CN115267561A - A method of using an external fuel gauge to detect battery power on the MTK platform - Google Patents

Abstract

The invention discloses a method for realizing battery electric quantity detection by using an external fuel gauge on an MTK platform, and relates to the technical field of battery electric quantity detection. The invention can reduce the workload of the system by accurately monitoring the voltage, the current and the temperature of the battery and outputting the electric quantity of the battery in real time, has smaller power consumption, is more suitable for the application of portable equipment, can measure the voltage and the temperature of the battery by sampling through an analog-digital converter and calculating through a calculation formula, improves the applicability, prolongs the service life of the battery by monitoring the battery and using the battery more scientifically, and avoids the sudden change of the electric quantity in the detection process by arranging a battery monitoring chip STC3100 in a coulometer and connecting the STC3100 with an MTK platform and calculating the electric quantity through a mathematical formula, thereby being simpler and more accurate.

Description

A method of using an external fuel gauge to detect battery power on the MTK platform

technical field

The invention relates to the technical field of battery power detection, in particular to a method for realizing battery power detection by using an external fuel gauge on an MTK platform.

Background technique

Lithium batteries have the advantages of high storage energy, long life, light weight and no memory effect, and have been widely used in current portable devices, especially in consumer electronic devices such as mobile phones, multimedia players, and GPS terminals. These devices not only support a single communication function, but also support functions such as streaming media playback and high-speed wireless transmission and reception. With the addition of more and more functions and the need to obtain a longer charge time, the capacity of lithium batteries in portable devices is also increasing. Taking smartphones as an example, the mainstream battery capacity has increased from 800mAH to 1500mAH now. , and there is an increasing trend.

With the use of large-capacity batteries, if the device can accurately understand the power of the battery, it will not only protect the battery well and prevent it from over-discharging, but also allow the user to accurately know the remaining power to estimate the time it can be used. Important data is saved in a timely manner, therefore, in PMP and GPS, fuel gauges are continuously added to the device.

During the detection process of the existing battery power detection method, the detection result is not accurate enough, the detection process is relatively complicated, and the voltage and temperature of the battery cannot be detected, and the health condition of the battery cannot be monitored.

Contents of the invention

The purpose of the present invention is to provide a method for detecting battery power by using an external fuel gauge on the MTK platform, so as to solve the problems in the background technology.

In order to solve the problems of the technologies described above, the present invention is achieved through the following technical solutions:

The present invention is a kind of method that uses external fuel gauge to realize battery power detection on MTK platform, comprises the following steps:

step one:

Prepare a coulomb counter, set the battery monitoring chip STC3100 in the coulomb counter, connect the STC3100 to the MTK platform, connect the battery to the coulomb counter, set a current detection resistor in the coulomb counter, and connect the current detection resistor to the positive or negative pole of the battery in series. Or when flowing out of the battery, the current generates a voltage Vsense across the resistor;

The integration of the current and time is the changing power, so it can accurately track the battery power change, with an accuracy of up to 1%, although the coulomb counter has a problem with the initial estimation of the battery, and the accuracy of the current resistance directly affects the accuracy of the power; However, with the monitoring of battery voltage and temperature, some software algorithms can better reduce the influence of factors such as lithium initial power estimation, battery aging, and current detection resistor accuracy on the measurement results.

Step two:

The coulomb counter in the STC3100 is provided with a clock used as a time base for calculating electric quantity;

The STC3100 is a battery monitoring chip with a coulomb counter from STMicroelectronics. It can monitor the voltage, temperature, and current of the battery, and integrates a programmable 12-14-bit analog-to-digital converter. The hardware integrator is used for the coulomb counter function. Calculated, the measured current can reach up to 2.5A, the integrator can use a 7000mAh battery, and the resolution can reach 0.2mAh.

Step three:

The voltage on the current detection resistor is placed in the REG_CURRET register after being sampled by the analog-to-digital converter, and the least significant bit of the analog-to-digital converter is 11.7uV, and the actual current value flowing is calculated according to formula (1):

I ₁ ＝REG _CURRET ×11×77/R _cg (1)

R _cg is the resistance value of the current detection resistor;

Step four:

The STC3100 will multiply the voltage value at both ends of Rcg by the sampling period and put it into a 28-bit accumulator, and the upper 16 bits will be put into the REG_CHARGE register, according to formula (2):

G(s)=K/(1+Ts) (2)

After calculating the actual voltage value, obtain the actual remaining power, where T is the initial time value, K is the inertial link gain, and s is a variable in the complex frequency domain;

Step five:

The STC3100 can also measure the battery voltage and temperature, and transmit the calculation results to the MTK platform.

