JP7587137B2 - Electronics - Google Patents

Description

The present invention relates to electronic devices.

In recent years, many electronic devices are controlled by processors, making software indispensable. In addition, in such electronic devices, it is common to update the software when it is revised.

For example, Patent Document 1 describes a method of executing a software update when the current battery voltage value is greater than a battery remaining capacity threshold. The battery remaining capacity threshold is set according to the size of the software to be updated and the type of non-volatile memory that stores information such as the capacity of the software.

JP 2006-85534 A

However, the technology described in Patent Document 1 requires the setting of a battery remaining capacity threshold. In addition, for batteries that have the characteristic that the voltage remains almost constant until just before the battery runs out and then the voltage drops suddenly, it is difficult to set the battery remaining capacity threshold. Even if the battery voltage value is greater than the battery remaining capacity threshold, if the voltage drops suddenly, the power will be cut off during the software update. This causes the problem of software update failure.

One aspect of the present invention aims to update software more reliably.

In order to solve the above problems, an electronic device according to one aspect of the present invention includes an operating unit that operates on battery power according to software, a memory that stores the software, and an update control unit that updates the software in the memory when the difference in voltage between the first terminal voltage of the battery when the battery power is not supplied to the operating unit and the second terminal voltage of the battery when the battery power is supplied to the operating unit is equal to or less than a predetermined voltage, but does not update the software in the memory when the difference in voltage exceeds the predetermined voltage.

According to one aspect of the present invention, software can be updated more reliably.

1 is a block diagram showing a wireless communication device according to an embodiment of the present invention; 2 is a block diagram showing a control unit of the wireless communication device; 10 is a flowchart showing a process for determining whether firmware update can be performed by the wireless communication device. 1 is a characteristic diagram showing the relationship between the terminal voltage of a battery and the usage time of the battery, and a characteristic diagram showing the relationship between the differential voltage and the usage time of the battery corresponding to the characteristic diagram.

[Embodiment]
Hereinafter, one embodiment of the present invention will be described with reference to FIGS.

(Configuration of wireless communication device)
FIG. 1 is a block diagram showing a wireless communication device 1 according to the present embodiment.

As shown in FIG. 1, the wireless communication device 1 (electronic device) includes a transmitter 2, a receiver 3, a transmission/reception switching circuit 4, an antenna 5, a display 6, an operation unit 7, an interface 8, a program memory 9 (memory), a battery 10, a voltage detection unit 11, a switch 12, and a control unit 13. In FIG. 1, the interface 8 is indicated as I/F.

The transmitting unit 2 performs a transmission process that converts the input voice into a transmission signal. To perform the transmission process, the transmitting unit 2 has a microphone 21, an A/D converter 22, a modulation unit 23, a D/A converter 24, a BPF (Band Pass Filter) 25, an ALC (Automatic Level Control) circuit 26, and a power amplifier 27. In FIG. 1, the microphone 21 is indicated as MIC, the A/D converter 22 is indicated as A/D, the D/A converter 24 is indicated as D/A, the ALC circuit 26 is indicated as ALC, and the power amplifier 27 is indicated as PA.

In the transmission unit 2, the audio signal output from the microphone 21 is converted to a digital signal by the A/D converter 22, and then modulated into a modulated signal by the modulation unit 23 using a predetermined modulation method. The modulated signal is converted to an analog signal by the D/A converter 24, and then only a predetermined band is passed by the BPF 25. The input level of the modulated signal that has passed through the BPF 25 to the power amplifier 27 is limited by the ALC circuit 26. The power of the modulated signal that has passed through the ALC circuit 26 is amplified by the power amplifier 27 to the level of power required for communication.

The transmission signal output from the transmitter 2 is output to the antenna 5 via the transmission/reception switching circuit 4. The antenna 5 radiates the input transmission signal as radio waves. On the other hand, the antenna 5 outputs the reception signal received as radio waves to the transmission/reception switching circuit 4. This reception signal is input to the receiver 3 via the transmission/reception switching circuit 4.

The transmission/reception switching circuit 4 is a circuit that switches between the connection between the transmission unit 2 and the antenna 5 and the connection between the reception unit 3 and the antenna 5. The transmission/reception switching circuit 4 is configured to include a semiconductor switch, a relay (particularly a latching relay), etc.

