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#include "mbed.h"
#include "spi_init.h"
#include "counter.h"
#include "Adafruit_SSD1306.h"
#define SW_PINS p24, p23, p22, p21
#define SW_PERIOD 20000 // 20ms
void tout(void);
void square(void);
void triangle(void);
void sine(void);
// Onboard LED
AnalogOut out_wave(p18);
PinName switch_pin[] = { SW_PINS };
Counter *switch_position[4];
Ticker timer;
Ticker pwm;
volatile uint16_t switch_count[4] = { 0, 0, 0, 0 };
volatile uint16_t switch_pressed[4] = { 0, 0, 0, 0 };
volatile uint16_t last_pressed[4] = { 0, 0, 0, 0 };
uint16_t current_f[4] = { 0, 0, 0, 0 };
volatile uint16_t update = 0;
volatile uint16_t amp = 0;
const double pi = 3.141592653589793238462;
const double offset = 65535/2;
double rads = 0.0;
uint16_t sample = 0;
// Initialise display
SPInit gSpi(D_MOSI_PIN, NC, D_CLK_PIN);
Adafruit_SSD1306_Spi oled(gSpi, D_DC_PIN, D_RST_PIN, D_CS_PIN, 64, 128);
int main(void)
{
uint16_t frequency = 0;
uint16_t old_frequency = 0;
out_wave.write(0.5);
oled.setRotation(2);
wait(0.5);
// Enable ISR for the switch rising edge
for (int i = 0; i < 4; ++i) {
switch_position[i] = new Counter(switch_pin[i]);
}
//Attach switch sampling timer ISR to the timer instance with the required period
timer.attach_us(&tout, SW_PERIOD);
oled.clearDisplay();
oled.printf("%ux%u Group Ay08-04\r\n", oled.width(), oled.height());
for (;;) {
if (update) {
update = 0;
oled.setTextCursor(0, 0);
//Write the latest switch osciallor count
for (int i = 3; i >= 0; --i) {
current_f[i] += (switch_pressed[i] && !last_pressed[i]);
if (current_f[i] > 9)
current_f[i] = 0;
oled.printf("\nS:%u C:%05u N:%u", switch_pressed[i], switch_count[i], current_f[i]);
}
old_frequency = frequency;
frequency = 1000*current_f[3] + 100*current_f[2] + 10*current_f[1] + current_f[0];
if (frequency != old_frequency){
oled.printf("\nF:%u ", frequency);
if (frequency)
pwm.attach_us(&sine, 1000000/(frequency*360));
}
//Copy the display buffer to the display
oled.display();
}
}
}
//Interrupt Service Routine for the switch sampling timer
void tout(void)
{
// Query how many times switch triggered
for (int i = 0; i < 4; ++i) {
switch_count[i] = switch_position[i]->read();
switch_position[i]->write(0);
last_pressed[i] = switch_pressed[i];
if (switch_count[i] < 600)
switch_pressed[i] = 1;
else if (switch_count[i] > 700)
switch_pressed[i] = 0;
}
// Update display
update = 1;
}
/*
void square(void){
out_wave = !out_wave;
}
*/
void triangle(void){
amp++;
out_wave = (float) amp/256;
if (amp == 256)
amp = 0;
}
void sine(void){
rads = (pi * amp) / 180.0f;
sample = (uint16_t)(0.5f * (offset * (cos(rads + pi))) + offset);
out_wave.write_u16(sample);
amp++;
if(amp == 360)
amp = 0;
}
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