The STC3100 has an I2C interface to communicate with the processor, and integrates 32 bytes of RAM for storing battery power or other characteristic information.

The clock in the second step is an internal clock, which is connected between the Rosc pin and the ground through a 200 kohm 0.1% resistor, and the precision of the internal clock is 2.5% within the range of its power supply voltage and operating temperature.

The current sampling resistor Rcg is used to collect the current flowing into or out of the battery. Due to the sampling limitation of the analog-to-digital converter, the voltage drop of the resistor cannot exceed +/-80mV, so the resistance value is determined by the maximum peak current in the application. .

The power supply pin Vcc of the STC3100 itself is separated from the battery voltage detection pin Vin.

The battery voltage is placed in the REG_VOLTAGE register after being sampled by the analog-to-digital converter, according to formula (3):

V=REG _VOLTAGE ×2.44 (3).

The temperature is placed in the REG_TEMPERATURE register after being sampled by the analog-to-digital converter, according to formula (4):

V=REG _TEMPERATURE ×0.125 (4).

The GND pin of the STC3100 should be connected to the ground terminal of the resistor with a PCB trace;

Among them, the STC3100 register can directly read the change value of power, battery voltage, current, temperature and other data. When the system processor is powered on, configure the register of the STC3100 to start its power counting function. If it is the first power-on , the initial estimation of the battery capacity is required through the detected battery voltage. After the initial estimation is completed, the real-time calculation of the battery power can be performed in real time.

The present invention has the following beneficial effects:

The present invention reduces the workload of the system by accurately monitoring the battery voltage, current, and temperature, and outputs the battery power in real time, and it has relatively small power consumption, which is more suitable for the application of portable devices. And through the calculation formula, the voltage and temperature of the battery can be measured, which improves the applicability. By monitoring the battery, the battery is used more scientifically, and the service life of the battery is extended. The battery monitoring chip STC3100, STC3100 and MTK platform are set in the coulomb meter Connection, the power is calculated through mathematical formulas, and the detection process avoids sudden changes in power, which is simpler and more accurate.

Of course, any product implementing the present invention does not necessarily need to achieve all the above-mentioned advantages at the same time.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that are required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Fig. 1 is a kind of flow chart of the method for using external fuel gauge to realize battery power detection in MTK platform in the present invention;

FIG. 2 is a structural block diagram of the power supply pin and the battery voltage monitoring pin of the STC3100 of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

In the description of the present invention, it should be understood that the terms "upper", "middle", "outer", "inner" and the like indicate orientation or positional relationship, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or It should not be construed as limiting the invention by implying that a referenced component or element must have a particular orientation, be constructed and operate in a particular orientation.

In this embodiment, a method for using an external fuel gauge to detect battery power on the MTK platform includes the following steps:

step one:

Prepare a coulomb counter, set the battery monitoring chip STC3100 in the coulomb counter, connect the STC3100 to the MTK platform, connect the battery to the coulomb counter, set a current detection resistor in the coulomb counter, and connect the current detection resistor to the positive or negative pole of the battery in series. Or when flowing out of the battery, the current generates a voltage Vsense across the resistor;

Step two:

The coulomb counter in STC3100 sets a clock used as the time base for calculating the power;

Step three:

The voltage on the current detection resistor is sampled by the analog-to-digital converter and placed in the REG_CURRET register, and the least significant bit of the analog-to-digital converter is 11.7uV, so that the actual current value that flows can be calculated according to formula (1):

I ₁ ＝REG _CURRET ×11×77/R _cg (1)

R _cg is the resistance value of the current detection resistor;

Step four:

STC3100 will multiply the voltage value at both ends of Rcg by the sampling period and put it into a 28-bit accumulator, and the upper 16 bits will be put into the REG_CHARGE register, which can be according to formula (2):

G(s)=K/(1+Ts) (2)

After calculating the actual voltage value, obtain the actual remaining power, where T is the initial time value, K is the inertial link gain, and s is a variable in the complex frequency domain;

Step five:

STC3100 can also measure the battery voltage and temperature, and transmit the calculation results to the MTK platform.

STC3100 has an I2C interface to communicate with the processor side, and integrates 32bytes of RAM for storing battery power or other characteristic information.

