How to set the address
Wire the address pin like this:
SDO: GND → 0x76 · VDDIO → 0x77
Devices that use the same addresses
Two devices on the same bus can’t answer on the same address. These modules from our list use at least one of these addresses:
| Device | What it is | Shared address |
|---|---|---|
| BME280 | temperature, humidity and pressure sensor | 0x76, 0x77 |
| BME688 | AI gas, temperature, humidity and pressure sensor | 0x76, 0x77 |
| BMP280 | pressure and temperature sensor | 0x76, 0x77 |
| BMP388 | pressure and temperature sensor | 0x76, 0x77 |
| MS5611-01BA | barometric pressure sensor (altimeter) | 0x76, 0x77 |
| PCA9685 | 16-channel 12-bit PWM / servo driver | 0x76, 0x77 |
| TCA9548A | 8-channel I2C multiplexer | 0x76, 0x77 |
| BMP180 | pressure and temperature sensor | 0x77 |
If two of them end up on the same address, move one with its address pin, put one behind a TCA9548A multiplexer (0x70–0x77), or use a second I²C bus: the ESP32, ESP32-S3 and RP2040 have two I²C controllers (the ESP32-C3 has one).
Check your whole bus →Add the BME680 and your other modules: the checker finds conflicts, suggests free addresses and sizes the pull-ups.
7-bit and 8-bit address
I²C addresses are 7 bits long. Some datasheets and libraries write them as 8-bit numbers, with the read/write bit added on the right: that is why the same chip can appear as 0x76 or 0xEC. Arduino’s Wire library and ESPHome use the 7-bit form.
| 7-bit | Binary | 8-bit write | 8-bit read |
|---|---|---|---|
| 0x76 | 1110110 | 0xEC | 0xED |
| 0x77 | 1110111 | 0xEE | 0xEF |
Check that it answers
Upload this sketch with the BME680 wired to SDA and SCL: it tries every address the chip can use and prints the one that answers. On an ESP32 the default pins are GPIO21 (SDA) and GPIO22 (SCL); on an Arduino Uno, A4 and A5.
#include <Wire.h>
const byte ADDRS[] = {0x76, 0x77};
void setup() {
Serial.begin(115200);
Wire.begin();
for (byte a : ADDRS) {
Wire.beginTransmission(a);
if (Wire.endTransmission() == 0) {
Serial.print("BME680 answers at 0x");
if (a < 0x10) Serial.print('0');
Serial.println(a, HEX);
return;
}
}
Serial.println("No answer: check the wiring");
}
void loop() {}
In ESPHome the bus is scanned at boot (scan: true is the default): the log lists every address that answers.
i2c:
sda: GPIO21
scl: GPIO22
scan: true
Pull-up resistors
SDA and SCL need pull-up resistors to the supply. Many breakout boards already carry them, often 4.7 kΩ or 10 kΩ, and with several boards on the bus they add up in parallel. The I²C checker works out the allowed range for your bus voltage and speed.
Frequently asked questions
What is the I2C address of the BME680?
0x76 or 0x77, depending on the wiring: SDO: GND → 0x76 · VDDIO → 0x77.
Can I use more than one BME680 on the same bus?
Yes, up to 2, each set to a different address. For more, use a TCA9548A multiplexer or a second I²C bus.
Why doesn’t the BME680 show up in an I2C scan?
Check, in this order: SDA and SCL not swapped; ground shared between the boards; pull-up resistors on SDA and SCL; the module powered at the voltage it is made for; the address pin not left floating; and that your code uses the 7-bit address (0x76), not the 8-bit one (0xEC).
Similar devices
BME280 BME688 BMP180 BMP280 BMP388 CCS811 ENS160 HDC1080 LM75B LPS22HB MCP9808 MS5611-01BA SCD30 SCD40 / SCD41 SEN50 / SEN54 / SEN55 SGP30 SGP40 SGP41 SHT30 / SHT31 / SHT35 SHT40 / SHT41 / SHT43 / SHT45 (SHT4x) SHTC3 Si7021 TMP102 TMP117
Addresses checked against the BME680 datasheet.