saadc blocking issue

I can run the SAADC example and read the analog inputs fine, now I've modified the code to simply read the adc with the blocking nrf_drv_saadc_sample_convert call

All I get back is 0's on the read....using the same input AIN1 in the example program with a callback works and shows values?

One thing I note, if I change the config to have a acquisition time of 3us it reads values...but anything higher (like the default 40us) it reads 0?

in Main I do these steps:

nrf_saadc_channel_config_t cfg = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN1);

nrf_drv_saadc_channel_init(NRF_SAADC_INPUT_AIN1,&cfg);

while(1)

{

nrf_pwr_mgmt_run();

retval = nrf_drv_saadc_sample_convert(NRF_SAADC_INPUT_AIN1,&myval);
if (retval == NRF_SUCCESS)
{
NRF_LOG_INFO("TESTING ch1=%d ",myval);
}

NRF_LOG_FLUSH();

}

Top Replies

ericalbers over 7 years ago in reply to Håkon Alseth +1

Thank you, oddly, I paste your code in and it works....and bringing my code back also now works....yet I have changed no code....I think the problem must be between keyboard and screen :-) Thanks!

Parents

0 Håkon Alseth over 7 years ago

Hi,

I tried to cut down the saadc example in the SDK to run as you've done, and it seems to work as intended at my end.

My pin is floating, and therefore prints ADC values between 0 and 800, but when grounding or pulling the pin to VDD, I see ~0 (GND) and ~800 (VDD)

Attached is my example program.

Best regards,

Håkon

Fullscreen main.c Download

/**
 * Copyright (c) 2014 - 2017, Nordic Semiconductor ASA
 * 
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 * 
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 * 
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 * 
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 * 
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 */
/** @file
 * @defgroup nrf_adc_example main.c
 * @{
 * @ingroup nrf_adc_example
 * @brief ADC Example Application main file.
 *
 * This file contains the source code for a sample application using ADC.
 *
 * @image html example_board_setup_a.jpg "Use board setup A for this example."
 */

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "nrf.h"
#include "nrf_drv_saadc.h"
#include "nrf_drv_ppi.h"
#include "nrf_drv_timer.h"
#include "boards.h"
#include "app_error.h"
#include "nrf_delay.h"
#include "app_util_platform.h"
#include "nrf_pwr_mgmt.h"
#include "nrf_drv_power.h"


#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

#define SAMPLES_IN_BUFFER 5
volatile uint8_t state = 1;

static const nrf_drv_timer_t m_timer = NRF_DRV_TIMER_INSTANCE(0);
static nrf_saadc_value_t     m_buffer_pool[2][SAMPLES_IN_BUFFER];
static nrf_ppi_channel_t     m_ppi_channel;
static uint32_t              m_adc_evt_counter;


void saadc_callback(nrf_drv_saadc_evt_t const * p_event)
{
    if (p_event->type == NRF_DRV_SAADC_EVT_DONE)
    {
        ret_code_t err_code;

        err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, SAMPLES_IN_BUFFER);
        APP_ERROR_CHECK(err_code);

        int i;
        NRF_LOG_INFO("ADC event number: %d", (int)m_adc_evt_counter);

        for (i = 0; i < SAMPLES_IN_BUFFER; i++)
        {
            NRF_LOG_INFO("%d", p_event->data.done.p_buffer[i]);
        }
        m_adc_evt_counter++;
    }
    NRF_LOG_INFO("ADC ISR");
}


/**
 * @brief Function for main application entry.
 */
int main(void)
{
    uint32_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();

    err_code = nrf_drv_power_init(NULL);
    APP_ERROR_CHECK(err_code);

    ret_code_t ret_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(ret_code);

    NRF_LOG_INFO("SAADC HAL simple example.");
    err_code = nrf_drv_saadc_init(NULL, saadc_callback);
    APP_ERROR_CHECK(err_code);
    nrf_saadc_channel_config_t cfg =  NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN1);
    cfg.acq_time = NRF_SAADC_ACQTIME_40US;

    nrf_drv_saadc_channel_init(NRF_SAADC_INPUT_AIN1,&cfg);

    while (1)
    {
        nrf_pwr_mgmt_run();
        static nrf_saadc_value_t myval;
        err_code = nrf_drv_saadc_sample_convert(NRF_SAADC_INPUT_AIN1,&myval);
        if (err_code == NRF_SUCCESS)
        {   
            NRF_LOG_INFO("TESTING ch1=%d ",myval);
        }
        nrf_delay_ms(100);
        NRF_LOG_FLUSH();
        
    }
}


/** @} */

Reply