From a8609ccd901b1942e862c14205026d841e640add Mon Sep 17 00:00:00 2001
From: EliteTK <tomasz.kramkowski@gmail.com>
Date: Thu, 10 Jul 2014 22:35:35 +0100
Subject: More stuff.

---
 hertz.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 hertz.c

(limited to 'hertz.c')

diff --git a/hertz.c b/hertz.c
new file mode 100644
index 0000000..bed01d9
--- /dev/null
+++ b/hertz.c
@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <math.h>
+
+static long int sfreq;
+
+void playtone(long int, int, long int, float);
+void playtone_pwm(long int, long int, int, long int);
+void sinetone(float, int, float);
+
+int main(int argc, char **argv)
+{
+        if (argc != 2) {
+                fprintf(stderr, "Usage: %s <frequency>\n", argv[0]);
+                exit(1);
+        }
+
+        sfreq = strtol(argv[1], NULL, 10);
+
+        /*for (int i = 1; i < 3000; i++)*/
+                /*sinetone(i, 127, 5);*/
+
+        for (int i = 1; i < 3000; i++)
+                sinetone(i, 127, 1.0/i * 1000.0);
+
+        /*for (int i = 0; i < 1000; i++) {*/
+                /*long int pulse_width = 441;*/
+
+                /*float duty_cycle = (sinf(i / 5.0 * M_PI) + 1.0) / 2.0;*/
+
+                /*for (int ii = 0; ii < ceilf(duty_cycle * pulse_width); ii++)*/
+                        /*putchar(0);*/
+                /*for (int ii = 0; ii < floorf((1.0 - duty_cycle) * pulse_width); ii++)*/
+                        /*putchar(255);*/
+        /*}*/
+
+        /*playtone_pwm(160, 80, 127, 10000);*/
+        /*for (float i = 0; i < 1; i+=0.01)*/
+                /*playtone(100, 127, 10, i);*/
+        return 0;
+}
+
+void playtone(long int freq, int ampl, long int time, float duty_cycle)
+{
+        if (ampl > 127)
+                ampl = 127;
+        long int pulse_width = sfreq / freq;
+
+        long int total_waves = time * freq / 1000;
+
+        for (long int wi = 0; wi < total_waves; wi++) {
+                int i;
+                for (i = 0; i < (int)((float)pulse_width * duty_cycle); i++)
+                        putchar(128-ampl);
+                for (i = 0; i < (int)((float)pulse_width * (1.0 - duty_cycle)); i++)
+                        putchar(255+ampl);
+        }
+}
+
+void playtone_pwm(long int freq, long int freq_pwm, int ampl, long int time)
+{
+        if (ampl > 127)
+                ampl = 127;
+
+        long int pulse_width = sfreq / freq;
+
+        long int total_waves = time * freq / 1000;
+
+        for (long int wi = 0; wi < total_waves; wi++) {
+                int i;
+                float pulse_proportion = (sinf((float)wi / (float)total_waves * time / freq_pwm * 2 * M_PI) + 1) / 2;
+                for (i = 0; i < (int)((float)pulse_width * pulse_proportion); i++)
+                        putchar(128-ampl);
+                for (i = 0; i < (int)((float)pulse_width * (1.0 - pulse_proportion)); i++)
+                        putchar(255+ampl);
+        }
+}
+
+void sinetone(float freq, int ampl, float time)
+{
+        if (ampl > 127) ampl = 127;
+
+        float wave_length = sfreq / freq;
+
+        for (long int wi = 0; wi < time * sfreq / 1000; wi++)
+                putchar((char)((sinf((float)wi / wave_length * M_PI_2 * 4) + 1) * ampl));
+}
-- 
cgit v1.2.3-54-g00ecf