how to resign pins in saadc example

[Cindy]

Hi 

I'm not familiar with C language, I tested the saadc example in SDK, it worked well in P0.02

But I dont see how they set CH[X].PSELP or CH[X].PSELN (V(p) and V(n)) in main.c

I dont know how to implement this code to work with other ADC pins.  

Please help me with it and correct me if I was wrong. 

I'm using nrf52 dk and segger embedded studio. 

Cindy

[ovrebekk]

Hi Cindy

These parameters can be found in the channel_config struct, which is used to initialize the ADC channel inside the saadc_init() function. 

By default this function will just use the default settings, defined by the NRFX_SAADC_DEFAULT_CHANNEL_CONFIG_SE(PIN_P) macro, but you can override the various parameters after initializing the struct if you like. 

As an example, to override the positive pin, you just run the following code: 

channel_config.pin_p = NRF_SAADC_INPUT_AIN1;

Then the full saadc_init() function would look like this:

Best regards
Torbjørn

[Cindy]

does pwm_simple has ses version? how can I open it in ses?

it doesnt have ses folder like other examples 

https://devzone.nordicsemi.com/f/nordic-q-a/28081/is-there-a-simple-example-how-to-set-a-pwm-driver/110654#110654

[ovrebekk]

Hi Cindy

The pwm_simple example was made before SES was the main IDE, and as such there is no SES project file for this example. 

What you can do is open some other simple peripheral project in SES, and copy inn the code from the main.c file in the pwm_simple example.

Best regards
Torbjørn

[Cindy]

Thanks, I made it work with another example. I see in the pwm_simple it used LED_1 (How can I change it to another pin? does non-ADC pin works?), but I don't see how they set duty_cycle here. 

[ovrebekk]

Hi Cindy

To change the output pin you just have to change the OUTPUT_PIN define on line 61 of main.c to something else. 

Any pin can be used, as long as it's not used for something else. 

Which pins are used for buttons and LED's is printed on the back of the nRF52DK. 

Best regards
Torbjørn

[Cindy]

Can you make an example of how to change it into a non-LED pin? what about the duty cycle?

[ovrebekk]

Hi Cindy

You can just replace "LED_1" with the GPIO number of your choice. 

For instance, to use P0.08 set it like this:

#define OUTPUT_PIN 8

The duty cycle is set by calling the pwm_update_duty_cycle(uint8_t duty_cycle) function with a number between 0 and 100. 

Best regards
Torbjørn