52810 Use 14bit ADC to read parameter from sensor ，the different 52810 that read paramater are different 。it affects the precision of my equipment

[spring.liu]

this is ADC config     

Fullscreen 5047.u_saadc.c Download

/**
  ******************************************************************************
  * File Name          : u_saadc.c
  * Description        : This file provides code for the xxx operation
  *                      of smoke modules.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2022 WONZ.
  * All rights reserved.</center></h2>
  *
  * @version			V1.0.01
  * @date				2022-5-10
  ******************************************************************************
  */
#include "nrf_drv_saadc.h"
#include "u_saadc.h"
#include "u_heat.h"
#include "nrf_temp.h"
#include "u_timer.h"

#define ADC_CHINAL_NUM						8
#define ADC_CIRCLE_NUM						10
#define SAMPLES_IN_BUFFER 					(ADC_CHINAL_NUM)
#define ADC_AVERAGE_CAL(sum,max,min)		(((sum) - (max) - (min))/(ADC_CIRCLE_NUM-2))
#define CH_RES_OFFSET						(3)


void Get_ADC_Stop(void);
SensorTypedef sensor_val;
static nrf_saadc_value_t     m_buffer_pool[SAMPLES_IN_BUFFER];
static int16_t adc_buf[ADC_CHINAL_NUM*ADC_CIRCLE_NUM];
static uint8_t adc_circle_num = 0;
uint8_t sw_bat_p4;

/**
  * @brief	saadc_callback      
  * @param			   
  *			
  * @retval	none
  * @author	Ethan.deng
  */
void Saadc_Callback(nrf_drv_saadc_evt_t const * p_event)
{   
	uint8_t n;
    if (p_event->type == NRF_DRV_SAADC_EVT_DONE){
        ret_code_t err_code;
		for(n = 0;n < ADC_CHINAL_NUM;n++)adc_buf[adc_circle_num*ADC_CHINAL_NUM + n] = p_event->data.done.p_buffer[n];
        err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, SAMPLES_IN_BUFFER);
        APP_ERROR_CHECK(err_code);
		
		adc_circle_num++;
		if(adc_circle_num >= ADC_CIRCLE_NUM)
		{
			Get_ADC_Value(adc_buf,ADC_CHINAL_NUM*ADC_CIRCLE_NUM);
			adc_circle_num = 0;
		}
		else nrf_drv_saadc_sample();
    }
}
int16_t voltage_val[ADC_CHINAL_NUM] = {0};
static int16_t adc_offset;
int16_t adc_bak[ADC_CHINAL_NUM*2+2];
/**
  * @brief	Get_ADC_Value      
  * @param			   
  *			
  * @retval	none
  * @author	Ethan.deng
  */
void Get_ADC_Value(int16_t * p_buffer, uint16_t size)
{
	int32_t adc_val_sum[ADC_CHINAL_NUM] = {0};
	int16_t adc_val_max[ADC_CHINAL_NUM] = {0};
	int16_t adc_val_min[ADC_CHINAL_NUM] = {16384,16384,16384,16384,16384,16384,16384,16384};
	//int16_t voltage_val[ADC_CHINAL_NUM] = {0};
	
	Get_ADC_Stop();
	//�����С��ֵ
	for(char i=0; i<(ADC_CHINAL_NUM*ADC_CIRCLE_NUM); i++){
		char chl_num = i % ADC_CHINAL_NUM;
		adc_val_sum[chl_num] += p_buffer[i];
		if(p_buffer[i] > adc_val_max[chl_num]){
			adc_val_max[chl_num] = p_buffer[i];
		}	
		else if(p_buffer[i] < adc_val_min[chl_num]){
			adc_val_min[chl_num] = p_buffer[i];
		}
	}

	extern uint8_t res_check_ch;
	for(char i=0; i<ADC_CHINAL_NUM; i++){
		if(sw_bat_p4 == 0)voltage_val[i] = ADC_AVERAGE_CAL(adc_val_sum[i],adc_val_max[i],adc_val_min[i])*7200 / 16384;
		else voltage_val[i] = ADC_AVERAGE_CAL(adc_val_sum[i],adc_val_max[i],adc_val_min[i]);
	}
	
