diff --git a/code/main/server_main.cpp b/code/main/server_main.cpp
index 7d24f2b0..d60b2aa1 100644
--- a/code/main/server_main.cpp
+++ b/code/main/server_main.cpp
@@ -14,6 +14,8 @@
 #include "esp_wifi.h"
 
 #include "server_tflite.h"
+#include "esp_log.h"
+
 
 //#define DEBUG_DETAIL_ON      
 
@@ -38,11 +40,11 @@ esp_err_t info_get_handler(httpd_req_t *req)
 
     if (httpd_req_get_url_query_str(req, _query, 200) == ESP_OK)
     {
-        printf("Query: "); printf(_query); printf("\n");
+        ESP_LOGD(TAG_SERVERMAIN, "Query: %s", _query);
         
         if (httpd_query_key_value(_query, "type", _valuechar, 30) == ESP_OK)
         {
-            printf("type is found"); printf(_valuechar); printf("\n"); 
+            ESP_LOGD(TAG_SERVERMAIN, "type is found: %s", _valuechar);
             _task = std::string(_valuechar);
         }
     };
@@ -153,7 +155,7 @@ esp_err_t hello_main_handler(httpd_req_t *req)
 #endif
 
     char filepath[50];
-    printf("uri: %s\n", req->uri);
+    ESP_LOGD(TAG_SERVERMAIN, "uri: %s\n", req->uri);
     int _pos;
     esp_err_t res;
 
@@ -162,7 +164,7 @@ esp_err_t hello_main_handler(httpd_req_t *req)
 
     const char *filename = get_path_from_uri(filepath, base_path,
                                              req->uri - 1, sizeof(filepath));    
-    printf("1 uri: %s, filename: %s, filepath: %s\n", req->uri, filename, filepath);
+    ESP_LOGD(TAG_SERVERMAIN, "1 uri: %s, filename: %s, filepath: %s", req->uri, filename, filepath);
 
     if ((strcmp(req->uri, "/") == 0))
     {
@@ -180,13 +182,13 @@ esp_err_t hello_main_handler(httpd_req_t *req)
     }
 
     if (filetosend == "/sdcard/html/index.html" && isSetupModusActive()) {
-        printf("System is in setup mode --> index.html --> setup.html");
+        ESP_LOGD(TAG_SERVERMAIN, "System is in setup mode --> index.html --> setup.html");
         filetosend = "/sdcard/html/setup.html";
     }
 
-    printf("Filename: %s\n", filename);
+    ESP_LOGD(TAG_SERVERMAIN, "Filename: %s", filename);
     
-    printf("File requested: %s\n", filetosend.c_str());    
+    ESP_LOGD(TAG_SERVERMAIN, "File requested: %s", filetosend.c_str());
 
     if (!filename) {
         ESP_LOGE(TAG_SERVERMAIN, "Filename is too long");
@@ -216,17 +218,17 @@ esp_err_t hello_main_handler(httpd_req_t *req)
 esp_err_t img_tmp_handler(httpd_req_t *req)
 {
     char filepath[50];
-    printf("uri: %s\n", req->uri);
+    ESP_LOGD(TAG_SERVERMAIN, "uri: %s", req->uri);
 
     char *base_path = (char*) req->user_ctx;
     std::string filetosend(base_path);
 
     const char *filename = get_path_from_uri(filepath, base_path,
                                              req->uri  + sizeof("/img_tmp/") - 1, sizeof(filepath));    
-    printf("1 uri: %s, filename: %s, filepath: %s\n", req->uri, filename, filepath);
+    ESP_LOGD(TAG_SERVERMAIN, "1 uri: %s, filename: %s, filepath: %s", req->uri, filename, filepath);
 
     filetosend = filetosend + "/img_tmp/" + std::string(filename);
-    printf("File to upload: %s\n", filetosend.c_str());    
+    ESP_LOGD(TAG_SERVERMAIN, "File to upload: %s", filetosend.c_str());
 
     esp_err_t res = send_file(req, filetosend); 
     if (res != ESP_OK)
@@ -245,17 +247,17 @@ esp_err_t img_tmp_virtual_handler(httpd_req_t *req)
 
     char filepath[50];
 
-    printf("uri: %s\n", req->uri);
+    ESP_LOGD(TAG_SERVERMAIN, "uri: %s", req->uri);
 
     char *base_path = (char*) req->user_ctx;
     std::string filetosend(base_path);
 
     const char *filename = get_path_from_uri(filepath, base_path,
                                              req->uri  + sizeof("/img_tmp/") - 1, sizeof(filepath));    
-    printf("1 uri: %s, filename: %s, filepath: %s\n", req->uri, filename, filepath);
+    ESP_LOGD(TAG_SERVERMAIN, "1 uri: %s, filename: %s, filepath: %s", req->uri, filename, filepath);
 
     filetosend = std::string(filename);
-    printf("File to upload: %s\n", filetosend.c_str()); 
+    ESP_LOGD(TAG_SERVERMAIN, "File to upload: %s", filetosend.c_str());
 
     if (filetosend == "raw.jpg")
     {
diff --git a/code/test/components/jomjol-flowcontroll/test_flow_postrocess_helper.cpp b/code/test/components/jomjol-flowcontroll/test_flow_postrocess_helper.cpp
index c37e0577..01656575 100644
--- a/code/test/components/jomjol-flowcontroll/test_flow_postrocess_helper.cpp
+++ b/code/test/components/jomjol-flowcontroll/test_flow_postrocess_helper.cpp
@@ -1,5 +1,7 @@
 #include "test_flow_postrocess_helper.h"
+#include "esp_log.h"
 
