, // -----
0x0A, // -x-x-
0x00, // -----
0x0E, // -xxx-
0x00, // -----
0x00, // -----
0x00, // -----
0x00 // -----
},
{
0x00, // -----
0x0A, // -x-x-
0x00, // -----
0x0E, // -xxx-
0x0E, // -xxx-
0x00, // -----
0x00, // -----
0x00 // -----
},
{
0x00, // -----
0x0A, // -x-x-
0x00, // -----
0x0E, // -xxx-
//0x1F, // xxxxx
0x11, // x---x
//0x1F, // xxxxx
0x0E, // -xxx-
0x00, // -----
0x00 // -----
},
{
0x00, // -----
0x0A, // -x-x-
0x00, // -----
0x0E, // -xxx-
//0x1F, // xxxxx
0x11, // x---x
0x11, // x---x
//0x1F, // xxxxx
0x0E, // -xxx-
0x00 // -----
},
{
0x00, // -----
0x0A, // -x-x-
0x00, // -----
0x0E, // -xxx-
//0x1F, // xxxxx
0x11, // x---x
0x11, // x---x
0x11, // x---x
//0x1F // xxxxx
0x0E, // -xxx-
},
{
0x00, // -----
0x1B, // xx-xx
0x00, // -----
0x0E, // -xxx-
//0x1F, // xxxxx
0x11, // x---x
0x11, // x---x
0x11, // x---x
//0x1F // xxxxx
0x0E, // -xxx-
}
};
// prototypes
void display_active_col(void);
void scroll_video(void);
void clock_tick(void);
/*
* SIGNAL TIMER0_OVF_vect
* Handles overflow interrupts of timer 0.
* With prescaler 8 it is called with 4882.8125Hz at 10MHz, so the clock is
* not exact.
* A column update every 4 ticks = 1220.7Hz.
* The complete display = 1220.7Hz / 8 columns = 152.6Hz
*/
SIGNAL(TIMER0_OVF_vect) {
if ((ms_count % 4) == 0) {
display_active_col();
}
// count ms
if (++ms_count == 4882) {
clock_tick();
ms_count = 0;
}
}
/*
* get_adc
* Return the 10bit value of the selected adc channel.
*/
uint16_t get_adc(void) {
// ADC setup
ADCSRA =
(1 << ADEN) | // enable ADC
(1 << ADPS1) | (1 << ADPS0); // set prescaler to 8
// select channel
ADMUX = CHANNEL;
// warm up the ADC, discard the first conversion
ADCSRA |= (1 << ADSC);
while (ADCSRA & (1 << ADSC));
return ADCW;
}
/*
* clock_tick
* Adds a second to the clock.
*/
void clock_tick(void) {
seconds++;
if (seconds == 60) {
seconds = 0;
minutes++;
if (minutes == 60) {
minutes = 0;
hours++;
if (hours == 24) {
hours = 0;
}
}
}
}
/*
* display_active_col
* Deactivates the old column and displays the next one.
*/
void display_active_col(void) {
// shut down all rows
PORTC |= 0x1f;
// shut down active column
if (active_col > 5) {
PORTD &= ~0x0c; // switch off both pins
}
else {
PORTB &= ~(1 << active_col);
}
// next column
active_col = (active_col+1) % 8;
// output all rows
PORTC = ~faces[active_face][active_col];
// activate column
if (active_col == 6) {
PORTD |= 0x04;
}
else if (active_col == 7) {
PORTD |= 0x08;
}
else {
PORTB |= (1 << active_col);
}
}
int main(void) {
uint8_t i = 0;
uint16_t sum = 0;
uint16_t amplitude = 0;
// timer 0 setup, prescaler 8
TCCR0B |= (1 << CS00);
// enable timer 0 interrupt
TIMSK0 |= (1 << TOIE0);
DDRC |= 0x1f; // PC0-PC4: row 0-4
DDRB |= 0x3f; // PB0-PB5: col 0-5
DDRD |= 0x1c; // PD2-PD3: col 6-7, PD4: debug LED
sei();
while (1) {
// do sampling and sum the amplitude
for (i = 0; i < MAX_SAMPLES; i++) {
amplitude = get_adc();
if (amplitude > 512 + DELTA) {
amplitude -= (512 + DELTA);
}
else if (amplitude < 512 - DELTA) {
amplitude = 512 - amplitude - DELTA;
}
else {
amplitude = 0;
}
sum += amplitude;
_delay_ms(1);
}
sum = sum / MAX_SAMPLES;
sum = sum / SCALE; // scale down to map to faces
active_face = (sum >= MAX_FACES) ? MAX_FACES - 1 : sum;
}
return 0;
}

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