	if(sw_bat_p4 == 0)sensor_val.bat_voltage = voltage_val[7];
	else
	{
		if(res_check_ch == 1)
		{
			sensor_val.ch1_res_val = RES_SIMPLE_CAL(voltage_val[1]-adc_offset,voltage_val[0]);
			sensor_val.ch2_res_val = RES_SIMPLE_CAL(voltage_val[3]-adc_offset,voltage_val[2]);
			adc_offset = (voltage_val[4]+voltage_val[5]+voltage_val[6]+voltage_val[7])/4;
			for(char i=0; i<ADC_CHINAL_NUM; i++)adc_bak[i] = voltage_val[i];
			adc_bak[ADC_CHINAL_NUM*2] = adc_offset;
		}
		else if(res_check_ch == 2)
		{
			sensor_val.ch3_res_val = RES_SIMPLE_CAL(voltage_val[5]-adc_offset,voltage_val[4]) + CH_RES_OFFSET;
			sensor_val.ch4_res_val = RES_SIMPLE_CAL(voltage_val[7]-adc_offset,voltage_val[6]) + CH_RES_OFFSET;
			adc_offset = (voltage_val[0]+voltage_val[1]+voltage_val[2]+voltage_val[3])/4;
			for(char i=ADC_CHINAL_NUM; i<ADC_CHINAL_NUM*2; i++)adc_bak[i] = voltage_val[i-ADC_CHINAL_NUM];
			adc_bak[ADC_CHINAL_NUM*2+1] = adc_offset;
		}
	}
}

/**
  * @brief	SAADC_Init      
  * @param			   
  *			
  * @retval	none
  * @author	Ethan.deng
  */
void Saadc_Init(void)
{
    //���ͨ������
    ret_code_t err_code;
	
	nrf_gpio_cfg(        
		AD_CH_SW_PIN,
		NRF_GPIO_PIN_DIR_OUTPUT,
		NRF_GPIO_PIN_INPUT_DISCONNECT,
		NRF_GPIO_PIN_NOPULL,
		NRF_GPIO_PIN_S0S1,
		NRF_GPIO_PIN_NOSENSE);
	
//	nrf_saadc_channel_config_t channel_0_config =
//        NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_DIFFERENTIAL(NRF_SAADC_INPUT_AIN0,NRF_SAADC_INPUT_AIN1);
//	nrf_saadc_channel_config_t channel_1_config =
//        NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_DIFFERENTIAL(NRF_SAADC_INPUT_AIN2,NRF_SAADC_INPUT_AIN3);
//	nrf_saadc_channel_config_t channel_2_config =
//        NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_DIFFERENTIAL(NRF_SAADC_INPUT_AIN4,NRF_SAADC_INPUT_AIN5);
//	nrf_saadc_channel_config_t channel_3_config =
//        NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_DIFFERENTIAL(NRF_SAADC_INPUT_AIN6,NRF_SAADC_INPUT_AIN7);
	
	
	nrf_saadc_channel_config_t channel_0_config =
        NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN0);
    nrf_saadc_channel_config_t channel_1_config =
        NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN1);
	nrf_saadc_channel_config_t channel_2_config =
		NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN2);
	nrf_saadc_channel_config_t channel_3_config =
		NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN3);
	nrf_saadc_channel_config_t channel_4_config =
		NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN4);	
	nrf_saadc_channel_config_t channel_5_config =
        NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN5);
    nrf_saadc_channel_config_t channel_6_config =
        NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN6);
	nrf_saadc_channel_config_t channel_7_config =
		NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN7);
	
    err_code = nrf_drv_saadc_init(NULL, Saadc_Callback);
    APP_ERROR_CHECK(err_code);
    
    err_code = nrf_drv_saadc_channel_init(0, &channel_0_config);
    APP_ERROR_CHECK(err_code);
    err_code = nrf_drv_saadc_channel_init(1, &channel_1_config);
    APP_ERROR_CHECK(err_code);
    err_code = nrf_drv_saadc_channel_init(2, &channel_2_config);
    APP_ERROR_CHECK(err_code);
    err_code = nrf_drv_saadc_channel_init(3, &channel_3_config);
    APP_ERROR_CHECK(err_code);
    err_code = nrf_drv_saadc_channel_init(4, &channel_4_config);
    APP_ERROR_CHECK(err_code);
	err_code = nrf_drv_saadc_channel_init(5, &channel_5_config);
    APP_ERROR_CHECK(err_code);
    err_code = nrf_drv_saadc_channel_init(6, &channel_6_config);
    APP_ERROR_CHECK(err_code);
    err_code = nrf_drv_saadc_channel_init(7, &channel_7_config);
    APP_ERROR_CHECK(err_code);

