BLE_UART example and UART Driver

RE: BLE_UART example and UART Driver

ovrebekk — Wed, 26 May 2021 06:51:55 GMT

Hi Nikolai.

Sorry for the slow reply, I have been on leave for the last 4 months. If you are still having issues with this I suggest you open a new case, since this one is getting old and fragmented. You can point to this one if you like, and it will most likely be assigned to me.

Regards
Torbjørn

RE: BLE_UART example and UART Driver

NikTheNordicUser — Thu, 25 Feb 2021 18:03:01 GMT

Hi , i finally finished my examinations and had time to continue back working on this project.. firstly wanted to thank you for your reply.. secondly I was thinking of changing to timers as u insisted however looking at your example provided I was a bit confused. 'in my application I basically require a timer to be on for a certain period depending on the value entered into the uart terminal of the client development board.

As an example

if I enter the word RPM300 in the uart terminal I need to extract the 300 into an integer and then look into the 300th position in an array where I have all the appropriate periods ranging from RPM of 0 - 300 where in the case of 300 it translates into 5 micro seconds which then I need to switch a timer on with a period of 5us (square wave) and keep it on until i receive another command

RE: BLE_UART example and UART Driver

NikTheNordicUser — Tue, 12 Jan 2021 09:23:38 GMT

ok understood thank you ill use timers

RE: BLE_UART example and UART Driver

ovrebekk — Tue, 12 Jan 2021 07:35:04 GMT

Good luck. If you have any questions or comments just let me know 🙂

RE: BLE_UART example and UART Driver

awneil — Mon, 11 Jan 2021 10:56:01 GMT

So it's not PWM at all, then - it is Frequency Modulation (FM).

So a PWM driver is not what you're looking for.

RE: BLE_UART example and UART Driver

NikTheNordicUser — Mon, 11 Jan 2021 10:52:18 GMT

ill take a look and let you know than you for ur suggestions 🙂

RE: BLE_UART example and UART Driver

NikTheNordicUser — Mon, 11 Jan 2021 10:51:51 GMT

because the change in freuqency is wat changes the speed of the motor controller. It does not behave like other motor controller that requires a constant frequency but a duty change from 1-2us. The motor changes speed by keeping constant duty cycle but change in frequency from 0Hz up to a max of 200kHz

i agree its strange but that's how it is :/

RE: BLE_UART example and UART Driver

ovrebekk — Mon, 11 Jan 2021 10:45:32 GMT

Hi Nikolai

In case you end up going down the TIMER/PPI/GPIOTE route, I shared a similar example in an earlier case:
https://devzone.nordicsemi.com/f/nordic-q-a/68673/pwm-library-simpler-way-for-on-off-enable-disable-than-the-example-with-sdk

If you have any issues with it just let me know.

Best regards
Torbjørn

RE: BLE_UART example and UART Driver

awneil — Fri, 08 Jan 2021 10:39:16 GMT

But why do you need to change the PWM frequency ?

As the name suggests, PWM is normally just about changing (ie, Modulating) the Pulse Width - not changing the frequency.

RE: BLE_UART example and UART Driver

NikTheNordicUser — Fri, 08 Jan 2021 10:33:40 GMT

i need to change the PWM around every 1-2min as I am measuring rotational accelaeation and gyro results from an inertial sensor and the point of the project is to ensure that the measured data is equal to the input RPM

RE: BLE_UART example and UART Driver

ovrebekk — Thu, 07 Jan 2021 15:22:35 GMT

Hi Nikolai

Approximately how often do you need to change the PWM frequency?

Do you only need a single output, or multiple?

The PWM peripheral is not very well suited for applications where you want to change the frequency rather than the duty cycle, since by default the frequency is fixed and only the duty cycle changes.

In this case it might be better to setup a timer module to generate events at your desired frequency, and connect these events to a pin through the PPI and GPIOTE peripherals.

Then you simply need to change the compare value of the timer in order to change the frequency of the pin.

Best regards
Torbjørn

RE: BLE_UART example and UART Driver

NikTheNordicUser — Wed, 06 Jan 2021 09:17:23 GMT

Thank you for your reply it is very helpful, my only concern is that I constantly need to update the frequency rather than the dutycycle. In my application the user will need to enter some value like RPM300 (300 rpms for a motor) where the 300 is extracted and depending on the value I change the frequency of the PWM for example RPM300 means PWM of period 5us and the duty cycle Is always on 50% etc.... where the RPM ranges from 0-300 RPM.

In my case where i had the uarte and pwm i was using the pwm library and i had a lookup table (array with all periods) and depending on the value of RPM it will get the period from that array.

can this be done n the same manner

or can the pwm part be changed to using the library rather than driver?

what do you think please?

RE: BLE_UART example and UART Driver

ovrebekk — Tue, 29 Dec 2020 15:40:56 GMT

Hi Nikolai

You mentioned you were using the ble_app_uart_c example as reference?

This example already has the UART enabled, so adding this should not be necessary.

I modified the example to also include PWM, so you can see how this is done.

The example here (just unzip to \nRF5_SDK_17.0.2_d674dde\examples\ble_central):

devzone.nordicsemi.com/.../ble_5F00_app_5F00_uart_5F00_c_5F00_pwm.zip

Patch file here, if you just want to see what I changed:

devzone.nordicsemi.com/.../change.patch

Best regards
Torbjørn

RE: BLE_UART example and UART Driver

NikTheNordicUser — Mon, 28 Dec 2020 19:31:44 GMT

can u hep me ?

RE: BLE_UART example and UART Driver

NikTheNordicUser — Thu, 24 Dec 2020 10:25:07 GMT

is it possible to maybe share your code of the Christmas tree ?

RE: BLE_UART example and UART Driver

NikTheNordicUser — Thu, 24 Dec 2020 09:31:15 GMT

hi i tried it and it didnt really work but it could be due to code placement , do I but the uart and pwm functions under the ble ?

or the other way around

RE: BLE_UART example and UART Driver

NikTheNordicUser — Mon, 21 Dec 2020 22:28:50 GMT

Ok thanks for the fast response ill have a go at it

RE: BLE_UART example and UART Driver

awneil — Mon, 21 Dec 2020 22:15:49 GMT

[quote userid="93218" url="~/f/nordic-q-a/69775/ble_uart-example-and-uart-driver"]is it possible to combine them all together[/quote]

Yes: NUS + PWM + UART: https://devzone.nordicsemi.com/community/f/wireless-forum/69754/nrf52-ble-christmas-tree

[quote userid="93218" url="~/f/nordic-q-a/69775/ble_uart-example-and-uart-driver"]some help on how to properly do it[/quote]

For the BLE, start with the NUS example from the SDK. Get that going, and understand how it works.

Then merge your PWM & UART into that.