diff --git a/src/hal/heltecv2.h b/src/hal/heltecv2.h
index ad34f68c..8e6f4812 100644
--- a/src/hal/heltecv2.h
+++ b/src/hal/heltecv2.h
@@ -7,8 +7,16 @@
 
 // Hardware related definitions for Heltec V2 LoRa-32 Board
 
-//#define HAS_BME 0x77  // BME680 sensor on I2C bus (SDI=21/SCL=22); comment out
-//if not present
+// BME680 sensor on I2C bus (SDI=21/SCL=22); comment out if not present
+//#define HAS_BME GPIO_NUM_21, GPIO_NUM_22 // SDA, SCL
+//#define BME_ADDR BME680_I2C_ADDR_PRIMARY // connect SDIO of BME680 to GND
+
+// Of cause, by default the board has no BME680 mounted 
+// a BME680 sensor board maybe connected to I2C (SDA = 4 , and SLC = 15)
+// second it worked if SDIO left unconnected and 0x77 as address was used
+//#define HAS_BME 4, 15 // SDA, SCL
+//#define BME_ADDR BME680_I2C_ADDR_SECONDARY // leave SDIO of BME680 unconnected
+ 
 
 #define HAS_LORA 1       // comment out if device shall not send data via LoRa
 #define CFG_sx1276_radio 1
@@ -18,8 +26,8 @@
 #define HAS_BUTTON KEY_BUILTIN                        // button "PROG" on board
 
 // Pins for I2C interface of OLED Display
-#define MY_OLED_SDA (21)
-#define MY_OLED_SCL (22)
+#define MY_OLED_SDA (4)    // original = 21
+#define MY_OLED_SCL (15)    // original = 22
 #define MY_OLED_RST (16)
 
 // Pins for LORA chip SPI interface come from board file, we need some