Hardware Utilities API

The Hardware Utilities API encompasses the needed software to control and monitor certain functionalities on the ARCS motion control board which are needed for realtime control, such as interrupt initialization and handling.

Example Use

In the following example, an Interrupt Service Routine is created, which computes the control signal per sampling interval.
float testValue0 = 0.0;
float pi = 3.1415926;
float Nperiod = 1000.0;
float A = 1.0;
float k = 0.0;
float DT0 = 0.001;
float DT1 = 0.01;
float execTime;
int flag = 0;
/* main program for control applications */
#pragma INTERRUPT (timer0)
void timer0 ()
{
volatile unsigned int i;
startIsrExecTime (0);
if (flag)
setDioWord (0, 0xaaaa);
else
setDioWord (0, 0x5555);
flag = flag == 0 ? 1 : 0;
if (k>Nperiod)
k=0.0;
testValue0 = A* sin((2.0*pi*k)/Nperiod);
k = k+1.0;
setActuator ( 0, testValue0 ));
k = k+1.0;
setActuator ( 0, testValue0 );

execTime = finishIsrExecTime (0);

}
#pragma INTERRUPT (timer1)
void timer1 ()
{
volatile unsigned int i;
startIsrExecTime (0);
if (flag)
setDioWord (1, 0xaaaa);
else
setDioWord (1, 0x5555);
flag = flag == 0 ? 1 : 0;
execTime = finishIsrExecTime (0);
}
main()
{
unsigned int ii;
unsigned int numDacChannels;
unsigned int numDioChannels = 2;
dspInit (8, 8, 2, 0, 0, 2);
numDacChannels = getNumDacs();
for (ls = getNumDacs();
for (ii=0;ii<numDacChannels;ii++)
{
initDac (ii, 1, 0, 12, 10.0);
initAct (ii,-10.0,-10.0,10.0,10.0);
}
setDioWordConfig (0,0xffff);
setDioWordConfig (1,0xffff);
initIsr (0, ISR_TIMER0, &timer0, NO_ISR, 0x0000);
initIsr (1, ISR_TIMER1, &timer1, NO_ISR, 0x0000);
setSamplingPeriod( 0, DT0);
enableIsr (0);
setSamplingPeriod( 1, DT1);
enableIsr (1);
while(1)
communications();
}

Method Index

o hdwInit()
o clearErrors()
o checkError()
o setNumIsrs ()
o getNumIsrs ()
o initIsr()
o initTimerIsr() initTimerIsr()
o enableIsr()
o disableIsr()
o startIsrExecTime()
o finishIsrExecTime()
o setSamplingPeriod()
o getSamplingPeriod()
o checkOverTime()

Methods

hdwInit 
void hdwInit( unsigned int numOfEncoders, unsigned int numOfDACs,
unsigned int numOfDIOs, unsigned int numOfADCs, unsigned int
numOfPWMs, unsigned int numOfSTEPPERs, unsigned int numOfISRs 
);
Initializes the hardware configuration.
Parameters:
numOfEncoders: number of encoder channels
numOfDACs: number of actuator (D/A) channelsumber of actuator (D/A) channels
numOfDIOs: number of dscrete (digital) inputs/outputs
numOfADCs: number of analog sensor (A/D) channels
numOfPWMs: number of pulse width modulated outputs
numOfSTEPPERs: number of stepper motor channels
numOfISRs: number of Interrupt Service Routines; currently the ARCS system supports only two hardware interrupts, 0 and 1.
clearErrors 
void clearErrors();
Clears all errors.
checkError 
unsigned int checkError();
Returns
the integer value associated with the error.
setNumIsrs 
void setNumIsrs (unsigned int noChannels);
Sets the number of interrupts.
Parameters:
noChannels: sets number of interrupts- currently only 2 are supported.
getNumIsrs 
unsigned int getNumIsrs ();
Returns
The total number of Interrupt Service Routines
initIsr 
void initIsr(unsigned int isrChannel, unsigned int isrLevel, void
(*isrHander)(), unsigned int trapLevel, void (*trapHander)());
Initializes the interrupt handlers, generally to perform specific realtime calculations.
Parameters
isrChannel: interrupt number, 0 or 1.
isrLevel: Interrupt level; ISR_TIMER0 or ISR_TIMER1. ISR_TIMER0 has higher priority.
*isrHandler: pointer to interrupt routine function, e.g. to controlLoop() in example.
trapLevel:
*trapHandler: pointer to routine for handling errors.
initTimerIsr 
void initTimerIsr(unsigned int isrChannel, unsigned int isrLevel, void
(*isrCalledFunc)(), unsigned int trapLevel, void (*trapHander)());
Initializes timer based ISR
enableIsr 
void enableIsr(unsigned int Channel);
Enables interrupts.
Parameters Channel: interrupt number (0 or 1 in current hardware configuration).
disableIsr 
void disableIsr(unsigned int Channel);
Disables interrupts.
Parameters ables interrupts.
Parameters
Channel: interrupt number
startIsrExec 
void startIsrExecTime(unsigned int isrChannel);
Starts the clock to time to determine the total time taken for the execution of then of the interrupt service routine.
Parameters:
isrChannel: interrupt number
finishIsrExecTime 
float finishIsrExecTime(unsigned int isrChannel);
Determines the time taken for the end of the interrupt service routine.
Parameters
isrChannel: interrupt number (0 or 1).
Returns
Total time for executio of the interrupt service routine.
setSamplingPeriod 
void setSamplingPeriod(unsigned int isrChannel, float T);
Sets the sampling period for the specific interrupt.
Parameters
isrChannel: interrupt service number (0 or 1).
T: sampling period in seconds.
getSamplingPeriod 
float getSamplingPeriod(unsigned int isrChannel);
Provides the sampling period for the specific interrupt routine.
Parameters
isrChannel: interrupt number
Returns
sampling interval for the specific interrupt number.
checkOverTime 
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checkOverTime 
unsigned int checkOverTime();

 
Check if any of the ISR over time flags has been set.


Return


 0: No over time 

 
 1: Over time flag has been set






Last modified: Mon Feb 15 00:02:37 Eastern Standard
Time 1999


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