diff --git a/SW/rs485_rele_esplan/rs485_rele_esplan.ino b/SW/rs485_rele_esplan/rs485_rele_esplan.ino
new file mode 100755
index 0000000..8aaa189
--- /dev/null
+++ b/SW/rs485_rele_esplan/rs485_rele_esplan.ino
@@ -0,0 +1,59 @@
+//  ESPLan + https://www.laskakit.cz/8-kanalu-12v-rele-modul-250vac-10a--rs485--din/
+
+byte open1ch[] = {0x01, 0x06, 0x00, 0x01, 0x01, 0x00};
+byte close1ch[] = {0x01, 0x06, 0x00, 0x01, 0x02, 0x00};
+
+byte openAll[] = {0x01, 0x06, 0x00, 0x00, 0x07, 0x00};
+byte closeAll[] = {0x01, 0x06, 0x00, 0x00, 0x08, 0x00};
+
+
+void setup(){
+  Serial.begin(115200);
+
+  Serial1.begin(9600, SERIAL_8N1, 36, 4); //ESP32 RX1 IO36, TX1 IO4
+
+//  sendData(openAll, sizeof(openAll));  //  Sepne vsechny rele
+//  delay(1000);
+//  sendData(closeAll, sizeof(closeAll));  //  Rozepne vsechny rele
+//  delay(1000);
+  sendData(open1ch, sizeof(open1ch));  //  Sepne rele 1
+  delay(1000);
+  sendData(close1ch, sizeof(close1ch));  //  Rozepne rele 1
+}
+
+void loop(){
+
+}
+
+void sendData(byte d[], int i){
+  byte crc[2];
+
+  uint16_t crcc = calcCRC(d, i);
+  uint8_t crc_l = (uint8_t)(crcc >> 8);
+  uint8_t crc_h = (uint8_t)crcc;
+  d[6] = crc_h;
+  d[7] = crc_l;
+
+  Serial1.write(d, i+2);
+}
+
+unsigned short calcCRC(const unsigned char *indata, int len){
+  unsigned short crc=0xffff;
+  unsigned char temp;
+  int n;
+  while(len--){
+    crc=*indata^crc;
+    for(n=0;n<8;n++){
+      char TT;
+      TT=crc&1;
+      crc=crc>>1;
+      crc=crc&0x7fff;
+      if (TT==1){
+        crc=crc^0xa001;
+        crc=crc&0xffff;
+      }
+    }
+    indata++;
+  }
+  return crc;
+}