EK-LM3S8962 (Luminary micro) access to QEI

[dmoradi]

Hi,

I got the evaluation board for the NI embedded ARM and I am trying to understand its capabilities. I used to use Atemel AVR and PICs microcontrollers to design my controlers using C programming language. I have done a couple of projects with LabView and it will be a great improvement for me if I can program the microcontrollers with LabView. So far I have done simple testing with my evaluation board and it looks great. But I couldn't access some of the resources on the controller, for example:.

• LM3S8962 (Luminary micro) has two QEI (quadrature Encoder Interface) but I dont know how to read them or how to configure them to use.
• HOw to configur the external interrupt, I found the timer interrupts but couldn't find any thing about other interrupts.

I appreciate your help

Davood

[Gmg]

• LM3S8962 (Luminary micro) has two QEI (quadrature Encoder Interface) but I dont know how to read them or how to configure them to use.

Unfortunately, there is no support for QEI as of the LabVIEW 2009 release.  Expect this in the next release.  It is still possible to interact with the QEI peripheral, but it requires a driver-level understanding.  There is a luminary driver library, StellarisWare, which can be used to interact with QEI.  This library is already linked into your LabVIEW project, so you would just need to use inline C nodes to call the proper QEI functions.

 

void	QEIEnable (unsigned long ulBase)
void	QEIDisable (unsigned long ulBase)
void	QEIConfigure (unsigned long ulBase, unsigned long ulConfig, unsigned long ulMaxPosition)
unsigned long	QEIPositionGet (unsigned long ulBase)
void	QEIPositionSet (unsigned long ulBase, unsigned long ulPosition)
long	QEIDirectionGet (unsigned long ulBase)
tBoolean	QEIErrorGet (unsigned long ulBase)
void	QEIVelocityEnable (unsigned long ulBase)
void	QEIVelocityDisable (unsigned long ulBase)
void	QEIVelocityConfigure (unsigned long ulBase, unsigned long ulPreDiv, unsigned long ulPeriod)
unsigned long	QEIVelocityGet (unsigned long ulBase)

 

•  How to configure the external interrupt, I found the timer interrupts but couldn't find any thing about other interrupts.

These interrupts are configured much the same way as the timer interrupts.  The interrupt will fire when a rising/falling edge is detected on the corresponding pin.  I looked at the user manual for the MCB2300 (which I assume you are using here) and found the following map:

• EINT0 = pin 76
• EINT1 = pin 75
• EINT2 = pin 73
• EINT3 = pin 71

[dmoradi]

i started to use the inline C node to make the QEI work, but i stocked on the first step, 

what is the ulBase address?

I couldnt find anything about it.

thanks

Davood

[Kevin_S]

Davood,

You're welcome to query the community here regarding the implementation of QEI functionality.  Just know that you might get a faster (and more detailed) response if you post to the forums of Luminary Micro/TI (for the LM3S8962 eval board) or Keil (for the MCB2300 eval board).

Luminary Micro Support Forums

Keil Discussion Forums

Kevin S.

Applications Engineer

National Instruments