+static const char *TAG_POSTPROC_HELPER = "test_flow_postproc_helper";
 
 UnderTestPost* setUpClassFlowPostprocessing(t_CNNType digType, t_CNNType anaType)
 {
@@ -36,7 +38,7 @@ std::string process_doFlow(std::vector<float> analog, std::vector<float> digits,
             bool checkConsistency, bool extendedResolution, int decimal_shift) {
     // setup the classundertest
     UnderTestPost* _undertestPost = init_do_flow(analog, digits, digType, checkConsistency, extendedResolution, decimal_shift);
-    printf("SetupClassFlowPostprocessing completed.\n");
+    ESP_LOGD(TAG_POSTPROC_HELPER, "SetupClassFlowPostprocessing completed.");
 
     string time;
     // run test
@@ -81,7 +83,7 @@ UnderTestPost* init_do_flow(std::vector<float> analog, std::vector<float> digits
             gen_analog->ROI.push_back(anaROI);
         }
     }
-    printf("Setting up of ROIs completed.\n");
+    ESP_LOGD(TAG_POSTPROC_HELPER, "Setting up of ROIs completed.");
 
     _undertestPost->InitNUMBERS();
    
@@ -95,7 +97,7 @@ UnderTestPost* init_do_flow(std::vector<float> analog, std::vector<float> digits
 
 void setPreValue(UnderTestPost* _underTestPost, double _preValue) {
         if (_preValue>0) {
-        printf("preValue=%f", _preValue);
+        ESP_LOGD(TAG_POSTPROC_HELPER, "preValue=%f", _preValue);
         std::vector<NumberPost*>* NUMBERS = _underTestPost->GetNumbers();    
         for (int _n = 0; _n < (*NUMBERS).size(); ++_n) {
             (*NUMBERS)[_n]->PreValue = _preValue;
@@ -104,7 +106,7 @@ void setPreValue(UnderTestPost* _underTestPost, double _preValue) {
 }
 
 void setAllowNegatives(UnderTestPost* _underTestPost, bool _allowNegatives) {
-        printf("checkConsistency=true\n");
+        ESP_LOGD(TAG_POSTPROC_HELPER, "checkConsistency=true");
         std::vector<NumberPost*>* NUMBERS = _underTestPost->GetNumbers();    
         for (int _n = 0; _n < (*NUMBERS).size(); ++_n) {
             (*NUMBERS)[_n]->AllowNegativeRates = _allowNegatives;
@@ -114,7 +116,7 @@ void setAllowNegatives(UnderTestPost* _underTestPost, bool _allowNegatives) {
 
 void setConsitencyCheck(UnderTestPost* _underTestPost, bool _checkConsistency) {
         if (_checkConsistency) {
-        printf("checkConsistency=true\n");
+        ESP_LOGD(TAG_POSTPROC_HELPER, "checkConsistency=true");
         std::vector<NumberPost*>* NUMBERS = _underTestPost->GetNumbers();    
         for (int _n = 0; _n < (*NUMBERS).size(); ++_n) {
             (*NUMBERS)[_n]->checkDigitIncreaseConsistency = true;
@@ -136,7 +138,7 @@ void setDecimalShift(UnderTestPost* _underTestPost, int _decimal_shift) {
     if (_decimal_shift!=0) {
         std::vector<NumberPost*>* NUMBERS = _underTestPost->GetNumbers();    
         for (int _n = 0; _n < (*NUMBERS).size(); ++_n) {
-            printf("Setting decimal shift on number: %d to %d\n", _n, _decimal_shift);
+            ESP_LOGD(TAG_POSTPROC_HELPER, "Setting decimal shift on number: %d to %d", _n, _decimal_shift);
             (*NUMBERS)[_n]->DecimalShift = _decimal_shift;
             (*NUMBERS)[_n]->DecimalShiftInitial = _decimal_shift;   
         }       
@@ -147,7 +149,7 @@ void setAnalogdigitTransistionStart(UnderTestPost* _underTestPost, float _analog
     if (_analogdigitTransistionStart!=0) {
         std::vector<NumberPost*>* NUMBERS = _underTestPost->GetNumbers();    
         for (int _n = 0; _n < (*NUMBERS).size(); ++_n) {
-            printf("Setting decimal shift on number: %d to %f\n", _n, _analogdigitTransistionStart);
+            ESP_LOGD(TAG_POSTPROC_HELPER, "Setting decimal shift on number: %d to %f", _n, _analogdigitTransistionStart);
             (*NUMBERS)[_n]->AnalogDigitalTransitionStart = _analogdigitTransistionStart; 
         }       
     }