Is there an example code for using PWM on the nRF51822 with a SoftDevice?

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Bndit — Tue, 16 May 2017 10:06:46 GMT

This will not compile, there is an error says : undefined reference nrf_gpiote_unconfig

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Petter Myhre — Fri, 19 Sep 2014 09:35:58 GMT

This is not an answer. Vote on the question if it is useful, and thank the ones who answer by voting on their answer.

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

bforutan — Tue, 19 Aug 2014 05:59:29 GMT

I found this very helpful guys. thanks!!

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Patriko — Sun, 03 Aug 2014 12:22:49 GMT

Hi!

There is an issue with flickering when receiving / sending data over BLE. I set priority to 1 and it helped a little bit. I need stable PWM signal with 10 bit resolution and aprox. 250 Hz. Is it possible with this library and reading/writing characteristics at the same time?

Cheers, Patriko

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

krishna — Wed, 02 Jul 2014 11:45:15 GMT

Hi i have a question .

Do we still need to make main file when we are using this simple example which you have uploaded? and also can you please explain what is this done

#if (PWM_NUM_CHANNELS == 1) void nrf_pwm_init(uint32_t io_select_pwm0, nrf_pwm_mode_t pwm_mode) { pwm_io_ch[0] = io_select_pwm0; nrf_gpio_cfg_output(io_select_pwm0); pwm_running[0] = 0;

pwm_init_common();

} what does io_select_pwm0 represents?

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Hyeongho Seo — Mon, 16 Jun 2014 08:19:26 GMT

Hi, It seems like the attached Simple PWM file is not available. Would you please re-upload it? Thanks.

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Maik — Wed, 28 May 2014 09:11:36 GMT

Hello,

I am sorry to write this as an answer but a comment is not pushing the thread. Is the attachment still available?

regards

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Maik — Tue, 27 May 2014 14:34:01 GMT

Hi, thank you for providing this PWM sample - but the attachment does not longer be existend? Could you please double-check if it is still available?

Regards ME_

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

ovrebekk — Thu, 10 Apr 2014 22:37:02 GMT

Hi Andreas

Did you figure this out?

For questions like these I would recommend opening a new thread, otherwise it will quickly get lost. You can always refer to this thread to put your question in context.

To answer your question, make sure you are not updating the CC registers while the timer value is at some random spot between min and max. If you look at the PWM example you can see that the CC registers are only updated while the timer is stopped and the timer value is at the max position.

Best regards Torbjørn

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Andreas Feuersinger — Fri, 14 Feb 2014 12:37:31 GMT

Hi, I have the problem that my custom Timer controlled PWM has the same bug as yours had. I sometimes get inverted PWM output.

Could you point out what was necessary to circumvent this??

I try to update CC values for a timer at runtime by:


void setPw(uint8_t pw) {
    gPulseW = pw;
    uint8_t period = 8 * gPeriod;
    NRF_TIMER0->CC[0] = pw;
    NRF_TIMER0->CC[1] = period/2;
    NRF_TIMER0->CC[2] = period/2+pw;
    NRF_TIMER0->CC[3] = period;
}

I tried to stop and start again, reset EVENTS_COMPARE Register, ... I don't seem to find the bug ...

any help appreciated

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Nils Minor — Fri, 13 Dec 2013 18:45:11 GMT

Hi,

Thank you for remember my Problem. Yes after attachment i got the PWM working on my application. So thank you for your update.

kind regards, Nils

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

ovrebekk — Fri, 13 Dec 2013 18:42:06 GMT

Hi again

I made some change to the PWM library, and have uploaded a new version below:

Changes include:

Fixed a bug that would lead to an inverted output in certain circumstances
Changed the API to be more in line with the rest of the SDK, using a config struct to initialize the driver
Added a define in the header allowing the PWM library to be used in a "SoftDevice mode", where it detects whether or not the SoftDevice is enabled so that the PWM library can be initialized at any time

I don't know if you ever solved your issue Nils?

