I’ll add one comparison guide using Bosch’s datasheets, with particular attention to footprint and pinout compatibility. I’ll leave all existing project files unchanged.
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"BME280 vs BME680 Comparison" completed.
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Referenced guidance.
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Verify Bosch datasheets, package pinouts, and the existing guide.
Create one comparison guide without changing existing project files.
Check the saved guide against the data and formatting rules.
Average, sleep, and peak-current comparisons and battery-life ratios: matched operating conditions were not established.
Accuracy rankings, gas-concentration/equivalent-CO₂ values, exact heater profiles, and detailed assembly geometry: sufficient primary-source comparison evidence was not established.
Pinout risk: The pin functions match by number, but the packages differ. They are not same-footprint drop-in replacements; replacement requires a footprint change and firmware updates.
In bme280 vs bme680, the main difference is BME680's heated gas sensor alongside humidity, pressure, and temperature sensing. Choose BME280 for environmental measurements alone, or BME680 when your application also needs a gas-resistance signal and its processing.
Quick answer
Table
Choose BME280 if...
Choose BME680 if...
You need humidity, pressure, and temperature without gas sensing.
You also need gas-resistance measurement.
You want to avoid gas-heater scheduling and gas-signal processing.
You can accommodate heater operation and gas-signal processing.
You are retaining a validated BME280 board.
You can redesign the footprint and validate new firmware.
These are selection recommendations for Bosch's bare BME280 and BME680 ICs in their documented metal-lid LGA packages, not breakout boards or a comparison with BME688. Their channel sets and BME680 heater operation are manufacturer-defined.
Electrical comparison: BME280 vs BME680
Supply rows compare recommended operating limits, not absolute-maximum stress ratings or sensor-accuracy tests. Power architecture is compared qualitatively: environmental-only operation and heated-gas operation are different test setups, not like-for-like current measurements.
Table
Parameter
BME280
BME680
What it means for your design
Measurement channels
Humidity, pressure, temperature.
Gas, humidity, pressure, temperature.
Gas sensing is the functional reason to migrate.
VDD operating range
1.71–3.6 V during operation; maximum ripple 50 mV peak-to-peak.
1.71–3.6 V during operation; maximum ripple 50 mV peak-to-peak.
A common regulated rail is possible; revalidate ripple during gas-heater switching.
VDDIO operating range
1.2–3.6 V during operation.
1.2–3.6 V during operation.
Preserve host logic and pull-ups compatible with VDDIO; the swap does not add level translation.
Gas measurement and power path
No gas channel.
Heats a hot plate, holds the target temperature, then measures gas-sensitive-layer resistance.
Budget the actual heater duty cycle and transient supply demand rather than extrapolating environmental-only average current.
Gas output processing
No gas output.
Raw gas resistance is distinct from the IAQ output calculated by BSEC.
Reading gas resistance alone is not the same as implementing an IAQ algorithm.
This compact compatibility map replaces neither part's connection instructions. Bosch's BME280 Figure 16 and BME680 Picture 11 show clockwise numbering in top view and counterclockwise numbering in bottom view; match the marked orientation before comparing pads.
Table
Package contact number
BME280
BME680
1
GND
GND
2
CSB
CSB
3
SDI
SDI
4
SCK
SCK
5
SDO
SDO
6
VDDIO
VDDIO
7
GND
GND
8
VDD
VDD
BME280 pin-order source: Bosch pin-out drawing and table. BME680 pin-order sources: Bosch pin-out drawing and table. Contact numbers are identifiers, not physical measurements.
There is no numbered pin-function difference: the parts are pin-function-compatible, but they are not same-footprint drop-in replacements. The BME280 package drawing gives a nominal 2.50 mm × 2.50 mm body; BME680's nominal body is 3.0 mm × 3.0 mm, with its own top, bottom, and side package drawing in Picture 13. Matching contact names does not establish matching land patterns.
Design differences in a circuit
Retain the logical supply and interface nets only after assigning the replacement's footprint. In their I²C application circuits, both parts recommend 100 nF from each supply to ground and normally use 4.7 kΩ pull-ups, with actual resistance chosen for bus load and interface timing; migration alone does not require changing these nominal passive values. CSB remains tied directly to VDDIO for I²C.
Worked example — engineering calculation, not a sensor-current test: assume a regulated VDD = VDDIO = 3.3 V host design, within both cited operating ranges, and retain the manufacturer-normal 4.7 kΩ pull-ups. For an assumed ideal 0 V low level, each asserted bus line draws I = (3.3 V − 0 V) / 4.7 kΩ = 0.702 mA through its pull-up. This derived current is a bus-load contribution, not either sensor's supply current; it neither includes the BME680 heater nor proves rise-time compliance. Recheck rail transient response and bus timing on the revised board rather than increasing bypass capacitance by guesswork.
Drive levels still follow VDDIO; no higher logic voltage is justified by choosing BME680. The firmware change is substantial: use a BME680-aware driver, read the installed device's compensation parameters, and configure heater duration and target resistance when gas measurement is enabled. The heater setting is device-specific, not simply a temperature written directly as a register code. For IAQ, integrate BSEC's gas-signal processing rather than labeling raw resistance as air quality; BSEC handles humidity compensation, baseline correction, and long-term drift correction.
PCB and layout differences
Footprint: replace the BME280 land pattern with one checked against BME680's package drawing; recheck mask, paste, courtyard, and enclosure fit for the larger body.
Supply routing: engineering guidance is to revalidate the supply and ground paths under the actual heater sequence, not just idle environmental sampling; the gas channel operates a hot plate.
Thermal validation: engineering guidance is to repeat measurements in the final enclosure with the intended gas-heater schedule. Treat heater-enabled operation as a changed thermal condition, not as evidence that the old board's temperature correction remains valid.
Can I replace BME280 with BME680?
Yes, with a PCB and firmware redesign—not by placing BME680 on an unchanged BME280 footprint. The numbered functions match, but the documented package bodies differ.
Change the footprint and revalidate assembly and enclosure geometry.
Keep supply voltages and nominal passives only after checking the actual rail, bus load, and heater operation.
Replace device-specific configuration and compensation code; add heater scheduling and gas processing if used.
Regression-test environmental readings and the intended gas output in the final hardware.
FAQ
Does BME680 add humidity compared with BME280?
No: both parts already measure humidity, pressure, and temperature. BME680 adds a heated gas-resistance measurement channel.
Are BME280 and BME680 pin-compatible?
Their numbered pin functions match in Bosch's pin-out drawings and tables. They are not mechanical drop-ins, so use a replacement-specific footprint rather than approving a swap from the pin names alone.
Does raw BME680 gas resistance equal IAQ?
No: raw gas resistance and BSEC's IAQ output are separate outputs. Use the supported processing path and its compensation and baseline handling when the application calls for IAQ.
Which should I choose for a battery-powered environmental monitor?
Choose BME280 if humidity, pressure, and temperature meet the requirement. Choose BME680 when gas sensing is needed, then evaluate battery life with the intended heater sequence rather than comparing unlike current test setups.