diff --git a/platformio.ini b/platformio.ini
index db1f4b4..eb6a732 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -9,8 +9,8 @@
 ; http://docs.platformio.org/page/projectconf.html
 
 [env:heltec_wifi_lora_32]
-;platform = https://github.com/platformio/platform-espressif32.git#feature/stage
-platform = espressif32
+platform = https://github.com/platformio/platform-espressif32.git#feature/stage
+;platform = espressif32
 board = heltec_wifi_lora_32
 board_f_cpu = 240000000L
 board_f_flash = 80000000L
diff --git a/src/hardware.h b/src/hardware.h
index 12c66b4..956dc7c 100644
--- a/src/hardware.h
+++ b/src/hardware.h
@@ -17,6 +17,7 @@ static constexpr uint8_t ext_wakeup_pin_1 = sensorPin;
 static constexpr uint8_t ext_wakeup_pin_2 = 0;
 
 static constexpr uint32_t secondsToSleep = 15*60;
+static constexpr uint32_t stayOnTime = 3*60*1000;
 static constexpr int batteryLimit = 2800;
 
 #define SX1276_SCK 5
diff --git a/src/main.cpp b/src/main.cpp
index 3f667cb..711553a 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -30,6 +30,9 @@
 
 #include "driver/rtc_io.h"
 
+#include <WiFi.h>
+#include <WiFiUdp.h>
+
 #include "main.h"
 #include "hardware.h"
 #include "mp3.h"
@@ -50,6 +53,7 @@ U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ 16, /* clock=*/ 15
 char timeStr[20];
 char weatherStr[32];
 char statusStr[32];
+unsigned char udprecvbuf[1460];
 RTC_DATA_ATTR static int boot_count = 0;
 RTC_DATA_ATTR struct tm alarmTime;
 RTC_DATA_ATTR bool alarmArmed = false;
@@ -63,6 +67,7 @@ MP3 mp3;
 Rotary rotary;
 Screen* screen;
 Led led;
+WiFiUDP udp;
 
 menuType menuChange = eNone;
 uint32_t lastButtonPress = 0;
@@ -77,6 +82,9 @@ String weatherTopic;
 String statusTopic;
 String sensorTopic;
 
+const IPAddress udpMulticastAddress(239,255,255,245);
+const uint16_t udpMulticastPort = 5555;
+
 void setup() {
   // gpio configuration
 //  rtc_gpio_deinit((gpio_num_t)buttonPin);
@@ -177,7 +185,8 @@ void setup() {
   screen->draw();
   menuChange = eMainScreen;
   u8g2.setContrast(127);
-
+//  U8X8_CA(0x08d, 0x010);   /* [2] charge pump setting (p62): 0x014 enable, 0x010 disable */
+//  U8X8_CA(0xd9, 0x22);     /* [2] pre-charge period 0x022/f1*/
 
   //Set up the Callbacks for the MQTT instance. Refer to the Async MQTT Client documentation
   // TODO: We should do this actually _before_ connecting the mqtt client...
@@ -206,11 +215,22 @@ void setup() {
   localtime_r(&now, &timeinfo);
   strftime(timeStr, sizeof(timeStr), "%H:%M:%S", &timeinfo);
 
-  if (timeinfo.tm_hour < 7 || timeinfo.tm_hour > 23) u8g2.setContrast(1);
-  else u8g2.setContrast(127);
+  if (timeinfo.tm_hour < 7 || timeinfo.tm_hour >= 22) {
+    Serial.println("night mode");
+    u8g2.setContrast(1);
+    u8x8_cad_StartTransfer(u8g2.getU8x8());
+    u8x8_cad_SendCmd( u8g2.getU8x8(), 0xD9);
+    u8x8_cad_SendArg( u8g2.getU8x8(), 0x01);  //max 34 /* [2] pre-charge period 0x022/f1*/
+    u8x8_cad_EndTransfer(u8g2.getU8x8());
+//    u8x8_cad_StartTransfer(u8g2.getU8x8());
+//    u8x8_cad_SendCmd( u8g2.getU8x8(), 0x8D);
+//    u8x8_cad_SendArg( u8g2.getU8x8(), 0x10);  /* [2] charge pump setting (p62): 0x014 enable, 0x010 disable */
+//    u8x8_cad_EndTransfer(u8g2.getU8x8());
+  } else u8g2.setContrast(127);
 
   mp3.begin();
   led.setup();
+  udp.beginMulticast(udpMulticastAddress, udpMulticastPort);
 
   lastButtonPress = millis();
   rotary.registerCallback(rotation);
@@ -309,7 +329,8 @@ void suspend(uint32_t secondsToSleep) {
 
   esp_sleep_enable_timer_wakeup(1000000LL * secondsToSleep);
   const uint64_t ext_wakeup_rotarybtn_mask = 1ULL << rotaryPinButton;
-  const uint64_t ext_wakeup_sensor_mask = 1ULL << sensorPin;
+//  const uint64_t ext_wakeup_sensor_mask = 1ULL << sensorPin;
+  const uint64_t ext_wakeup_sensor_mask = 0; // disable
   esp_sleep_enable_ext1_wakeup(ext_wakeup_rotarybtn_mask | ext_wakeup_sensor_mask, ESP_EXT1_WAKEUP_ANY_HIGH);
 
 ////esp_sleep_enable_ext0_wakeup((gpio_num_t)sensorPin, 0);
@@ -404,7 +425,7 @@ void loop()
 
     bool stayAwake = false;
     if (alarmArmed && seconds >= -2*5*60) stayAwake = true;
-    if (!mp3.playing && millis() - lastActive >= 60*1000 && !stayAwake) suspend();
+    if (!mp3.playing && millis() - lastActive >= stayOnTime && !stayAwake) suspend();
 
     Serial.printf("alarm in %f seconds (%d)\n", seconds, alarmArmed);
     if (seconds >= 0 && alarmArmed) {
@@ -438,6 +459,11 @@ void loop()
       sensorON = false;
     }
 
+  // Send a packet
+  udp.beginMulticastPacket();
+  udp.printf("Seconds since boot: %u", millis()/1000);
+  udp.endPacket();
+
   }
 
   if (digitalRead(sensorPin) == HIGH) {
@@ -453,6 +479,13 @@ void loop()
     transmitStatus();
   }
 
+  int lenp = udp.parsePacket();
+  //Serial.println(lenp);
+  while(udp.available()) {
+    int len = udp.read(udprecvbuf, sizeof(udprecvbuf));
+    Serial.printf("udp received %d bytes\n", len);
+  }
+
   if (menuChange != eNone) {
     delete screen;
     if (menuChange == eMainScreen) screen = new MainScreen();