bms/Application/app/iv_measure.c

#include "iv_measure.h"
#include "bsp/ml5238.h"
#include "bsp/cs1180.h"
#include "bsp/gd32_adc.h"
#include "bsp/clock.h"
/* measure the current & voltage for battery pack by using
 * ms5238 & cs1180(only used when bms is in small current loading)
*/

/* this is the inited gain set to the ms5238, but the really gain is  calibrated
*  by measure_system_calibrate
*/
static float imon_gain_10x = 10.0f;
static float imon_gain_50x = 50.0f;
static float imon_gain_now;
static float vim0_10x = 0.0f;
static float vim0_50x = 0.0f;
static float vim0_now;
#define r_resistor 1.0f // 1ºÁÅ·
#define r_pcb_resistor 2.0f // pcb resistor
static float r_sense = r_resistor + r_pcb_resistor;
static float v_ref = 3300.0f; //adc ref = 3.3v
static float max_adc = 65535.0f;

static void __inline__ select_gain_10x(int select){
	if (select){
		ML5238_IMON_OUT_10X();
		imon_gain_now = imon_gain_10x;
		vim0_now = vim0_10x;
	}else {
		ML5238_IMON_OUT_50X();
		imon_gain_now = imon_gain_50x;
		vim0_now = vim0_50x;
	}
}


/*calibrate when startup && temperature is changed more than 5? degree
* calibrate the ms5238's IMON output voltage gain
*/
void current_calibrate(void){
	/* calibrate the 10x gain */
	ML5238_IMON_OUT_ZERO_10X();
	vim0_10x = adc_sample(ADC_CHAN_IMON ,TRUE);
	ML5238_IMON_OUT_V2000_10X();
	float vim1 = adc_sample(ADC_CHAN_IMON, FALSE);
	ML5238_IMON_OUT_V100_10X();
	float vr = adc_sample(ADC_CHAN_IMON, FALSE);
	imon_gain_10x = ML5238_GAIN(vim0_10x, vim1, vr);

	/* calibrate the 50x gain */
	ML5238_IMON_OUT_ZERO_50X();
	vim0_50x = adc_sample(ADC_CHAN_IMON ,TRUE);
	ML5238_IMON_OUT_V2000_50X();
	vim1 = adc_sample(ADC_CHAN_IMON, FALSE);
	ML5238_IMON_OUT_V100_50X();
	vr = adc_sample(ADC_CHAN_IMON, FALSE);
	imon_gain_50x = ML5238_GAIN(vim0_50x, vim1, vr);

	select_gain_10x(0);//default gain is 50x, if 50x overflow, use 10x

}

void measure_system_init(void){
	adc_init();
	ml5238_init();
	cs1180_init();
	current_calibrate();
}

float get_imon_current(bool calibration){
	float adc = adc_sample(ADC_CHAN_IMON, calibration);
	if (adc >= 0xFFF0){
		//overflow, use 10x
		if (imon_gain_now == imon_gain_50x){
			select_gain_10x(1);
			adc = adc_sample(ADC_CHAN_IMON, calibration);
		}
	}
	float cali_adc = ML5238_V_RSENSER(adc, vim0_now, imon_gain_now);

	return (cali_adc/max_adc) * v_ref / r_sense;
}

float get_vmon_voltage(int cell, bool calibration){
	ml5238_select_cell_to_vmon(cell);
	delay_us(50);
	float adc = adc_sample(ADC_CHAN_VMON, calibration);

	return adc/max_adc * v_ref;
}