BMP280 Pressure Sensor Symbol
Definition: The BMP280 Pressure Sensor symbol represents a Bosch Sensortec digital barometric pressure and temperature sensor IC used in circuit diagrams as a rectangular module block with VCC, GND, SDA, SCL, and CSB pins, capable of measuring absolute pressure from 300 to 1100 hPa over I²C or SPI interfaces.
Also known as: BMP280, barometric pressure sensor, atmospheric pressure sensor, altitude sensor, BMP280 breakout, pressure and temperature sensor.
What the BMP280 Pressure Sensor symbol means
The BMP280 Pressure Sensor symbol identifies a Bosch Sensortec BMP280 MEMS (Micro-Electro-Mechanical System) sensor IC or breakout module that measures absolute barometric pressure (300–1100 hPa) and ambient temperature (−40 to +85 °C) with high resolution. The sensor communicates with a host microcontroller over I²C (up to 3.4 MHz) or SPI (up to 10 MHz) interfaces. In wiring diagrams the symbol appears as a small rectangle with power and interface pins labelled for connection to an Arduino, ESP32, Raspberry Pi, or other microcontroller.
BMP280 measurements are widely used to calculate altitude above sea level (±1 m resolution under stable conditions), enabling weather monitoring, drone altitude hold, hiking GPS augmentation, and indoor navigation. The symbol guides the designer in planning I²C bus connections, pull-up resistors, and decoupling capacitors for stable operation.
How to identify the BMP280 Pressure Sensor symbol
The BMP280 symbol is drawn as a rectangle labelled 'BMP280' with pins on the left side: VCC (3.3 V supply), GND (ground), SDA (I²C data), and on the right side SCL (I²C clock) and CSB (chip-select bar, tied to VCC for I²C mode or driven by SPI CS). Some breakout board symbols add SDO (I²C address select / SPI MISO) and SDI (SPI MOSI) pins. The compact rectangle reflects the tiny 2.0 × 2.5 mm LGA package of the bare IC.
Function in a circuit
The BMP280 uses a piezoresistive MEMS pressure sensing element and a CMOS analogue front-end to measure absolute pressure with ±1 hPa accuracy (typical) and temperature with ±1 °C accuracy. Built-in digital compensation using factory-calibrated coefficients stored in on-chip OTP memory converts raw ADC readings to calibrated pressure in Pascals and temperature in degrees Celsius. The sensor operates in normal mode (periodic forced measurements at configurable standby intervals) or forced mode (single measurement on command), drawing as little as 2.74 µA in weather-monitoring mode for ultra-low-power IoT applications.
Standards: IEC vs ANSI
| IEC 60617 | IEC 60617 does not define a specific symbol for the BMP280 sensor. In IEC-based diagrams it is represented as a general-purpose rectangular function block per IEC 60617-02, labelled 'BMP280' with I²C/SPI interface pin annotations. |
|---|---|
| ANSI/IEEE 315 | ANSI Y32.2 / IEEE 315 does not define a BMP280-specific symbol. North American circuit diagrams use a labelled rectangular block with pin names following IEEE 315 conventions for integrated circuit packages. |
| Key difference | No IEC 60617 or ANSI Y32.2 glyph uniquely identifies the BMP280; both standards use a labelled rectangle. The part is identified solely by the device name label and pin annotations on the schematic block. |
Terminals / pins
| Pin | Name |
|---|---|
| vcc | VCC |
| gnd | GND |
| sda | SDA |
| scl | SCL |
| csb | CSB |
Typical values
Supply voltage: 1.71–3.6 V (VCC). Supply current: 2.74 µA (weather monitoring mode), 340 µA (normal mode at 1 Hz). Pressure range: 300–1100 hPa. Pressure accuracy: ±1 hPa (typical). Temperature range: −40 to +85 °C. Temperature accuracy: ±1 °C (0–65 °C). I²C addresses: 0x76 (SDO to GND) or 0x77 (SDO to VCC). SPI max clock: 10 MHz.
Where the BMP280 Pressure Sensor symbol is used
- Weather stations and indoor climate monitors measuring barometric pressure trends to forecast weather changes
- Drone and UAV altitude-hold systems using pressure differential to maintain a set altitude above ground or sea level
- GPS trackers and outdoor activity wearables augmenting GPS altitude data with barometric altitude for improved accuracy
- IoT environmental monitoring nodes logging pressure, temperature, and computed altitude over time to cloud dashboards
- Robotics and autonomous vehicles using pressure-derived altitude to support navigation in GPS-denied environments
- Smart-home hub boards (Arduino, ESP32, Raspberry Pi) providing weather data for home automation and display projects
Example
In an ESP32 weather-station schematic, the BMP280 symbol connects VCC to the ESP32 3.3 V rail, GND to common ground, SDA to GPIO21, SCL to GPIO22 (with 4.7 kΩ I²C pull-up resistors on both lines to 3.3 V), and CSB to 3.3 V to select I²C mode. The SDO pin is tied to GND to assign I²C address 0x76. A 100 nF decoupling capacitor is placed between VCC and GND close to the sensor.