The clock in step 2 is an internal clock, which is connected between the Rosc pin and the ground through a 200kohm 0.1% resistor, and the precision of the internal clock is 2.5% within the range of its power supply voltage and operating temperature.

The current sampling resistor Rcg is used to collect the current flowing into or out of the battery. Due to the sampling limitation of the analog-to-digital converter, the voltage drop of this resistor cannot exceed +/-80mV, so the resistance value is determined by the maximum peak current in the application.

STC3100's own power supply pin Vcc and battery voltage detection pin Vin are separated.

The battery voltage is sampled by the analog-to-digital converter and placed in the REG_VOLTAGE register, according to formula (3):

V=REG _VOLTAGE ×2.44 (3).

After the temperature is sampled by the analog-to-digital converter, it is placed in the REG_TEMPERATURE register, according to formula (4):

V=REG _TEMPERATURE ×0.125 (4).

The GND pin of the STC3100 should be connected to the ground terminal of the resistor with a PCB trace.

In the description of this specification, descriptions with reference to the terms "one embodiment", "example", "specific example" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment of the present invention. In an embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the invention disclosed above are only to help illustrate the invention. The preferred embodiments are not exhaustive in all detail, nor are the inventions limited to specific embodiments described. Obviously, many modifications and variations can be made based on the contents of this specification. This description selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The invention is to be limited only by the claims, along with their full scope and equivalents.

Claims (8)

1. A method for realizing battery power detection by using an external fuel gauge on an MTK platform is characterized by comprising the following steps:

the method comprises the following steps:

preparing a coulometer, wherein a battery monitoring chip STC3100 is arranged in the coulometer, the STC3100 is connected with a computer carrying an MTK platform, the battery is connected with the coulometer, a current detection resistor is arranged in the coulometer, the current detection resistor is connected with the anode or the cathode of the battery in series, and when current flows into or out of the battery, the current generates voltage Vsense at two ends of the resistor;

step two:

the coulomb meter in the STC3100 is provided with a clock used as a time base for calculating the electric quantity;

step three:

the voltage across the current sensing resistor is sampled by the analog-to-digital converter and placed in a register named REG _ current, and the least significant bit of the analog-to-digital converter is 11.7uV, and the actual current value flowing is calculated according to equation (1):

I₁＝REG_CURRET×11×77/R_cg (1)

R_cgthe resistance value of the current detection resistor;

step four:

the STC3100 multiplies the voltage across Rcg by the sampling period and puts the multiplied voltage into a 28-bit accumulator, and the upper 16 bits of the accumulator are put into a register called REG _ CHARGE, according to equation (2):

G(s)＝K/(1+Ts) (2)

after calculating an actual voltage value, acquiring actual residual electric quantity, wherein T is an initial time value, K is an inertia link gain, and s is a variable in a complex frequency domain;

step five:

the STC3100 may also measure battery voltage and temperature and transmit the calculation to the MTK platform.

2. The method for detecting battery power using an external fuel gauge in an MTK platform according to claim 1, wherein: the STC3100 is provided with an I2C interface for communicating with the processor side and is integrated with a RAM of 32bytes for storing the battery capacity or other characteristic information.

3. The method of claim 2, wherein the method comprises the following steps: the clock in the second step is an internal clock which is connected between the Rosc pin and the ground through a resistor, and the accuracy of the internal clock is 2.5% in the range of the power supply voltage and the working temperature.

4. The method for detecting battery power using an external fuel gauge in an MTK platform according to claim 3, wherein: the current sampling resistor Rcg is used to collect the current flowing into or out of the battery, and the voltage drop of the resistor cannot exceed +/-80mV due to the sampling limit of the analog-to-digital converter, so the resistance value is determined by the maximum peak current in the application.

5. The method of claim 4, wherein the method comprises the following steps: the STC3100 has its own power supply pin Vcc and battery voltage detection pin Vin separated.

6. The method of claim 5, wherein the method comprises the following steps: the battery VOLTAGE is sampled by an analog-to-digital converter and then placed in a register named REG _ VOLTAGE according to equation (3):

V＝REG_VOLTAGE×2.44 (3)。

7. the method of claim 6, wherein the method comprises the following steps: the TEMPERATURE is sampled by an analog-to-digital converter and placed in a register named REG _ temparature according to equation (4):

V＝REG_TEMPERATURE×0.125 (4)。

8. the method of claim 7, wherein the method comprises the following steps: the GND grounding terminal pin of the STC3100 is connected with the grounding terminal of the resistor by a PCB wire.

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