beta.c File Reference

Resistive divider used for measuring temperature. More...

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

Include dependency graph for beta.c:

Go to the source code of this file.

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.

Copyright

© 2010 - 2021, Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V. All rights reserved.

SPDX-License-Identifier: BSD-3-Clause

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 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 the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER 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.

We kindly request you to use one or more of the following phrases to refer to foxBMS in your hardware, software, documentation or advertising materials:

• ″This product uses parts of foxBMS®″
• ″This product includes parts of foxBMS®″
• ″This product is derived from foxBMS®″

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

#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))

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

#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))

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_mV

voltage 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.

Here is the call graph for this function:

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_ddegC

in 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_Ohm

resistance in Ohm

Returns

corresponding temperature in deci °C

Definition at line 126 of file beta.c.