Key facts
- The BMP280 measures absolute barometric pressure (300–1100 hPa, ±1 hPa accuracy) and temperature (−40 to +85 °C, ±1 °C accuracy) using a MEMS piezoresistive sensing element.
- Pins are VCC (1.71–3.6 V), GND, SDA (I²C data / SPI SDI), SCL (I²C clock / SPI SCK), CSB (SPI chip select; tie HIGH for I²C), and SDO (I²C address select: LOW = 0x76, HIGH = 0x77).
- The BMP280 supports both I²C (up to 3.4 MHz fast-mode plus) and SPI (up to 10 MHz) interfaces; CSB tied HIGH selects I²C mode.
- Current consumption in ultra-low-power weather-monitoring mode is only 2.74 µA, making the BMP280 suitable for coin-cell-powered IoT devices.
- Altitude can be estimated from pressure using the barometric formula: altitude ≈ 44330 × (1 − (P/P0)^(1/5.255)) metres, where P0 is sea-level reference pressure (1013.25 hPa).
- The BMP280 replaced the older BMP180 with lower power consumption, higher accuracy, and an additional SPI interface option.
- Factory calibration coefficients stored in on-chip OTP memory must be read by firmware to perform compensated pressure and temperature calculations from raw ADC data.
- IEC 60617 and ANSI Y32.2 do not define a dedicated BMP280 symbol; the sensor is represented as a labelled rectangular IC block in all schematic conventions.
Frequently asked questions
What does the BMP280 symbol look like in a circuit diagram?
The BMP280 symbol is a small rectangle labelled 'BMP280' with pins: VCC and GND for power, SDA and SCL for I²C communication (or SDI/SCK for SPI), and CSB for interface-mode selection. The rectangle represents the sensor IC or its breakout module. No unique IEC or ANSI glyph exists; a labelled block is the universal convention.
What does the BMP280 symbol mean in a schematic?
The BMP280 symbol identifies a Bosch Sensortec digital barometric pressure and temperature sensor requiring a 1.71–3.6 V supply and an I²C or SPI connection to a host microcontroller. It signals the designer to include 4.7 kΩ I²C pull-up resistors, a 100 nF decoupling capacitor, and correct CSB/SDO pin strapping for the chosen interface.
What are the pin names on the BMP280 symbol?
The BMP280 pins are VCC (1.71–3.6 V power supply), GND (ground), SDA (I²C data in/out, or SPI SDI), SCL (I²C clock, or SPI SCK), CSB (chip-select bar: HIGH = I²C mode, LOW-active = SPI mode), and SDO (I²C address select: LOW = 0x76, HIGH = 0x77; or SPI SDO output). Some breakout boards also break out an INT interrupt pin.
How do I connect a BMP280 to an Arduino over I²C?
Connect BMP280 VCC to Arduino 3.3 V, GND to GND, SDA to Arduino A4 (SDA), SCL to Arduino A5 (SCL), CSB to 3.3 V (selects I²C), and SDO to GND (I²C address 0x76). Add 4.7 kΩ pull-up resistors from SDA and SCL to 3.3 V. Use the Adafruit BMP280 or Wire library with address 0x76 to read pressure and temperature.
What is the I²C address of the BMP280?
The BMP280 has two selectable I²C addresses: 0x76 when the SDO pin is tied to GND, and 0x77 when SDO is tied to VCC (3.3 V). This allows two BMP280 sensors on the same I²C bus without address conflict. The address is set by the SDO pin strapping visible in the schematic.
How accurate is the BMP280 for altitude measurement?
Under stable atmospheric conditions the BMP280 can resolve altitude changes of approximately ±1 metre. Absolute altitude accuracy depends on knowing the current sea-level reference pressure (P0); a typical error of ±1 hPa in pressure translates to roughly ±8.5 m altitude error. For accurate absolute altitude, the reference pressure must be calibrated against a local weather station or GPS reading.
What is the difference between BMP280 and BMP180?
The BMP280 improves on the BMP180 with lower supply voltage (1.71 V minimum vs 1.8 V), lower current consumption (2.74 µA vs 5 µA in standby), higher pressure resolution (0.18 Pa vs 1 Pa), and the addition of an SPI interface alongside I²C. The BMP280 also adds a humidity-capable sibling, the BME280, which adds a humidity sensor in the same package.
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