diff --git a/main/knob.cpp b/main/knob.cpp
new file mode 100644
index 0000000..4c37075
--- /dev/null
+++ b/main/knob.cpp
@@ -0,0 +1,46 @@
+#include <stdlib.h>
+
+#include "hal.h"
+
+#include "knob.h"
+
+#include "format.h"
+
+#ifdef WITH_KNOB
+
+volatile uint8_t KNOB_Tick=15;
+
+#ifdef __cplusplus
+  extern "C"
+#endif
+void vTaskKNOB(void* pvParameters)
+{
+
+  uint8_t Tick=KNOB_Tick;
+  for( ; ; )
+  { vTaskDelay(40);
+#ifdef WITH_STM32
+    xSemaphoreTake(ADC1_Mutex, portMAX_DELAY);            // request
+    uint16_t Knob     = ADC_Read_Knob();                  // read knob position: 0..2047
+    xSemaphoreGive(ADC1_Mutex);
+#endif
+#ifdef WITH_ESP32
+    uint16_t Knob = KnobSense();
+#endif
+    uint16_t PrevKnob = ((uint16_t)Tick<<8)+0x80;
+     int16_t Err      = Knob-PrevKnob;
+    if(abs(Err)>=(0x80+0x20))                              // 0x20 is the histeresis to avoid noisy input
+    { KNOB_Tick = (Tick = (Knob>>8)); Play(Play_Vol_1 | Play_Oct_1 | Tick, 5);
+      // if(KNOB_Tick&1) LED_BAT_On();
+      //           else LED_BAT_Off();
+      // xSemaphoreTake(CONS_Mutex, portMAX_DELAY);
+      // Format_UnsDec(CONS_UART_Write, (uint16_t)Tick);
+      // CONS_UART_Write('\r'); CONS_UART_Write('\n');
+      // xSemaphoreGive(CONS_Mutex);
+    }
+
+  }
+
+}
+
+#endif // WITH_KNOB