Best regards Torbjørn

Simple PWM v1.2.zip

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

ovrebekk — Mon, 02 Sep 2013 11:31:19 GMT

As for turning off the LED, can't you just write 0 to that PWM channel? That will disable the GPIOTE and set the output to 0 manually.

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

ovrebekk — Mon, 02 Sep 2013 11:29:51 GMT

Hi all

I agree an example like this would be useful in the SDK. Maybe we can get something like it in the future ;)
If you try to run pwm_init after enabling the SoftDevice it will trigger an exception. The reason for this is that pwm_init accesses the PPI peripheral directly, without going through the SoC Library API defined by the SoftDevice. It is possible to modify the PWM library to use the SoC Library, but then it will not work without the SD. This was the easiest way to make it work both with or without the SD.
The PWM output is assigned to actual pins a couple of times in the code, each time it is using the PIN configuration stored in the pwm_io_ch[] array. Please have a look in the PWM_IRQHandler function, where the pin is controlled either through the GPIOTE or by the nrf_gpio_pin_write() function.
Are you calling nrf_pwm_init with just 2 parameters when PWM_NUM_CHANNELS is 3? If you want to use just one PWM channel you should change the define to 1.

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

sd — Fri, 30 Aug 2013 09:16:06 GMT

Basically, I'm trying to implement a pwm_stop() and pwm_start() functions (the pwm is used for pulsing an LED, which works). But after a few hours trying to make that work, I'm looking for help here ;) Frustrating.

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

sd — Fri, 30 Aug 2013 09:08:14 GMT

What's the easiest way to disable the PWM and set the pin to 'OFF'. There's seems to have so many options for disabling stuff, but nothing seems to turn the LED OFF! Any hint is appreciated.

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

sd — Wed, 28 Aug 2013 13:15:48 GMT

Something strange is happening with this code. When I use PWM_NUM_CHANNELS 3 and use nrf_pwm_init(14, 8, 10, PWM_MODE_MTR_100); I get output on pin 14. But when I use PWM_NUM_CHANNELS 3 and nrf_pwm_init(14, PWM_MODE_MTR_100); for some reason the output is on pin 19! (LED_1 on the Evaluation Kit.) This is with the example above (not my own code).

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Nils Minor — Wed, 28 Aug 2013 12:13:31 GMT

with this function you can choose the pwm output pins nrf_pwm_init (8,9,10,PWM_MODE_MTR_100);

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Bastiaan — Wed, 28 Aug 2013 11:17:23 GMT

Thanks for this! I'm a bit confused as to which bit in the code assigns the PWM output to an actual pin...?

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Guest — Wed, 28 Aug 2013 11:17:23 GMT

Thanks for this! I'm a bit confused as to which bit in the code assigns the PWM output to an actual pin...?

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Nils Minor — Wed, 28 Aug 2013 10:55:10 GMT

Hi, I've got one question more. Why do i have to init pwm_init before enableing the Softdevice?

best regards Nils

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Nils Minor — Wed, 28 Aug 2013 10:40:05 GMT

Hi, thanks for your answer.

Great example it works fine thank you. I think it would be easier, if such an example comes with the sdk, ist pretty helpful :)

I would accept this answer but ts not my topi it belongs to "sd"

Thank you for helping :)

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

ovrebekk — Tue, 27 Aug 2013 11:13:23 GMT

Hi all

Please have a look at the attached example. It allows you to configure up to 3 IO's to run PWM, and gives you some different modes to pick from (varying base frequency, resolution).

It will work with or without the SoftDevice, as long as you make sure torun the pwm_init() function before enabling the SoftDevice.

This should not be considered an official Nordic example by the way ;)

Best regards Torbjørn

Simple PWM v1.0.zip

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Nils Minor — Tue, 27 Aug 2013 10:32:53 GMT

No one have any other sample code for me? best regards Nils

RE: Is there an example code for using PWM on the nRF51822 with a SoftDevice?

Nils Minor — Tue, 27 Aug 2013 07:12:20 GMT

HI thanks for the answer,

But i need more help, it doesen#t work or i don't know how to use your code.

best regards Nils