CC2538: GPTimer compare mode

Hello Kalin,

You should be able to configure the Pxx_SEL fields in the IOC_Pxx_SEL register to assign the timer signals to the appropriate pins.  Please refer to the Technical Reference Manual and Peripheral Driver Library User's Guide for details.  What software are you using, TIMAC, Z-Stack, Foundation Firmware, or otherwise?

Regards,
Ryan

Hi Ryan,

Thanks for reply!

I also think that I should be able but I couldn't. 

I'm using GPT1 and GPT2 in split pair/one shot mode and I did configure the PC0_SEL, PC1_SEL, PC2_SEL, PC3_SEL with corresponding values i.e. IOC_MUX_OUT_SEL_GPT1_ICP1, IOC_MUX_OUT_SEL_GPT1_ICP2, IOC_MUX_OUT_SEL_GPT2_ICP1, IOC_MUX_OUT_SEL_GPT2_ICP2.

The timers are running fine but the pins are not driven.

I already have produced boards with CC2538 and I decided to test google openthread

Best Regards,

Kalin

Please check the other pin configurations in your board file and test with other pins and modes (specifically PWM) to verify that the pins are operable and rule out pinmux issues.

Regards,
Ryan

I did this already, in PWM mode it works

Best Regards

Kalin

Upon further reflection of the documents, this is because the I/O multiplexer only has access to the eight capture/compare PWM pins (CCP).  Therefore your solution must utilize one-shot with interrupts or PWM.

Regards,
Ryan

thanks Ryan
is it possible to setup PWM for a just single pulse 

Best Regards,

Kalin

This is possible in other MCUs, but with the CC2538 in PWM Timing mode the timer continues running after the PWM signal has been generated. The PWM period can be adjusted at any time by writing the GPTMTnILR register, and the change takes effect at the next cycle after the write.  . If PWM interrupts are used, configure the interrupt condition in the TnEVENT field in the GPTIMER_CTL register and enable the interrupts by setting the TnPWMIE bit in the GPTIMER_TnMR register.

Regards,
Ryan