diff --git a/adc.c b/adc.c
index 4ee4f8f..a3486eb 100644
--- a/adc.c
+++ b/adc.c
@@ -32,6 +32,8 @@ struct pin_t reset = { .port = GPIO5, .pin = GPIOPIN2 };
 struct pin_t range = { .port = GPIO5, .pin = GPIOPIN6 };
 struct pin_t standby = { .port = GPIO5, .pin = GPIOPIN0 }; // inverted
 
+unsigned int adc_sample_counter = 0;
+
 #ifdef USE_DMA
 static void configure_rx_dma()
 {
@@ -245,5 +247,7 @@ void pin_int0_isr(void)
                                 setup_buffer(NULL);
                         }
                 }
+
+                increment_event_counter(adc_sample_counter);
         }
 }
diff --git a/clock.c b/clock.c
index 5d02afb..08346af 100644
--- a/clock.c
+++ b/clock.c
@@ -1,10 +1,20 @@
+#include <libopencm3/cm3/systick.h>
+
 #include "clock.h"
 #include "config.h"
-
-#include <libopencm3/cm3/systick.h>
+#include "utils.h"
 
 volatile uint32_t msTicks;      /* counts 1ms timeTicks */
 
+volatile struct event_counters event_counters[N_EVENT_COUNTERS];
+unsigned int active_event_counter_index = 0;
+#define active_event_counters (&event_counters[active_event_counter_index])
+
+struct event_counters get_last_event_counters(void)
+{
+    return event_counters[(active_event_counter_index-1) % N_EVENT_COUNTERS];
+}
+
 void init_systick()
 {
     systick_set_reload(CLK_BASE_M4 / 8 / 1000);
@@ -20,4 +30,10 @@ void delay_ms(unsigned int ms) {
 
 void sys_tick_handler() {
     msTicks++;
+
+    if (msTicks % 1024 == 0) {
+        unsigned int next = (active_event_counter_index + 1) % N_EVENT_COUNTERS;
+        memzero((void*) &event_counters[next], sizeof(struct event_counters));
+        active_event_counter_index = next;
+    }
 }
diff --git a/clock.h b/clock.h
index 1b69619..1943732 100644
--- a/clock.h
+++ b/clock.h
@@ -6,3 +6,20 @@ extern volatile uint32_t msTicks;      /* counts 1ms timeTicks */
 void init_systick();
 void delay_ms(unsigned int ms);
 
+struct event_counters {
+    unsigned int feedback_counter;
+    unsigned int adc_sample_counter;
+};
+
+// public
+struct event_counters get_last_event_counters(void);
+
+// private
+#define N_EVENT_COUNTERS 4
+extern volatile struct event_counters event_counters[N_EVENT_COUNTERS];
+extern unsigned int active_event_counter_index;
+
+// public
+#define increment_event_counter(counter) \
+    event_counters[active_event_counter_index].counter++;
+
diff --git a/feedback.c b/feedback.c
index 97a46dd..23bf114 100644
--- a/feedback.c
+++ b/feedback.c
@@ -130,6 +130,7 @@ void do_feedback()
         }
 
         feedback_update();
+        increment_event_counter(feedback_counter);
 }
 
 void timer2_isr(void)
diff --git a/utils.h b/utils.h
new file mode 100644
index 0000000..99a868a
--- /dev/null
+++ b/utils.h
@@ -0,0 +1,8 @@
+#pragma once
+
+#include <string.h>
+
+static inline void memzero(void* ptr, unsigned int size)
+{
+    memset(ptr, 0, size);
+}