diff --git a/src/drivers/imu/imu_i2c.c b/src/drivers/imu/imu_i2c.c
index b8254e2..2aa3f2d 100644
--- a/src/drivers/imu/imu_i2c.c
+++ b/src/drivers/imu/imu_i2c.c
@@ -394,12 +394,12 @@ int imu_read(int16_t accel[3], int16_t gyro[3])
     uint8_t raw[12];
     int ret;
 
-    // 자이로 설정: ±2000dps FSR, 100Hz ODR
-    ret = imu_write_reg(REG_GYRO_CONFIG0, 0x09);
+    // 자이로 설정: ±500dps FSR, 50Hz ODR
+    ret = imu_write_reg(REG_GYRO_CONFIG0, IMU_CFG_50HZ_500DPS);
     if (ret) { DBG_PRINTF("[IMU] FAIL — gyro config write (ret=%d)\r\n", ret); return -1; }
 
-    // 가속도 설정: ±4g FSR, 100Hz ODR
-    ret = imu_write_reg(REG_ACCEL_CONFIG0, 0x29);
+    // 가속도 설정: ±4g FSR, 50Hz ODR
+    ret = imu_write_reg(REG_ACCEL_CONFIG0, IMU_CFG_50HZ_4G);
     if (ret) { DBG_PRINTF("[IMU] FAIL — accel config write (ret=%d)\r\n", ret); return -1; }
 
     ret = imu_set_data_big_endian();
@@ -447,10 +447,10 @@ int imu_read_with_temperature(int16_t accel[3], int16_t gyro[3], int16_t *temp_c
         return -EINVAL;
     }
 
-    ret = imu_write_reg(REG_GYRO_CONFIG0, 0x09);
+    ret = imu_write_reg(REG_GYRO_CONFIG0, IMU_CFG_50HZ_500DPS);
     if (ret) { DBG_PRINTF("[IMU] FAIL — gyro config write (ret=%d)\r\n", ret); return -1; }
 
-    ret = imu_write_reg(REG_ACCEL_CONFIG0, 0x29);
+    ret = imu_write_reg(REG_ACCEL_CONFIG0, IMU_CFG_50HZ_4G);
     if (ret) { DBG_PRINTF("[IMU] FAIL — accel config write (ret=%d)\r\n", ret); return -1; }
 
     ret = imu_set_data_big_endian();
diff --git a/src/drivers/imu/imu_i2c.h b/src/drivers/imu/imu_i2c.h
index 2214552..0c19cfe 100644
--- a/src/drivers/imu/imu_i2c.h
+++ b/src/drivers/imu/imu_i2c.h
@@ -28,8 +28,8 @@ int imu_init(void);
  *
  * 센서 설정 → 전원 ON → 80ms 대기 → 12바이트 읽기 → 전원 OFF
  *
- * @param accel  가속도 XYZ (int16, ±4g, 100Hz)
- * @param gyro   자이로 XYZ (int16, ±2000dps, 100Hz)
+ * @param accel  가속도 XYZ (int16, ±4g, 50Hz)
+ * @param gyro   자이로 XYZ (int16, ±500dps, 50Hz)
  * @return 0 성공, 음수 에러
  */
 int imu_read(int16_t accel[3], int16_t gyro[3]);
diff --git a/src/main.h b/src/main.h
index a442444..0f50d2e 100644
--- a/src/main.h
+++ b/src/main.h
@@ -16,9 +16,9 @@
  * Firmware identification : Default values, can be overridden by NVS
  *============================================================================*/
 #define HARDWARE_VERSION        "VB0HW0000"
-#define SERIAL_NUMBER           "VBT260300ZZ"
+#define SERIAL_NUMBER           "VBT2608000Z"
 #define DEFAULT_PASSKEY         "123456"
-#define FIRMWARE_VERSION        "VBTFW0203"
+#define FIRMWARE_VERSION        "VBTFW0204"
 
 /*
 * Firmware Version History
@@ -26,6 +26,8 @@
  * 2026-07-31 | VBTFW0200  | 2.0.0+0       | Initial release
  * 2026-08-05 | VBTFW0201  | 2.0.1+0       | Added allowlist, fixed bond delete issue
  * 2026-08-05 | VBTFW0202  | 2.0.2+0       | Added production command(mpd?)
+ * 2026-08-25 | VBTFW0203  | 2.0.3+0       | Fixed piezo power on/off timing, piezo sweep timing, and BLE settings
+ * 2026-08-28 | VBTFW0204  | 2.0.4+0       | Align IMU direct read(mbb?) FSR with FIFO scale
 */
 
 /*==============================================================================