Meas_Sensor(); Description; Actions; Prototype - Infineon SP37 Function Manual

2.1

Meas_Sensor()

2.1.1

Description

This function performs a pressure or acceleration sensor measurement determined by SensorConfig.
The pressure or acceleration result can be either:
• Compensated for sensitivity, offset and temperature
• Output as raw value without performing the compensation
The function can measure either pressure or acceleration with up to 64 samples at a specified sample rate. The
function will return the maximum or average (arithmetic mean) pressure or acceleration value in order to
compensate for noise. The function performs a new temperature measurement for compensating the pressure or
acceleration measurements, unless a previously measured raw temperature value is supplied. Number of samples
and raw temperature source are both determined by SensorConfig. SampleRate controls how frequently the
measurement acquisitions occur and will not influence the measurement result under stable input pressure or
acceleration conditions. The device is set to IDLE mode during the delay between measurement acquisitions.
In case of pressure measurement, SensorConfig can be configured to automatically determine the high/low
pressure range where to perform the measurement. The choice of the pressure measurement range can also be
performed manually.The pressure hysteresis thresholds can be selected: either predefined from Infineon factory-
default setting, or specified when calling this function (see SensorResult).
2.1.2

Actions

Pressure Measurement
• Measure pressure sensor with channel and number of samples given by SensorConfig
• Check wire bonds between the ASIC and the sensor die
• Average the measurement result(s), or (optionally) use the maximum raw measurement, to obtain a raw
pressure value
• Sensor gain is automatically configured
• (optionally) Switch between Low and High Pressure range automatically, using configured thresholds
• (optionally) Perform a raw temperature measurement
• (optionally) Compensate the raw pressure value
Acceleration Measurement
• Measure acceleration sensor with channel and number of samples given by SensorConfig
• Check wire bonds between the ASIC and the sensor die & sensor beam integrity
• Sensor gain is automatically configured
• Average the measurement(s), or (optionally) use the maximum raw measurement, to obtain a raw acceleration
value
• (optionally) Perform a raw temperature measurement
• (optionally) Compensate the raw acceleration value
2.1.3

Prototype

unsigned char Meas_Sensor (unsigned int SensorConfig, unsigned char SampRate, signed int idata
*SensorResult )
ROM Library Function Guide
Tire Pressure Monitoring Sensor
22
SP37
ROM Library Functions
Revision 1.0, 2011-12-15