Diff: main.cpp

Revision:

0:3ba7ee31812f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Jan 05 12:19:42 2012 +0000
@@ -0,0 +1,68 @@
+#include <mbed.h>
+#include <math.h>
+#define M_2PI 6.28318530717959
+#define FS 20000
+#define WAVE 0
+#define POLY 4
+Serial serial(USBTX, USBRX);
+Ticker ticker;
+AnalogOut analogOut(p18);
+int count;
+float as[POLY];
+int fs[POLY];
+int n;
+
+int a = 0x8000;
+float b = 1.0;
+float c = 1;
+
+void sample()
+{
+    int value = 0;
+
+    for (int i = 0; i < POLY; i++) {
+        value += as[i] * (fs[i] * count % FS) / FS;
+        if (as[i] > 0) {
+            as[i] -= b;
+            if (as[i] < 0) as[i] = 0;
+        } else {
+            as[i] = 0;
+        }
+    }
+    analogOut.write_u16(value);
+    count++;
+}
+
+int main()
+{
+    int freqs[256];
+    freqs[ 49] = 704; freqs[ 50] = 640; freqs[ 51] = 576; freqs[ 52] = 512; freqs[ 53] = 448; freqs[ 54] = 384;
+        freqs[ 55] = 320; freqs[ 56] = 256; freqs[ 57] = 192; freqs[ 48] = 128; freqs[ 45] =  64;
+      freqs[113] = 528; freqs[119] = 480; freqs[101] = 432; freqs[114] = 384; freqs[116] = 336; freqs[121] = 288;
+          freqs[117] = 240; freqs[105] = 192; freqs[111] = 144; freqs[112] =  96; freqs[ 91] =  48;
+        freqs[ 97] = 396; freqs[115] = 360; freqs[100] = 324; freqs[102] = 288; freqs[103] = 252; freqs[104] = 216;
+            freqs[106] = 180; freqs[107] = 144; freqs[108] = 108; freqs[ 59] =  72; freqs[ 39] =  36;
+          freqs[122] = 297; freqs[120] = 270; freqs[ 99] = 243; freqs[118] = 216; freqs[ 98] = 189; freqs[110] = 162;
+              freqs[109] = 135; freqs[ 44] = 108; freqs[ 46] =  81; freqs[ 47] =  54; freqs[ 32] =  27;
+    serial.printf("\033[2J");
+    ticker.attach_us(&sample, 1000 * 1000 / FS);
+    while (int i = serial.getc()) {
+        if (i == 27) {
+            serial.getc(); serial.getc(); i = serial.getc() - 48; serial.getc();
+            if (i == 1) a >>= 1;
+            if (i == 2) a <<= 1;
+            if (i == 3) b *= 1.2;
+            if (i == 4) b /= 1.2;
+            if (i == 5) c = 0;
+            if (i == 7) c = 1;
+            serial.printf("i = %d; a = %05X; b = %f\r\n", i, a, b);
+            continue;
+        }
+        as[n] = a;
+        fs[n] = freqs[i] * 2;
+        serial.printf("%d:%d\r\n", i, freqs[i]);
+        if (c) n = (n + 1) % POLY;
+    }
+    ticker.detach();
+    analogOut.write_u16(0);
+}