MSPM0C1104: Add TIMER-PWM in my project but not working

Hi,

Could you please share the sysconfig file and code? It can accelerate to find the cause.

Regards,

Zoey

Because the project is belong to my company, it's hard to share to you.

I want to control a PWM fan with different speed on different stages, and I already read the example here.

https://dev.ti.com/tirex4-desktop/content/mspm0_academy_2_01_01_00/_build_mspm0_academy_2_01_01_00/source/msp_m0/msp_m0_timer_pwm_training/msp_m0_timer_pwm_training.html

I'm trying this example on an EVM and have the PWM fans running at different speeds (seems to work), but I don't know how to add PWM fan control to my project.

Maybe you can give me the steps to add PWM fan control functionality in a new project.

Thank you.

Hi Cecilia,

I am not sure the fan is related to what attribute of PWM.

For changing the feature of PWM, you can change the frequency and duty cycle in sysconfig:

The step of adding PWM in your self project, you can add TIMER-PWM in your sysconfig file, and change the paraments following the code example.

Regards,

Zoey

I changed duty cycle, but it doesn't work. 
Then I changed the .syscfg of the pwm_edge_sleep example (see the attached .tar) and flashed it to our customized board.

timx_timer_mode_pwm_edge_sleep_LP_MSPM0C1104_nortos_gcc.tar

But nothing happened.......

The MCU we used is like this one

and here is our design for PWM fan (4 wire)

I tried these two settings for PWM, but both failed. 

[Default]

[According our design]

What should I do?

Hi,

Have you developed it based on Launchpad before?

I just want to make sure whether the reason is cased by hardware.

If you use the demo code in SDK, it seems the software is ok and PWM can be outputted normally.

Regards,

Zoey

Have you developed it based on Launchpad before?
> Never.

I just want to make sure whether the reason is cased by hardware.

> I can't tell whether the hardware is normal or not

Now, I try to run the basic example 'Out of Box' on EVM, but I got this error.

 

I connect the EVM with USB cable and the settings of EVM is like this

Maybe I should run this example normally before starting running PWM example. (sad)

Hi,

No, you do not need to use out_of_box code example. Please import ...\ti\mspm0_sdk_2_03_00_07\examples\nortos\LP_MSPM0C1104\driverlib\timx_timer_mode_pwm_edge_sleep to your project and download it to your self hardware to see if it can output PWM.

And by the way, could you please share you schematic of your own board?

Regards,

Zoey

Is it ok to download pwm_edge_sleep from 'Create New Project' ?



And I only change the MCU layout to WQFN-20(RUK) 

Then, here are the schematic of our board

MCU

PD (connect to FAN_PWM and FAN_TACH)

pin table from HW RD

Regards,
Cecilia

Yes,it is ok. But for the green hand, we recommend to download our SDK and import it directly. It can avoid to set up environment.

Please have a try in this way. Hopefully it can save you time and succeed to output PWM.

Regards,

Zoey

So after downloading the code example, you can not see any PWM in the MCU right?

How do I know for sure?

Could you please connect oscillograph to check whether GPIO is toggled?

I have no oscillograph on hand. Is there any other way to know for sure ?

You can use the digital multimeter to test the average voltage for this pins

Thank you for your help.

After discussing with HW RD and changing the layout of HW, now I can set the PWM duty cycle to control the speed of fan.
But I want to know the current speed of fan by reading the FAN_TACH pin (connect to PA2).
Here is my settings and codes.

I try to read the value of FAN_Tach as below,

fanTach = DL_GPIO_readPins(GPIO_TACH_PORT, GPIO_TACH_PIN_1_PIN);

But regardless of the duty cycle, the value of fanTach is always 0x04.

How to correctly read the FAN_TACH (PA2) value?

Hi,
I don't recommend you using delay in GPIOA interrupt.
You need to take GPIOA interrupt trigger frequency in consideration.
Normally, GPIOA as a fan speed feedback input, interrupt frequency is around 50 ~ 5kHz.
And you add a 5s delay in Interrupt, this will cause interrupt word abnormally.
GPIOA interrupt should update the pin status, and you need add frequency process in main while.
Regards,
Zoey

Ok, I see. 
The code written in GPIOA_IRQHandler is just test code to identify if the IRQ has been triggered and if the fan speed can be changed.

Now I know the fan speed (rpm) is calculate by the pulses per second from TACH pin (PA2).
Could you give me an example for counting pulses per second?


And I also want to change the Fan speed based on the value of thermal sensor.
Could you give me some examples for that too?

Thank you.

You can change the duty cycle of PWM to change the fan speed.

Currently, we do not have this code example.

It should be written by customer self.