#include "mbed.h" #include "spi_init.h" #include "counter.h" #include "Adafruit_SSD1306.h" #define SW_PINS p22, p23, p24, p25 #define SW_PERIOD 20000 // 20ms void tout(void); // Onboard LED DigitalOut alive(LED1); PinName switch_pin[] = { SW_PINS }; Counter *switch_position[4]; Ticker timer; volatile uint16_t switch_count[4] = { 0, 0, 0, 0 }; volatile uint16_t switch_pressed[4] = { 0, 0, 0, 0 }; volatile uint16_t update = 0; uint16_t max_count[4]; // 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) { // Enable ISR for the switch rising edge for (int i = 0; i < 3; ++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.setRotation(2); oled.printf("%ux%u OLED Display\r\n", oled.width(), oled.height()); for (;;) { if (update) { update = 0; oled.setTextCursor(0, 0); //Write the latest switch osciallor count for (int i = 0; i < 3; ++i) { oled.printf("\n%05u ", switch_count[i]); } //Copy the display buffer to the display oled.display(); alive = !alive; } } } //Interrupt Service Routine for the switch sampling timer void tout(void) { // Query how many times switch triggered for (int i = 0; i < 3; ++i) { switch_count[i] = switch_position[i]->read(); switch_position[i]->write(0); if (max_count[i] < switch_count[i]) max_count[i] = switch_count[i]; if (switch_count[i] < (3/5)*max_count[i]) switch_pressed[i] = 1; else if (switch_count[i] > (4/5)*max_count[i]) switch_pressed[i] = 0; } // Update display update = 1; }