The CYW954907AEVAL1F EVK enables customers to evaluate and develop single-chip Wi-Fi applications using CYW54907 devices. The CYW954907AEVAL1F EVK uses WICED Studio IDE to develop and debug your CYW54907 projects. In this code example, I have interfaced Infineon's precision pressure sensor DPS310 to the 54907 evaluation board and measured the temperature and pressure values of the surroundings via I2C. The required pins of the sensor are --> VDD(Supply Voltage 3.3V for analog blocks), VDDIO (Digital Supply Voltage 3.3V for digital blocks and I/O interface), GND, SDI and SCK. The application is implemented in WICED STUDIO IDE. The provided code example for DPS310 can be used for various IOT applications such as indoor navigation, health and sports, outdoor navigation, weather station etc.
Let's get started with the sensor's introduction!
The Infineon's DPS310 is a miniaturized Digital Barometric Air Pressure Sensor with a high accuracy and a low current consumption, capable of measuring both pressure and temperature. The pressure sensor element is based on a capacitive sensing principle which guarantees high precision during temperature changes. The small package makes the DPS310 ideal for mobile applications and wearable devices.
The internal signal processor converts the output from the pressure and temperature sensor elements to 24 bit results. Each unit is individually calibrated, the calibration coefficients calculated during this process are stored in the calibration registers. The coefficients are used in the application to convert the measurement results to high accuracy pressure and temperature values. The result FIFO can store up to 32 measurement results, allowing for a reduced host processor polling rate. Sensor measurements and calibration coefficients are available through the serial I2C or SPI interface. The measurement status is indicated by status bits or interrupts on the SDO pin.
For more features information and typical applications, refer to the DPS310 datasheet attached.
Temperature and Pressure Measurement
Calculation of Compensated Values
1. Read the pressure calibration coefficients (c00, c10, c20, c30, c01, c11, and c21) from the Calibration Coefficient register. Note: The coefficients read from the coefficient register are 2's complement numbers.
2. Choose scaling factors kT (for temperature) and kP (for pressure) based on the chosen precision rate. The scaling factors are listed in datasheet.
3. Read the pressure and temperature result from the registers or FIFO. Note: The measurements read from the result registers (or FIFO) are 24 bit 2´s complement numbers. Depending on the chosen measurement rates, the temperature may not have been measured since the last pressure measurement.
4. Calculate scaled measurement results.
5. Calculate compensated measurement results.
There could be a problem with temperature measurement of the DPS310. If your DPS310 indicates a temperature around 60 °C although you expect around room temperature, e.g. 20 °C, you have to update some registers with the specified values as given in the "DPS310_correct_temp_error" function in my code example and this will then provide the correct temperature value. As per Infineon, this can occur because of a fuse bit issue in some of the sensor's silicon. The function allows us to work around the issue.
For more information on this, please visit this link --> https://www.infineon.com/cms/en/product/sensor/pressure-sensors/pressure-sensors-for-iot/dps310/