diff --git a/soft/src/freq_counter.c b/soft/src/freq_counter.c
deleted file mode 100644
index 0351ea1..0000000
--- a/soft/src/freq_counter.c
+++ /dev/null
@@ -1,43 +0,0 @@
-#include <freq_counter.h>
-
-void freq_counter_init ( struct freq_counter *f, uint32_t cycle_len ) {
-    f->input_initialized = false;
-    f->input_state = false;
-
-    f->counter = 0;
-    f->samples = 0;
-    f->cycle_len = cycle_len;
-
-    f->new_measurement = false;
-    f->measurement = 0;
-}
-
-void IRAM_ATTR freq_counter_update ( struct freq_counter *f, bool input ) { 
-    if ( f->input_initialized == false ) {
-        // ignore first input value
-        f->input_state = input;
-        f->input_initialized = true;
-    }
-    if ( f->input_state != input) {
-        f->counter += 1;
-        f->input_state = input;
-    }
-    f->samples += 1;
-    if ( f->samples >= f->cycle_len ) {
-        /* cycle complete */
-        f->measurement = f->counter;
-        f->new_measurement = true;
-        f->samples = 0;
-        f->counter = 0;
-    }
-}
-
-bool freq_counter_get_measurement( struct freq_counter *f, uint32_t *measurement) {
-    if ( f->new_measurement == true ) {
-        *measurement = f->measurement; 
-        f->new_measurement = false;
-        return true;
-    } else {
-        return false;
-    }
-}
diff --git a/soft/src/freq_counter.h b/soft/src/freq_counter.h
deleted file mode 100644
index f0b1473..0000000
--- a/soft/src/freq_counter.h
+++ /dev/null
@@ -1,42 +0,0 @@
-#include <stdbool.h>
-#include <stdint.h>
-
-#ifndef FREQ_COUNTER_H
-#define FREQ_COUNTER_H
-
-#ifndef IRAM_ATTR
-    #define IRAM_ATTR __attribute__((section(".iram.text")))
-#endif
-
-struct freq_counter {
-    bool input_initialized; /* false before first update call */
-    bool input_state; /* last update input state */
-
-    uint32_t counter; /* input state changes counter */
-    uint32_t samples; /* input samples counter */
-    uint32_t cycle_len; /* number of samples in one cycle */
-
-    bool new_measurement; /* set to true after updating measurement */
-    uint32_t measurement; /* number of state changes in last complete cycle */
-};
-
-/**
- * @brief initialize frequency counter structure
- *
- * @param cycle_len number of samples in one measurement cycle
- */
-void freq_counter_init ( struct freq_counter *f, uint32_t cycle_len );
-void IRAM_ATTR freq_counter_update ( struct freq_counter *f, bool input );
-
-
-/** 
- * @brief get new measurement from freq_counter
- *  
- * this function should be called at least twice per cycle in order to avoid
- * concurrent rw acces to measurement variable
- * @param measurement is set to new measurement value if returned true
- * @return true if new measurement is available
- */
-bool freq_counter_get_measurement( struct freq_counter *f, uint32_t *measurement);
-
-#endif /* end of include guard: FREQ_COUNTER_H */