Other Parts Discussed in Thread: SYSBIOS
We are working on a Sensor driver for J7 using the TI-RTOS Imaging SDK component.
Currently we have a sensor driver working for our target camera, but we are adding a feature to enable and control an external train pulse signal which will allow the camera to stream in slave mode. Basically we would like to enable a periodic function to constantly switch from HIGH to LOW using a specific duty cycle and we want to collect the timestamps for every positive level switch.
For that we want to use a Timers API to enable and configure the period for a GPIO signal which will be reached by the camera.
I did some research on the documentation about it, but I couldn't find good information about how to use Timers on TI-RTOS, so I was analyzing files on the SDK and I found some interesting APIs.
- crete-j7-rtos/bios_6_82_01_19/packages/ti/sysbios/knl/Clock.c
- crete-j7-rtos/bios_6_82_01_19/packages/ti/posix/tirtos/timer.c
- crete-j7-rtos/pdk_jacinto_07_00_00/packages/ti/osal/src/tirtos/TimerP_tirtos.c
I found an example which uses the "TimerP" API:
- crete-j7-rtos/pdk_jacinto_07_00_00/packages/ti/diag/sdr/test/sdtf-test/src/sdtf_main.c
I did a quick implementation, adding code to the sensor driver trying to print a message every 1 ms. However, I didn't see the message being printed. I attached the code here:
...
TimerP_Params periodicTimerParams;
TimerP_Handle periodicTimerHandle;
/* TimerP_Status timerStatus; */
appLogPrintf("*************** PROBE ***************** \n");
/* Initialize timer parameters */
TimerP_Params_init(&periodicTimerParams);
/* Configure periodic timer for 1 ms*/
periodicTimerParams.period = 1000; /* 1 ms */
periodicTimerParams.periodType = TimerP_PeriodType_MICROSECS;
periodicTimerParams.arg = &periodicTimerHandle;
periodicTimerParams.startMode = TimerP_StartMode_USER;
periodicTimerParams.startMode = TimerP_StartMode_AUTO;
periodicTimerParams.runMode = TimerP_RunMode_CONTINUOUS;
/* Create Periodic Timer */
appLogPrintf("*************** PROBE: Create Timer ***************** \n");
periodicTimerHandle = TimerP_create(
TIMER_ID,
(TimerP_Fxn)&GW5300_PeriodicTests,
&periodicTimerParams);
if (periodicTimerHandle == NULL) {
appLogPrintf("ERR: Timer create failed\n");
return -1;
}
/* Start the Timer */
appLogPrintf("*************** PROBE: Start Timer ***************** \n");
timerStatus = TimerP_start(periodicTimerHandle);
if (timerStatus != TimerP_OK) {
appLogPrintf("ERR: Could not start the timer %d \n", TIMER_ID);
return -1;
}
appLogWaitMsecs(1000);
/* Stop the Timer */
appLogPrintf("*************** PROBE: Stop Timer ***************** \n");
timerStatus = TimerP_stop(periodicTimerHandle);
if (timerStatus != TimerP_OK) {
appLogPrintf("ERR: Could not stop the timer %d \n", TIMER_ID);
return -1;
}
/* Delete the Timer */
appLogPrintf("*************** PROBE: Delete Timer ***************** \n");
timerStatus = TimerP_delete(periodicTimerHandle);
if (timerStatus != TimerP_OK) {
appLogPrintf("ERR: Could not delete the timer %d \n", TIMER_ID);
return -1;
}
appLogPrintf("*************** PROBE END ***************** \n");
...
I have some questions:
- Do you have information about Timer APIs that you can share or tell me where to find it?
- What is the best way to implement Timers? Do you have examples?
- How can I compile and run the example found on the SDK?
- What do you think about my test? Is there something missing? Should I use a different API?
Thanks.
-Enrique
