diff --git a/inc/rs485.h b/inc/rs485.h
index 8040541..d0496b6 100644
--- a/inc/rs485.h
+++ b/inc/rs485.h
@@ -28,5 +28,6 @@
 
 void rs485_config(void);
 void process_command(char *cmd);
+uint8_t calculate_crc(uint8_t package_header[3], uint8_t package_data[], size_t data_length);
 
 #endif //RS485_H
\ No newline at end of file
diff --git a/src/rs485.c b/src/rs485.c
index 73e93e0..5698897 100644
--- a/src/rs485.c
+++ b/src/rs485.c
@@ -35,9 +35,21 @@ void rs485_config(void) {
 }
 
 void process_command(char *cmd) {
+    uint8_t package_header[3] = {0xB5, 0xF0, 0x04};
+    uint8_t package_data[4] = {0};
+
+    package_data[0] = (g_eddy_current_value_uint32 >> 24) & 0xFF;
+    package_data[1] = (g_eddy_current_value_uint32 >> 16) & 0xFF;
+    package_data[2] = (g_eddy_current_value_uint32 >> 8) & 0xFF;
+    package_data[3] = g_eddy_current_value_uint32 & 0xFF;
+
+
     if (strncmp(cmd, "M1", 2) == 0) {
         // printf("M1 -=-=- OK!\r\n");
-        printf("EddyCurrent: %lu\r\n", g_eddy_current_value_uint32);
+        // printf("EddyCurrent: %lu\r\n", g_eddy_current_value_uint32);
+        printf("%x%x%x", package_header[0], package_header[1], package_header[2]);
+        printf("%x%x%x%x", package_data[0], package_data[1], package_data[2], package_data[3]);
+        printf("%x\r\n", calculate_crc(package_header, package_data, 4));
     } else if (strncmp(cmd, "M2", 2) == 0) {
         // printf("M2 -=-=- OK!\r\n");
         printf("Temperature: %lu\r\n", g_temperature_uint32);