vpComedi Class Reference

#include <visp3/sensor/vpComedi.h>

Inheritance diagram for vpComedi:

Public Member Functions
	vpComedi ()
virtual	~vpComedi ()

Protected Attributes
Protected Member Functions Inherited from vpComedi
std::string	m_device
comedi_t *	m_handler
unsigned int	m_subdevice
unsigned int	m_range
unsigned int	m_aref
unsigned int	m_nchannel
std::vector< comedi_range * >	m_range_info
std::vector< lsampl_t >	m_maxdata
std::vector< unsigned int >	m_chanlist

Inherited functionalities from vpComedi
void	close ()
comedi_t *	getHandler () const
std::vector< lsampl_t >	getMaxData () const
unsigned int	getNChannel () const
vpColVector	getPhyData () const
std::string	getPhyDataUnits () const
std::vector< comedi_range * >	getRangeInfo () const
unsigned int	getSubDevice () const
void	open ()
void	setAnalogReference (const unsigned int &aref)
void	setChannelNumbers (const unsigned int &nchannel)
void	setDevice (const std::string &device)
void	setRange (const unsigned int &range)
void	setSubDevice (const unsigned int &subdevice)
std::vector< lsampl_t >	getRawData () const

Detailed Description

Interface for data acquisition devices supported by Comedi. Comedi is a linux control and measurement device interface. For more information see http://www.comedi.org.

This class was tested with ATI Gamma 65-SI FT sensor connected to a National Instrument NI DAQmx PCI-6220 board.

Warning

If you experience an exception like

Could not open device /dev/comedi0

you may set up udev permissions for Comedi device files. Once Comedi is installed you also need to make sure that the user has appropriate permissions for accessing the Comedi device files. That is you need to be able to have read and write access to the /dev/comedi* files. One elegant way to achieve this to create a new group and tell udev to add the Comedi device files to this group. To this end:

1. Login as root
2. Create a new group "iocard":

   $ addgroup --system iocard

3. Add udev rules to the /etc/udev/rules.d directory:

   $ echo 'KERNEL=="comedi*", MODE="0660", GROUP="iocard"' > /etc/udev/rules.d/95-comedi.rules

4. Add users to the "iocard" group:

   $ adduser <username> iocard

5. Reboot

The following example shows how to run an synchronous data acquisition at 500 Hz, calling getPhyData() each 2 ms:

#include <visp3/sensor/vpComedi.h>
 
#ifdef ENABLE_VISP_NAMESPACE
using namespace VISP_NAMESPACE_NAME;
#endif
 
int main()
{
  vpComedi comedi;
  comedi.setDevice("/dev/comedi0");
  comedi.setChannelNumbers(6); // to read a F/T tensor
  comedi.open();
 
  for(unsigned int i=0; i < 500; i++) {
    std::cout << "Physical data (in " << comedi.getPhyDataUnits() << "): " << comedi.getPhyData().t() << std::endl;
    vpTime::wait(2);
  }
  comedi.close();
}

Examples

testComedi.cpp.

Definition at line 111 of file vpComedi.h.

Constructor & Destructor Documentation

vpComedi()

BEGIN_VISP_NAMESPACE vpComedi::vpComedi

(

)

Default constructor.

Definition at line 49 of file vpComedi.cpp.

~vpComedi()

vpComedi::~vpComedi ( )

virtual

Destructor that closes the connection to the device if it is not already done calling close().

See also

close()

Definition at line 58 of file vpComedi.cpp.

References close().

Member Function Documentation

close()

void vpComedi::close

(

)

Close the connection to the device.

Definition at line 90 of file vpComedi.cpp.

References m_handler.

Referenced by vpForceTorqueAtiSensor::close(), and ~vpComedi().

getHandler()

comedi_t* vpComedi::getHandler ( ) const

inline

Get native Comedi handler.

Definition at line 121 of file vpComedi.h.

getMaxData()

std::vector<lsampl_t> vpComedi::getMaxData ( ) const

inline

Get max data per channel. The returned vector is of dimension the number of channels.

Definition at line 124 of file vpComedi.h.

getNChannel()

unsigned int vpComedi::getNChannel ( ) const

inline

Get number of channels.

Examples

testComedi.cpp.

Definition at line 126 of file vpComedi.h.

getPhyData()

vpColVector vpComedi::getPhyData

(

)

const

Get physical data from device with units in Volts or mA. To know which unit is used, call getPhyDataUnits().

Examples

testComedi.cpp.

Definition at line 133 of file vpComedi.cpp.

References vpException::fatalError, getRawData(), vpMath::isNaN(), m_handler, m_maxdata, m_nchannel, and m_range_info.

