From 12250f63813c329257523e2cb48792c51590dd9e Mon Sep 17 00:00:00 2001 From: Vasil Zlatanov Date: Mon, 8 May 2017 00:48:58 +0100 Subject: Support frequency less than 25Hz --- src/main.cpp | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/src/main.cpp b/src/main.cpp index 19f280d..1af96d5 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -1,4 +1,5 @@ #include "mbed.h" + #include "spi_init.h" #include "counter.h" #include "Adafruit_SSD1306.h" @@ -7,7 +8,8 @@ #define SW_PERIOD 20000 // 20ms void tout(void); -void pwm_invert(void); +void pwm_invert_fast(void); +void pwm_invert_slow(void); // Onboard LED DigitalOut out_wave(LED1); @@ -24,6 +26,7 @@ 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 divider = 0; // Initialise display SPInit gSpi(D_MOSI_PIN, NC, D_CLK_PIN); @@ -31,6 +34,7 @@ Adafruit_SSD1306_Spi oled(gSpi, D_DC_PIN, D_RST_PIN, D_CS_PIN, 64, 128); int main(void) { + out_wave.write(0.5); oled.setRotation(2); wait(0.5); @@ -63,10 +67,10 @@ int main(void) oled.printf("\nF:%u ", frequency); - if (frequency < 25) - pwm.attach_ms(&pwm_invert, 500/frequency); - else - pwm.attach_us(&pwm_invert, 500000/frequency); + if (frequency > 24) + pwm.attach_us(&pwm_invert_fast, 500000/frequency); + else if (frequency > 0) + pwm.attach_us(&pwm_invert_slow, 25000/frequency); //Copy the display buffer to the display oled.display(); @@ -95,6 +99,14 @@ void tout(void) update = 1; } -void pwm_invert(void){ - out_wave = !out_wave; +void pwm_invert_slow(void){ + divider++; + if (divider % 25 == 0){ + divider = 0; + out_wave = !out_wave; + } +} + +void pwm_invert_fast(void){ + out_wave = !out_wave; } -- cgit v1.2.3-54-g00ecf