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
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
does pwm_simple has ses version? how can I open it in ses?
it doesnt have ses folder like other examples
Can you make an example of how to change it into a non-LED pin? what about the duty cycle?
Thanks for your help, it's all very helpful.
is there any way I can change the clock to a lower frequency, it seems 125kHz is the lower frequency this function can do?
because I want to use a speaker here, I want the frequency is around 2kHz.
maybe I didn't do it right, please correct me.
Thanks,
Cindy
the reason why I want to adjust the frequency is that my speaker isn't very loud with current code, I thought it's because the frequency is too high so the speaker can't have a high decibel level.
Yesterday, I tried pwm_library, /** @file
* @defgroup pwm_example_main main.c
* @{
* @ingroup pwm_example
*
* @brief PWM Example Application main file.
*
* This file contains the source code for a sample application using PWM.
*
*
*/
#include <stdbool.h>
#include <stdint.h>
#include "nrf.h"
#include "app_error.h"
#include "bsp.h"
#include "nrf_delay.h"
#include "app_pwm.h"
APP_PWM_INSTANCE(PWM1,1); // Create the instance "PWM1" using TIMER1.
static volatile bool ready_flag; // A flag indicating PWM status.
void pwm_ready_callback(uint32_t pwm_id) // PWM callback function
{
ready_flag = true;
}
int main(void)
{
ret_code_t err_code;
/* 1-channel PWM, 100000 microseconds period = 0.1 second , output on pin 28. */
app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_1CH(1000L, 28);
/* Switch the polarity of the second channel. */
pwm1_cfg.pin_polarity[1] = APP_PWM_POLARITY_ACTIVE_HIGH;
/* Initialize and enable PWM. */
err_code = app_pwm_init(&PWM1,&pwm1_cfg,pwm_ready_callback);
APP_ERROR_CHECK(err_code);
app_pwm_enable(&PWM1);
//DUTY CYCLE SET TO 50%
while (app_pwm_channel_duty_set(&PWM1, 0, 10) == NRF_ERROR_BUSY);
while (true)
{
// Configure pin 5 as output
nrf_gpio_cfg_output(4);
// Set pin 5 high
nrf_gpio_pin_set(4);
nrf_delay_ms(1000);
// Set pin 5 low
nrf_gpio_pin_clear(4);
nrf_delay_ms(1000);
}
}
/** @} */
"app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_1CH(1000L, 28);" (1kHz)
by changing the perid of time, I think I changed the frequncy?
But it's still not very loud. Please let me know if I did it right?
btw, I tested this speaker with Arduino, I used their tone function.
Here's the description of their tone function
Generates a square wave of the specified frequency (and 50% duty cycle) on a pin. A duration can be specified, otherwise the wave continues until a call to noTone(). The pin can be connected to a piezo buzzer or other speaker to play tones.
Only one tone can be generated at a time. If a tone is already playing on a different pin, the call to tone() will have no effect. If the tone is playing on the same pin, the call will set its frequency.
So I think I need a simple square wave.
Could it because the speaker doesn't get enough current?
https://media.digikey.com/pdf/Data%20Sheets/CUI%20Inc%20All%20Brands%20PDFs/CCV-084B16-SMT.pdf
here's the datasheet of the speaker I'm using.
Thanks for your help.
Cindy
