foxBMS  1.2.1
The foxBMS Battery Management System API Documentation
beta.c File Reference

Resistive divider used for measuring temperature. More...

#include "beta.h"
#include "foxmath.h"
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Macros

#define BETA_KELVIN   (273.15f)
 
#define BETA_ADC_VOLTAGE_V_MAX_V    (float)((BETA_RESISTOR_DIVIDER_SUPPLY_VOLTAGE_V * BETA_ResistanceFromTemperature(1400)) / (BETA_ResistanceFromTemperature(1400) + BETA_RESISTOR_DIVIDER_RESISTANCE_R_1_R_2_Ohm))
 
#define BETA_ADC_VOLTAGE_V_MIN_V    (float)((BETA_RESISTOR_DIVIDER_SUPPLY_VOLTAGE_V * BETA_ResistanceFromTemperature(-400)) / (BETA_ResistanceFromTemperature(-400) + BETA_RESISTOR_DIVIDER_RESISTANCE_R_1_R_2_Ohm))
 

Functions

int16_t BETA_GetTemperatureFromBeta (uint16_t adcVoltage_mV)
 returns temperature based on measured ADC voltage More...
 
int16_t BETA_TemperatureFromResistance (float resistance_Ohm)
 returns temperature corresponding to NTC resistance More...
 
float BETA_ResistanceFromTemperature (int16_t temperature_ddegC)
 returns NTC resistance corresponding to temperature, used to compute Vmin and Vmax of the divider More...
 

Detailed Description

Resistive divider used for measuring temperature.

SPDX-License-Identifier: BSD-3-Clause

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Author
foxBMS Team
Date
2020-01-17 (date of creation)
Updated
2021-03-22 (date of last update)
Prefix
BETA

Definition in file beta.c.

Macro Definition Documentation

◆ BETA_ADC_VOLTAGE_V_MAX_V

Defines for calculating the ADC voltage on the ends of the operating range. The ADC voltage is calculated with the following formula:

V_adc = ( ( V_supply * R_ntc ) / ( R + R_ntc ) )

Depending on the position of the NTC in the voltage resistor (R_1/R_2), different R_ntc values are used for the calculation.

Definition at line 77 of file beta.c.

◆ BETA_ADC_VOLTAGE_V_MIN_V

Defines for calculating the ADC voltage on the ends of the operating range. The ADC voltage is calculated with the following formula:

V_adc = ( ( V_supply * R_ntc ) / ( R + R_ntc ) )

Depending on the position of the NTC in the voltage resistor (R_1/R_2), different R_ntc values are used for the calculation.

Definition at line 79 of file beta.c.

◆ BETA_KELVIN

#define BETA_KELVIN   (273.15f)

inverse temperature coefficient for ideal gas

Definition at line 62 of file beta.c.

Function Documentation

◆ BETA_GetTemperatureFromBeta()

int16_t BETA_GetTemperatureFromBeta ( uint16_t  adcVoltage_mV)

returns temperature based on measured ADC voltage

Parameters
adcVoltage_mVvoltage in mV
Returns
corresponding temperature in deci °C or FLT_MAX/FLT_MIN if NTC is shorted or got disconnected. The caller of this functions needs to check for these return values to prevent invalid data.

Definition at line 95 of file beta.c.

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◆ BETA_ResistanceFromTemperature()

float BETA_ResistanceFromTemperature ( int16_t  temperature_ddegC)

returns NTC resistance corresponding to temperature, used to compute Vmin and Vmax of the divider

Parameters
temperature_ddegCin deci °C
Returns
corresponding resistance in Ohm

Definition at line 140 of file beta.c.

◆ BETA_TemperatureFromResistance()

int16_t BETA_TemperatureFromResistance ( float  resistance_Ohm)

returns temperature corresponding to NTC resistance

Parameters
resistance_Ohmresistance in Ohm
Returns
corresponding temperature in deci °C

Definition at line 126 of file beta.c.