DPS310 barometric pressure sensor

The Infineon DPS310 reads air pressure to a fraction of a pascal, and temperature, over I2C at 0x77 or 0x76.

Aliases: Adafruit DPS310, Grove DPS310, barometer, altimeter. Precise enough to tell a table from the floor by altitude, it is the pressure sensor of drones and step counters.

Pins

Pin	What it does
VIN	Supply, 3 to 5 V on the board.
GND	Ground.
SCL, SDA	I2C. The board carries the pull-ups.

Properties

address is 0x77 or 0x76. pressure (hPa, 300 to 1200) and temperature are the weather; the two sliders change them while the circuit runs.

Reading it on an Arduino

With Adafruit's library, which Mokxi ships as Adafruit_DPS310.h:

#include <Adafruit_DPS310.h>
Adafruit_DPS310 dps;

void setup() {
  Serial.begin(9600);
  if (!dps.begin_I2C()) Serial.println("No DPS310");
  dps.configurePressure(DPS310_64HZ, DPS310_64SAMPLES);
  dps.configureTemperature(DPS310_64HZ, DPS310_64SAMPLES);
}

void loop() {
  sensors_event_t temp, pressure;
  if (dps.temperatureAvailable() && dps.pressureAvailable()) {
    dps.getEvents(&temp, &pressure);
    Serial.println(pressure.pressure);
  }
}

How it talks

• The product ID at 0x0D reads 0x10. After power on and a soft reset (0x09 to 0x0C) SENSOR_RDY comes up in 12 ms and COEF_RDY in 40 ms.
• MEAS_CFG (0x08) runs one pressure or temperature reading, or both continuously at the rates in PRS_CFG and TMP_CFG. A reading takes 3.6 ms at once up to 206.8 ms at 128 times oversampling; then PRS_RDY or TMP_RDY is set, and reading the result clears it.
• The results are raw 24-bit counts. The library turns them into pascals and degrees with the coefficients at 0x10 to 0x21 and the oversampling's scale factor.

What it does not model

The FIFO and the interrupt pin, and the noise oversampling removes.

Common mistakes

Reading before COEF_RDY: the coefficients are not loaded for the first 40 ms. Expecting a new reading every loop: at 64 times oversampling each one takes 104 ms.