how to change gpio pin voltage/current levels

[saiteja]

Hi, i am working on Pancake motor C0820B006F circuit and it is connected to P0.12 pin and ground iam usin NRF52 development board. i want to change the pan cake vibrator frequency by changing Pin0.12 voltage or current. how to change the current/voltage at certain PIN to change frequency level of vibrator.

Thank you.

##EDIT :-

/* 2-channel PWM, 200Hz, output on DK LED pins. */ app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_1CH(200L, BSP_LED_0);

       /* 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(&PWM,&pwm1_cfg,pwm_ready_callback);
       APP_ERROR_CHECK(err_code);
       app_pwm_enable(&PWM);

       uint32_t value;

          APP_ERROR_CHECK(err_code);
       while(true)
       {

           for (uint8_t i = 0; i < 40; ++i)
           {
               value = (i < 20) ? (i * 5) : (100 - (i - 20) * 5);
               //printf("value = %d\n",value);
               ready_flag = false;
               /* Set the duty cycle - keep trying until PWM is ready... */
               while (app_pwm_channel_duty_set(&PWM, 0, value) == NRF_ERROR_BUSY);

               /* ... or wait for callback. */
               while(!ready_flag);
               APP_ERROR_CHECK(app_pwm_channel_duty_set(&PWM, 1, value));
               nrf_delay_ms(50);

           }

       }

[AmbystomaLabs]

You can't drive this motor directly from the nRF. The spec sheet says it draws 100mA. The nRF52 can provide max 10mA in high drive mode. Also there is no DAC capability with nRF52. GPIO are either on or off. The only solution you can do is drive the pin as PWM and through a low pass filter use a fet or bjt to drive the motor.

[AmbystomaLabs]

Oh, I just remembered that when I wrote the updated DTM code for PA/LNA support I did a version with a timer on the PPI. Just look for my posting on DTM for the code. It should be easy for you to copy out the timer bit and reuse it for your application.