foxBMS  1.5.1
The foxBMS Battery Management System API Documentation
beta.h
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41 
42 /**
43  * @file beta.h
44  * @author foxBMS Team
45  * @date 2020-01-17 (date of creation)
46  * @updated 2023-02-23 (date of last update)
47  * @version v1.5.1
48  * @ingroup TEMPERATURE_SENSORS
49  * @prefix BETA
50  *
51  * @brief Resistive divider used for measuring temperature
52  *
53  * V_supply
54  * --.--
55  * |
56  * +-.-+
57  * | |
58  * | | R_1
59  * | |
60  * +-.-+
61  * |
62  * .--- V_adc
63  * |
64  * +-.-+
65  * | |
66  * | | R_2
67  * | |
68  * +-.-+
69  * |
70  * --.--
71  * GND
72  *
73  */
74 
75 #ifndef FOXBMS__BETA_H_
76 #define FOXBMS__BETA_H_
77 
78 /*========== Includes =======================================================*/
79 
80 #include <math.h>
81 #include <stdint.h>
82 
83 /*========== Macros and Definitions =========================================*/
84 /**
85  * Position of the NTC in the voltage resistor
86  * true: NTC is positioned above the voltage tap for the ADC voltage.
87  * This equals resistor R_1 in the above circuit diagram
88  *
89  * false: NTC is positioned below the voltage tap for the ADC voltage.
90  * This equals resistor R2 in the above circuit diagram
91  */
92 #define BETA_POSITION_IN_RESISTOR_DIVIDER_IS_R_1 (false)
93 
94 /** Resistor divider supply voltage in volt */
95 #define BETA_RESISTOR_DIVIDER_SUPPLY_VOLTAGE_V (4.096f)
96 
97 /**
98  * Resistance value of the other resistor (not the NTC) in the resistor
99  * divider in kOhm.
100  */
101 #define BETA_RESISTOR_DIVIDER_RESISTANCE_R_1_R_2_Ohm (10000.0f)
102 
103 /** Reference temperature */
104 #define BETA_T_REF_C (25.0f)
105 
106 /** NTC resistance at reference temperature */
107 #define BETA_R_REF_Ohm (10000.0f)
108 
109 /** BEta coefficient of the NTC */
110 #define BETA_BETACOEFFICIENT (3984.0f)
111 
112 /*========== Extern Constant and Variable Declarations ======================*/
113 
114 /*========== Extern Function Prototypes =====================================*/
115 /**
116  * @brief returns temperature based on measured ADC voltage
117  * @param adcVoltage_mV voltage in mV
118  * @return corresponding temperature in deci &deg;C or FLT_MAX/FLT_MIN if NTC
119  * is shorted or got disconnected. The caller of this functions needs
120  * to check for these return values to prevent invalid data.
121  */
122 extern int16_t BETA_GetTemperatureFromBeta(uint16_t adcVoltage_mV);
123 
124 /**
125  * @brief returns temperature corresponding to NTC resistance
126  * @param resistance_Ohm resistance in Ohm
127  * @return corresponding temperature in deci &deg;C
128  *
129  */
130 extern int16_t BETA_TemperatureFromResistance(float_t resistance_Ohm);
131 
132 /**
133  * @brief returns NTC resistance corresponding to temperature,
134  * used to compute Vmin and Vmax of the divider
135  * @param temperature_ddegC in deci &deg;C
136  * @return corresponding resistance in Ohm
137  *
138  */
139 extern float_t BETA_ResistanceFromTemperature(int16_t temperature_ddegC);
140 
141 /*========== Externalized Static Functions Prototypes (Unit Test) ===========*/
142 #ifdef UNITY_UNIT_TEST
143 #endif
144 
145 #endif /* FOXBMS__BETA_H_ */
float_t BETA_ResistanceFromTemperature(int16_t temperature_ddegC)
returns NTC resistance corresponding to temperature, used to compute Vmin and Vmax of the divider
Definition: beta.c:149
int16_t BETA_TemperatureFromResistance(float_t resistance_Ohm)
returns temperature corresponding to NTC resistance
Definition: beta.c:135
int16_t BETA_GetTemperatureFromBeta(uint16_t adcVoltage_mV)
returns temperature based on measured ADC voltage
Definition: beta.c:104