Timer nrf24le1

[Heiko]

Hello,

i am currently trying to integrate a timer properly to my project.

I want to set a pin to high for a duration of 1msec. I configured the timer like shown below:

//********TIMER STUFF**********
TMOD = (TMOD & 0xF0) | 0x20;  /* Set Mode (8-bit timer with reload) */
	
TH1 = 256 - 123;              /* Reload TL1 to count 133 clocks; overflow each ~0.0001 sec! */
TL1 = TH1;
	
ET1 = 1;                      /* Enable Timer 1 Interrupts */
TR1 = 1;                      /* Start Timer 1 Running */

The problem is, that if i choose a duration smaller than 2msec, the pin is always high. If i choose a duration greater than 2msec. Everything works fine.

Is there a maximum time value for swapping a pin from high to low?

Thanks for your help.

[Stian Røed Hafskjold]

In this line:

TMOD = (TMOD & 0xF0) | 0x20;

You mean 0x02 right? In order to set the 8 bit mode with auto reload?

[Heiko]

Hello, in this case it doesn't make any differnce right? 20 -> 100000 and 02 -> 10, but yeah i want to use it in reload mode. Basically i am setting the pin to high and then i count 10 timer interrupts. After 10 interrupts i set the pin to low again. The problem is, the pin is only toggeling between high and low for an interrupt count higher than 18. If i set the toggle time lower, the pin is set to high all the time. Unfortunately i need i toggle time smaller then 10 interrupts (1 millisec), but i am not sure why it reacts like that.

[Heiko]

Hello,

i think i found the cause of this behavior. I am also using hal_nrf for radio transmission, which blocks quite some time so my programm is running quite slowly. I have to find a workaround for that, but it has nothing to do with the timers or some kind of hardware limitation.

[Stian Røed Hafskjold]

Okay! I'm glad you found the cause. Is it okay that I close the thread then?

[Heiko]

Yes it is okay.