Referenced by vpForceTorqueAtiSensor::bias(), vpForceTorqueAtiSensor::getForceTorque(), and vpForceTorqueAtiSensor::unbias().

getPhyDataUnits()

std::string vpComedi::getPhyDataUnits

(

)

const

Get units (V or mA) of the physical data acquired by getPhyData() or getPhyDataAsync().

Examples

testComedi.cpp.

Definition at line 155 of file vpComedi.cpp.

References vpException::fatalError, m_handler, and m_range_info.

getRangeInfo()

std::vector<comedi_range *> vpComedi::getRangeInfo ( ) const

inline

Get data range information per channel. The returned vector is of dimension the number of channels.

Definition at line 133 of file vpComedi.h.

getRawData()

std::vector< lsampl_t > vpComedi::getRawData ( ) const

protected

Get raw data from device. If you selected an analog input subdevice, the output is an unsigned number, for example between 0 and 65535 for a 16 bit analog input, with 0 representing the lowest voltage of the ADC, and a hardware-dependent maximum value representing the highest voltage.

Definition at line 105 of file vpComedi.cpp.

References vpException::fatalError, m_aref, m_device, m_handler, m_nchannel, m_range, and m_subdevice.

Referenced by getPhyData().

getSubDevice()

unsigned int vpComedi::getSubDevice ( ) const

inline

Get comedi subdevice.

Definition at line 135 of file vpComedi.h.

open()

void vpComedi::open

(

)

Open the connection to the device.

Examples

testComedi.cpp.

Definition at line 63 of file vpComedi.cpp.

References vpException::fatalError, m_aref, m_chanlist, m_device, m_handler, m_maxdata, m_nchannel, m_range, m_range_info, and m_subdevice.

Referenced by vpForceTorqueAtiSensor::open().

setAnalogReference()

void vpComedi::setAnalogReference ( const unsigned int &  aref )

inline

Set analog reference type.

Parameters

aref	: The aref parameter specifies an analog reference to use: AREF_GROUND, AREF_COMMON, AREF_DIFF, or AREF_OTHER.

Definition at line 144 of file vpComedi.h.

setChannelNumbers()

void vpComedi::setChannelNumbers ( const unsigned int &  nchannel )

inline

Number of channels to read from sensor. For a 6-dim force/torque sensor use 6.

Examples

testComedi.cpp.

Definition at line 150 of file vpComedi.h.

Referenced by vpForceTorqueAtiSensor::open().

setDevice()

void vpComedi::setDevice ( const std::string &  device )

inline

Set comedi device name. Default value is /dev/comedi0.

Examples

testComedi.cpp.

Definition at line 153 of file vpComedi.h.

setRange()

void vpComedi::setRange ( const unsigned int &  range )

inline

Set the range parameter that is the zero-based index of one of the gain ranges supported by the channel. This is a number from 0 to N-1 where N is the number of ranges supported by the channel.

Definition at line 160 of file vpComedi.h.

setSubDevice()

void vpComedi::setSubDevice ( const unsigned int &  subdevice )

inline

Set comedi analog input subdevice.

Definition at line 162 of file vpComedi.h.

Member Data Documentation

m_aref

unsigned int vpComedi::m_aref

protected

Analog reference

Definition at line 175 of file vpComedi.h.

Referenced by getRawData(), and open().

m_chanlist

std::vector<unsigned int> vpComedi::m_chanlist

protected

Channel list

Definition at line 179 of file vpComedi.h.

Referenced by open().

m_device

std::string vpComedi::m_device

protected

Comedi device name (default: /dev/comedi0)

Definition at line 171 of file vpComedi.h.

Referenced by getRawData(), and open().

m_handler

comedi_t* vpComedi::m_handler

protected

Comedi handler

Definition at line 172 of file vpComedi.h.

Referenced by close(), getPhyData(), getPhyDataUnits(), getRawData(), and open().

m_maxdata

std::vector<lsampl_t> vpComedi::m_maxdata

protected

Max data value

Definition at line 178 of file vpComedi.h.

Referenced by getPhyData(), and open().

m_nchannel

unsigned int vpComedi::m_nchannel

protected

Number of channels

Definition at line 176 of file vpComedi.h.

Referenced by getPhyData(), getRawData(), and open().

m_range

unsigned int vpComedi::m_range

protected

Range of a channel

Definition at line 174 of file vpComedi.h.

Referenced by getRawData(), and open().

m_range_info

std::vector<comedi_range *> vpComedi::m_range_info

protected

Range information

Definition at line 177 of file vpComedi.h.

Referenced by getPhyData(), getPhyDataUnits(), and open().

m_subdevice

unsigned int vpComedi::m_subdevice

protected

Input subdevice

Definition at line 173 of file vpComedi.h.

Referenced by getRawData(), and open().