diff --git a/src/client.cpp b/src/client.cpp
index 67c1147..a8d28df 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -3,6 +3,7 @@
 #include <FastLED.h>
 
 #include <mbedtls/md.h>
+#include <mbedtls/sha256.h>
 #include <Preferences.h>
 
 #include "version.h"
@@ -74,6 +75,8 @@ class MyClientCallbacks : public NimBLEClientCallbacks {
     }
 };
 
+static MyClientCallbacks clientCallbacks;
+
 static bool isHexKey(const String &hex) {
     for (int i = 0; i < hex.length(); i++) {
         char c = hex.charAt(i);
@@ -117,7 +120,7 @@ static void disconnectClient() {
 
 static bool connectToServer() {
     pClient = NimBLEDevice::createClient();
-    pClient->setClientCallbacks(new MyClientCallbacks());
+    pClient->setClientCallbacks(&clientCallbacks);
 
     if (!pClient->connect(serverAddress)) {
         Serial.println("BLE: connect failed");
@@ -167,7 +170,7 @@ void setup() {
     delay(2000);
     Serial.println("=== SylDa Client ===");
 
-    FastLED.addLeds<NEOPIXEL, LED_PIN>(leds, NUM_LEDS);
+    FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
     leds[0] = CRGB::Red;
     FastLED.show();
 
@@ -266,7 +269,7 @@ void loop() {
                     preferences.putBytes(NVS_KEY_NAME, hmacKey, HMAC_KEY_LEN);
                     preferences.end();
                     keyProvisioned = true;
-                    allProvisioned = keyProvisioned && serverProvisioned;
+                    allProvisioned = keyProvisioned && uuidProvisioned && serverProvisioned;
                     Serial.println("OK");
                     Serial.println("HMAC key stored in NVS");
                     if (allProvisioned && !bleReady) {
@@ -291,7 +294,7 @@ void loop() {
                     preferences.putBytes(NVS_UUID_NAME, deviceUuid, ESP_UUID_LEN);
                     preferences.end();
                     uuidProvisioned = true;
-                    allProvisioned = keyProvisioned && serverProvisioned;
+                    allProvisioned = keyProvisioned && uuidProvisioned && serverProvisioned;
                     Serial.println("OK");
                     Serial.println("UUID stored in NVS");
                 } else {
@@ -306,7 +309,7 @@ void loop() {
                     preferences.putBytes(NVS_SERVER_NAME, serverUuid, ESP_UUID_LEN);
                     preferences.end();
                     serverProvisioned = true;
-                    allProvisioned = keyProvisioned && serverProvisioned;
+                    allProvisioned = keyProvisioned && uuidProvisioned && serverProvisioned;
                     Serial.println("OK");
                     Serial.println("Server UUID stored in NVS");
                     if (allProvisioned && !bleReady) {
@@ -349,14 +352,12 @@ void loop() {
     bool btnActive = (millis() - btnChange > DEBOUNCE_MS) && btnStable;
 
     static bool prevBtnActive = false;
-    static bool buttonToggle = false;
     if (btnActive && !prevBtnActive) {
-        buttonToggle = !buttonToggle;
-        Serial.printf("Button: toggle -> %s\n", buttonToggle ? "ON" : "OFF");
+        Serial.printf("Button: pressed\n");
     }
     prevBtnActive = btnActive;
 
-    bool relay1State = t1Active || buttonToggle;
+    bool relay1State = t1Active || btnActive;
     bool relay2State = t2Active;
 
     if (relay1State || relay2State) {
@@ -369,19 +370,24 @@ void loop() {
     FastLED.show();
 
     if (connected && pCmdChar != nullptr) {
-        if (relay1State != relay1SendState) {
-            uint8_t pkt[HMAC_PKT_SIZE];
-            buildHmacPacket(relay1State ? 0x01 : 0x00, pkt);
-            pCmdChar->writeValue(pkt, HMAC_PKT_SIZE, false);
-            relay1SendState = relay1State;
-            Serial.printf("TX: relay1 %s (seq=%lu)\n", relay1State ? "ON" : "OFF", seq);
-        }
-        if (relay2State != relay2SendState) {
-            uint8_t pkt[HMAC_PKT_SIZE];
-            buildHmacPacket(relay2State ? 0x02 : 0x03, pkt);
-            pCmdChar->writeValue(pkt, HMAC_PKT_SIZE, false);
-            relay2SendState = relay2State;
-            Serial.printf("TX: relay2 %s (seq=%lu)\n", relay2State ? "ON" : "OFF", seq);
+        static uint32_t lastCmd = 0;
+        if (millis() - lastCmd > 200) {
+            if (relay1State != relay1SendState) {
+                uint8_t pkt[HMAC_PKT_SIZE];
+                buildHmacPacket(relay1State ? 0x01 : 0x00, pkt);
+                pCmdChar->writeValue(pkt, HMAC_PKT_SIZE, false);
+                relay1SendState = relay1State;
+                Serial.printf("TX: relay1 %s (seq=%lu)\n", relay1State ? "ON" : "OFF", seq);
+                lastCmd = millis();
+            }
+            if (relay2State != relay2SendState) {
+                uint8_t pkt[HMAC_PKT_SIZE];
+                buildHmacPacket(relay2State ? 0x02 : 0x03, pkt);
+                pCmdChar->writeValue(pkt, HMAC_PKT_SIZE, false);
+                relay2SendState = relay2State;
+                Serial.printf("TX: relay2 %s (seq=%lu)\n", relay2State ? "ON" : "OFF", seq);
+                lastCmd = millis();
+            }
         }
     }