	//��������һ��������
    err_code = nrf_drv_saadc_buffer_convert(m_buffer_pool,SAMPLES_IN_BUFFER);
    APP_ERROR_CHECK(err_code);

	//nrf_temp_init();
}
/**
  * @brief	SAADC_Deinit      
  * @param			   
  *			
  * @retval	none
  * @author	Ethan.deng
  */
void Saadc_Deinit(void)
{
	nrf_drv_saadc_channel_uninit(0);
	nrf_drv_saadc_channel_uninit(1);
	nrf_drv_saadc_channel_uninit(2);
	nrf_drv_saadc_channel_uninit(3);
	nrf_drv_saadc_channel_uninit(4);
	nrf_drv_saadc_channel_uninit(5);
	nrf_drv_saadc_channel_uninit(6);
	nrf_drv_saadc_channel_uninit(7);
	nrf_drv_saadc_uninit();
	nrf_gpio_cfg_default(AD_CH_SW_PIN);
}


/**
  * @brief	Get_ADC_Start      
  * @param			   
  *			
  * @retval	none
  * @author	Ethan.deng
  */
volatile uint8_t adc_on_flag = 0;
void Get_ADC_Start(void)
{
	if(adc_on_flag == 1)return;
	adc_on_flag = 1;
	SW_TO_BAT();
	sw_bat_p4 = 0;
	nrf_drv_saadc_sample();
}

/**
  * @brief	Get_ADC_Stop      
  * @param			   
  *			
  * @retval	none
  * @author	Ethan.deng
  */
void Get_ADC_Stop(void)
{
	adc_on_flag = 0;
	RES_CHECK_OFF_CH1();
	RES_CHECK_OFF_CH2();
}

/**
  * @brief	Get_Mcu_Temperature      
  * @param			   
  *			
  * @retval	none
  * @author	Ethan.deng
  */
void Get_Mcu_Temperature(void)
{
	NRF_TEMP->TASKS_START = 1;
	while (NRF_TEMP->EVENTS_DATARDY == 0){}
	NRF_TEMP->EVENTS_DATARDY = 0;
	sensor_val.mcu_temp = nrf_temp_read()/4;
	NRF_TEMP->TASKS_STOP = 1;
}



/************************ (C) COPYRIGHT WONZ **************************/
                          /*****END OF FILE*****/

• This is the electronic schematic

Q13open，CURR N1和CURR P1 get parameter from temperature sensor 。OUT1 is temperature sensor，it was 0.5Ω resistance。
   

that is different 52810 use the same  temperature sensor ！the parameter as follow

  

10357 9747？

looking for your answer 

thanks

[Karl Ylvisaker]

Hello,

52810 Use 14bit ADC to read parameter from sensor ，the different 52810 that read paramater are different 。it affects the precision of my equipment

Have I understood it correctly that you have multiple nRF52810s that are running with different SAADC configurations, producing different outputs?
If so, could you detail what the different configurations are, and how the different outputs diverge from what you would have expected?

I unfortunately do not speak Chinese, and so I would have to ask that you pose the questions in English so that I may advise you on your issue.

Best regards.
Karl

[spring.liu]

• Please look again because the browser translation automatically becomes Chinese

[Karl Ylvisaker]

Hello,

Thank you for editing it to English.

Please see my questions from the previous comment:

Have I understood it correctly that you have multiple nRF52810s that are running with different SAADC configurations, producing different outputs?
If so, could you detail what the different configurations are, and how the different outputs diverge from what you would have expected?

Best regards,
Karl

[spring.liu]

the same configurations that  14bit 8channels  single-ended mode

[Karl Ylvisaker]

Thank you for confirming, but please see the rest of my questions as well, particularly:

How does the outputs diverge from what you would have expected?
It is not entirely clear from the posted screenshot of the outputs.
Additionally, do you have the datasheet of the temperature sensor you are working with? What is the expected part-to-part variance with respect to accuracy?

Best regards,
Karl