From 6e48604f22cf35ad115a2b87b27bb7d28bc0e2e8 Mon Sep 17 00:00:00 2001
From: Eduard Iten <eduard@iten.pro>
Date: Sun, 2 Aug 2026 11:19:48 +0200
Subject: [PATCH] Added readme with comments for the firmware

---
 README.md | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 README.md

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..ec4b521
--- /dev/null
+++ b/README.md
@@ -0,0 +1,30 @@
+für zephr:
+```
+#include <zephyr/kernel.h>
+#include <zephyr/arch/cpu.h>
+
+static volatile uint16_t target_val = 0;
+static uint16_t akku = 0;
+
+// Direct ISR deklarieren – minimaler Overhead!
+ISR_DIRECT_DECLARE(my_pwm_dither_isr)
+{
+    // 1. Hardware Interrupt-Flag löschen (direkt übers CMSIS-Register)
+    TIMx->SR = ~TIM_SR_UIF;
+
+    // 2. Deine Akku-Rechnung
+    akku += target_val;
+    TIMx->CCR1 = (akku >> 6);
+    akku &= 0x3F;
+
+    // 3. Kein Reschedule nötig, da wir keine Zephyr-API in der ISR aufrufen
+    return 0; 
+}
+
+void init_pwm_dither(void)
+{
+    // Interrupt in Zephyr registrieren (Priority z.B. 1 oder 2)
+    IRQ_DIRECT_CONNECT(TIMx_IRQn, 1, my_pwm_dither_isr, 0);
+    irq_enable(TIMx_IRQn);
+}
+```