CLSID_VIO_MANIFOLD_AIR_PRESSURE

This CLSID returns the absolute air pressure in the intake manifold.

Name

Manifold air pressure

Access

Read, shareable or exclusive

Range

Input

None

Output

Remarks

API device objects expect the following data types and sizes when sending data to and from the mini-drivers:

Mini-driver input

None

Mini-driver output

Example

HRESULT hr;
IVIO_Device *pManifoldPressure;
VARIANT vDeviceData;
USHORT usAbsolutePressure;
const SHORT c_sStdSeaLevelPressure = 101;
SHORT sVacuum;
//Create an instance of the manifold air pressure device and get its 
//IVIO_Device interface.
hr = CoCreateInstance(CLSID_VIO_MANIFOLD_AIR_PRESSURE, NULL,
                     CLSCTX_INPROC_SERVER, IID_VIODEVICE,
                     &pManifoldPressure);
//Ask the device for manifold pressure.
pManifoldPressure->GetData(&vDeviceData, 3000);
//Fetch the air pressure, in kilopascals, from the VARIANT.
usAbsolutePressure = vDeviceData.uiVal;
//Calculate the amount of vacuum from standard atmospheric pressure.
sVacuum = (SHORT) usAbsolutePressure - cStdSeaLevelPressure;
//Release the reference to the interface.
pManifoldPressure->Release();