Pressure 13 Click Board™

How Does The Pressure 13 Click Board™ Work?

The Pressure 13 Click Board™ is based on the KP229E2701, a miniaturized analog absolute pressure sensor based on a capacitive principle from Infineon. The pressure is detected by an array of capacitive surface micromachined sensor cells (a monolithic integrated signal conditioning circuit implemented in BiCMOS technology). The sensor cell output is amplified, temperature compensated, and linearized to obtain an output voltage that is proportional to the applied pressure. The manifold air pressure (MAP) is a principal parameter to compute the air-fuel ratio provided to the engine for lower emission due to better combustion and increased efficiency. For cost-sensitive engine systems, a MAP sensor shows the potential to complement or even substitute mass airflow (MAF) sensors.

The accuracy of the KP229E2701 sensor is influenced by the supply voltage (ratiometric error) as well as by pressure, temperature, and aging effects. All parameters needed for the complete calibration algorithm - such as offset, gain, temperature coefficients of offset and gain, and linearization parameters - are determined after the assembly. These parameters are stored in an integrated E²PROM protected with forwarding error correction (a one-bit error is detected and corrected, errors of more than one bit are detected, and the output signal is switched to ground potential).

In automotive applications where high production volumes are custom, there is substantial interest in precision, low-cost, and fully integrated sensors. That's why the manifold pressure data can be used to compute diagnostics of leakages and malfunctions of the exhaust gas recirculation valve.

The Pressure 13 Click Board™ communicates with MCU using only one GPIO pin routed on the AN pin of the mikroBUS™ socket. The KP229E2701 sensor possesses several digital pins used only during calibration and test. That's why it's recommended and done to leave these pins floating. The output circuit acts as a low-pass decoupling filter between the sensor output and the A/D input of the MCU because it's recommended to protect the pressure sensor against overload and electromagnetic interferences.

The Pressure 13 Click Board™ is designed to be operated only with a 5V logic voltage level. A proper logic voltage level conversion should be performed before the Click board™ is used with MCUs with different logic levels. However, the Click board™ comes equipped with a library that contains easy to use functions and an example code that can be used as a reference for further development.

SPECIFICATIONS

PINOUT DIAGRAM

This table shows how the pinout on Pressure 13 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

ONBOARD SETTINGS AND INDICATORS

PRESSURE 13 CLICK ELECTRICAL SPECIFICATIONS