foxBMS  1.2.0
The foxBMS Battery Management System API Documentation
beta.h
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1 /**
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41 
42 /**
43  * @file beta.h
44  * @author foxBMS Team
45  * @date 2020-01-17 (date of creation)
46  * @updated 2021-02-24 (date of last update)
47  * @ingroup TEMPERATURE_SENSORS
48  * @prefix BETA
49  *
50  * @brief Resistive divider used for measuring temperature
51  *
52  * V_supply
53  * --.--
54  * |
55  * +-.-+
56  * | |
57  * | | R_1
58  * | |
59  * +-.-+
60  * |
61  * .--- V_adc
62  * |
63  * +-.-+
64  * | |
65  * | | R_2
66  * | |
67  * +-.-+
68  * |
69  * --.--
70  * GND
71  *
72  */
73 
74 #ifndef FOXBMS__BETA_H_
75 #define FOXBMS__BETA_H_
76 
77 /*========== Includes =======================================================*/
78 #include "general.h"
79 
80 /*========== Macros and Definitions =========================================*/
81 /**
82  * Position of the NTC in the voltage resistor
83  * true: NTC is positioned above the voltage tap for the ADC voltage.
84  * This equals resistor R_1 in the above circuit diagram
85  *
86  * false: NTC is positioned below the voltage tap for the ADC voltage.
87  * This equals resistor R2 in the above circuit diagram
88  */
89 #define BETA_POSITION_IN_RESISTOR_DIVIDER_IS_R_1 (false)
90 
91 /** Resistor divider supply voltage in volt */
92 #define BETA_RESISTOR_DIVIDER_SUPPLY_VOLTAGE_V (4.096f)
93 
94 /**
95  * Resistance value of the other resistor (not the NTC) in the resistor
96  * divider in kOhm.
97  */
98 #define BETA_RESISTOR_DIVIDER_RESISTANCE_R_1_R_2_Ohm (10000.0f)
99 
100 /** Reference temperature */
101 #define BETA_T_REF_C (25.0f)
102 
103 /** NTC resistance at reference temperature */
104 #define BETA_R_REF_Ohm (10000.0f)
105 
106 /** BEta coefficient of the NTC */
107 #define BETA_BETACOEFFICIENT (3984.0f)
108 
109 /*========== Extern Constant and Variable Declarations ======================*/
110 
111 /*========== Extern Function Prototypes =====================================*/
112 /**
113  * @brief returns temperature based on measured ADC voltage
114  * @param adcVoltage_mV voltage in mV
115  * @return corresponding temperature in deci °C or FLT_MAX/FLT_MIN if NTC
116  * is shorted or got disconnected. The caller of this functions needs
117  * to check for these return values to prevent invalid data.
118  */
119 extern int16_t BETA_GetTemperatureFromBeta(uint16_t adcVoltage_mV);
120 
121 /**
122  * @brief returns temperature corresponding to NTC resistance
123  * @param resistance_Ohm resistance in Ohm
124  * @return corresponding temperature in deci °C
125  *
126  */
127 extern int16_t BETA_TemperatureFromResistance(float resistance_Ohm);
128 
129 /**
130  * @brief returns NTC resistance corresponding to temperature,
131  * used to compute Vmin and Vmax of the divider
132  * @param temperature_ddegC in deci °C
133  * @return corresponding resistance in Ohm
134  *
135  */
136 extern float BETA_ResistanceFromTemperature(int16_t temperature_ddegC);
137 
138 /*========== Externalized Static Functions Prototypes (Unit Test) ===========*/
139 
140 #endif /* FOXBMS__BETA_H_ */
int16_t BETA_TemperatureFromResistance(float resistance_Ohm)
returns temperature corresponding to NTC resistance
Definition: beta.c:126
float BETA_ResistanceFromTemperature(int16_t temperature_ddegC)
returns NTC resistance corresponding to temperature, used to compute Vmin and Vmax of the divider
Definition: beta.c:140
int16_t BETA_GetTemperatureFromBeta(uint16_t adcVoltage_mV)
returns temperature based on measured ADC voltage
Definition: beta.c:95
General macros and definitions for the whole platform.