From 7ddc7e8f71d302d74bcfac35c1c4860cb1c559ba Mon Sep 17 00:00:00 2001
From: Wolfgang Hottgenroth <wolfgang.hottgenroth@icloud.com>
Date: Thu, 13 Jun 2024 17:53:12 +0200
Subject: [PATCH] frequency to divider calculation

---
 generator.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/generator.c b/generator.c
index f341b01..d4037d5 100644
--- a/generator.c
+++ b/generator.c
@@ -4,11 +4,28 @@
 #include "generator.h"
 
 
+
+
+
+
+const float BASE_FREQUENCY = 2457600.0;
+const float MAIN_DIVIDER = 8388606.0;  // 2^23
+
+
+static uint16_t frequencyToDivider(uint16_t freq) {
+  float f = (float) freq;
+  float n = (f * MAIN_DIVIDER) / BASE_FREQUENCY;
+  uint16_t i = (uint16_t) n;
+  if (n - i >= 0.5) {
+    i += 1;
+  }
+  return i;
+}
+
 void generatorInit() {
   P1DIR |= BIT0 | BIT1 | BIT2 | BIT3;
   P1OUT |= BIT0 | BIT1 | BIT2 | BIT3;
 
-
-  genShifter(0, 0x8002);
+  genShifter(0, frequencyToDivider(441));
 }