diff --git a/main/power_profiler.c b/main/power_profiler.c
index 650d222..c970451 100644
--- a/main/power_profiler.c
+++ b/main/power_profiler.c
@@ -7,18 +7,22 @@
 #include "esp_adc/adc_cali.h"
 #include "esp_adc/adc_continuous.h"
 #include "esp_adc/adc_oneshot.h"
+#include "esp_intr_alloc.h"
 #include "esp_log.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "freertos/portmacro.h"
 
 #include "hal/adc_types.h"
+#include "hal/gpio_types.h"
 #include "resistor_ranges.h"
 #include "measure.h"
 #include "soc/soc_caps.h"
 
 #define TAG "main"
 
+#define OVERRANGE_PIN 4
+
 enum ranges {R1, R10, R100, R_NUM};
 
 resistor_range ranges[] = {
@@ -87,7 +91,27 @@ static bool IRAM_ATTR on_conv_done(adc_continuous_handle_t handle, const adc_con
   return false;
 }
 
+char overrange_flag = 0;
+
+static void IRAM_ATTR overrange_handler(void* arg)
+{
+  overrange_flag = 1;
+}
+
 void app_main(void){
+  gpio_config_t overrange_input = {
+    .intr_type = GPIO_INTR_POSEDGE,
+    .mode = GPIO_MODE_INPUT,
+    .pin_bit_mask = 1ULL << OVERRANGE_PIN,
+    .pull_down_en = 0,
+    .pull_up_en = 0,
+  };
+  gpio_config(&overrange_input);
+
+  gpio_install_isr_service(0);
+
+  gpio_isr_handler_add(OVERRANGE_PIN, overrange_handler, NULL);
+  
   set_resistor_gpio(ranges, R100);
   
   activate_range(ranges, R100, R100);
@@ -127,6 +151,9 @@ void app_main(void){
       ESP_ERROR_CHECK(adc_cali_raw_to_voltage(adc_conv_h[i], meas_res_buff[i]/meas_nb_buff[i], &mv));
       ESP_LOGI(TAG, "IN %d : %d mV (%d / %d)", i, mv, meas_res_buff[i], meas_nb_buff[i]);
     }
+
+    ESP_LOGI(TAG, "overrange %d", overrange_flag);
+    overrange_flag = 0;
     
     //activate_range(ranges, r_ind, R100);
     vTaskDelay(5000 / portTICK_PERIOD_MS);