Timmer TM4C129

Hello Oscar,

Considering the scenario, what you are looking for is the timer to count in one-shot mode, and generate an interrupt. In the Interrupt handler you can switch on a LED by setting the GPIO.

1. Look at the example code in timer for one-shot mode for understanding configuration of the timer
2. Look at the blinky example to understand how to configure a GPIO to control a LED

Regards
Amit

Excuse me!! Where can I fine these examples???

Hello Oscar

That would be in TivaWare. Please make sure that you download the full installer.

Regards
Amit

Excuse me, I am working with a camera VGA, I send to it a coomand if the camera no response in 200ms, I need reset the camera.
How can count 250ms with the timmer..

Hello Oscar,

You can start a timer in one shot mode with interrupt with the count set for 250ms once a command is sent. If the response of the command comes before the timer interrupt, disable the timer and reset its count value. If not, the interrupt can be used to set a flag for reset in the main application.

You may refer to the following example code on configuring a timer in 1shot mode. Note that it can be done in 32 bit mode as well.

D:\ti\TivaWare_C_Series-2.1.1.71\examples\peripherals\timer\oneshot_16bit.c

Regards
Amit

Hi Amit..
Excuse me, I have a question..
In the example code timer in one-shot, it is configure to work a 1ms..

//
// Set the Timer0B load value to 1ms.
//
TimerLoadSet(TIMER0_BASE, TIMER_B, SysCtlClockGet() / 1000);

If I work a 250ms???? How can I do?? maybe...

TimerLoadSet(TIMER0_BASE, TIMER_B, SysCtlClockGet() / 250 000);

Hello Oscar,

The value to be loaded will allow for a count value equivalent to the time. So if you load a value of SysCtlClockGet it will count for 1 sec as it is going to count SysCtlClockGet worth of clocks at SysCtlClockGet frequency value. I hope that explains how to get 250ms.

Regards
Amit

Excusme.. Do you speak spanish?
Idon't understeand you..

Hello Oscar,

First of all I do not speak spanish.

Secondly, since this is TM4C129 device (and I should have noted the same), the function SysCtlClockGet is not a valid function for this device family. The System Clock Frequency is the return value of the function SysCtlClockFreqSet.

Thirdly, let us assume that System Clock Frequency is 120MHz (120 000 000). Now if you load the value of 1000, it would mean that the time taken for counting 1000 would be 1000/(120 000 000) = 8.3us. Now if you need to count for 250ms, the count value must be 250e-3*120e6 = 30 000 000.

Regards
Amit

THANKE YOU for you help me, I new in this topic... I am really really zorry....

Hello Oscar

No problem. Reading the section of data sheet and register programming model with aid a lot on top of the forum.

Regards
Amit

Where can I find an example for how configure el timer One-sot 32 bits...

thanke you so much, I did what you told me!! and it worked....

Hello Oscar

Do post a link to the code or the forum post that helped. It may be useful for the next forum user :-)

Regards
Amit