The receiving unit 3 performs a receiving process to convert the received signal into sound. To perform the receiving process, the receiving unit 3 has a BPF (Band Pass Filter) 31, an A/D converter 32, a demodulation unit 33, a D/A converter 34, and a speaker 35. In FIG. 1, the A/D converter 32 is indicated as A/D, the D/A converter 34 is indicated as D/A, and the speaker 35 is indicated as SP.

In the receiver 3, the band of the input received signal is limited by the BPF 31, converted to a digital signal by the A/D converter 32, and then demodulated to an audio signal by the demodulator 33 using a predetermined demodulation method. The audio signal from the demodulator 33 is converted to an analog signal by the D/A converter 34 and input to the speaker 35. The speaker 35 outputs audio corresponding to the input signal.

The display unit 6 displays various information created by the control unit 13 to make it visible. The operation unit 7 has a PTT switch and various operation buttons, accepts operations using the PTT switch and operation buttons, and outputs an operation signal corresponding to the operation to the control unit 13.

In the wireless communication device 1, the transmitter 2, receiver 3, transmission/reception switching circuit 4, antenna 5, display 6, and operation unit 7 constitute an operating unit 101 that operates using power from a battery 10 in accordance with firmware described below.

The interface 8 is provided to accept firmware (software) supplied from the outside. The firmware is software that allows the control unit 13 to control the operating unit 101.

Interface 8 is an interface for connecting a memory card when the firmware is stored in a memory card. Alternatively, interface 8 is an interface for connecting a communication cable when the firmware is transmitted from another device (e.g., a personal computer) via a communication cable.

The program memory 9 is a non-volatile memory for storing firmware. The program memory 9 is composed of, for example, a flash ROM, an EEPROM (registered trademark) (Electronically Erasable and Programmable Read Only Memory), etc.

The battery 10 is composed of a primary battery such as a dry cell, or a secondary battery such as a lithium ion battery. Power from the battery 10 is constantly supplied to the program memory 9 and the control unit 13.

The voltage detection unit 11 detects the terminal voltage of the battery 10. The voltage detection unit 11 includes a level conversion circuit (such as a circuit consisting of only voltage-dividing resistors, or a circuit including voltage-dividing resistors and an amplifier) that converts the terminal voltage into a voltage within the conversion voltage range of the A/D converter in order to input the detected terminal voltage to an A/D converter that constitutes a voltage reading unit 131 (see FIG. 2) of the control unit 13, which will be described later.

The switch 12 is provided in the power supply path 102 for supplying power from the battery 10 to the operating unit 101. The switch 12 is a normally-off switch.

The control unit 13 controls the operation unit 101. Specifically, the control unit 13 controls the switching operation of the transmission/reception switching circuit 4 based on an operation signal from the operation unit 7, creates information corresponding to the current operating state of the wireless communication device 1, and supplies the information to the display unit 6. The control unit 13 also updates the firmware stored in the program memory 9.

(Configuration of the control unit)
Next, a configuration for updating firmware by the control unit 13 will be described.

As shown in FIG. 2, the control unit 13 has a voltage reading unit 131, a memory unit 132, a determination unit 133, and an update control unit 134 to perform firmware updates. The control unit 13 is configured, for example, by a microcontroller including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an A/D converter, a timer, etc. The above-mentioned program memory 9 may be incorporated in the control unit 13 and configured by a ROM. In this case, the ROM is configured by the above-mentioned flash ROM, EEPROM (registered trademark), etc.

The voltage reading unit 131 reads the terminal voltage of the battery 10 detected by the voltage detection unit 11. The voltage reading unit 131 is configured, for example, by an A/D converter of the microcontroller described above, and reads the terminal voltage by converting the input analog terminal voltage into a digital terminal voltage.

The memory unit 132 temporarily stores the terminal voltage read by the voltage reading unit 131 in response to an instruction from the update control unit 134. For this reason, the memory unit 132 is configured with the above-mentioned RAM. The memory unit 132 stores the terminal voltage (first terminal voltage) when power from the battery 10 is not being supplied to the operation unit 101, and the terminal voltage (second terminal voltage) when power from the battery 10 is being supplied to the operation unit 101.

The determination unit 133 compares the difference voltage between the first terminal voltage and the second terminal voltage stored in the memory unit 132 with a predetermined threshold voltage. If the difference voltage is equal to or less than the predetermined voltage, the determination unit 133 determines that the firmware can be updated, and if the difference voltage exceeds the predetermined voltage, the determination unit 133 determines that the firmware cannot be updated.

The update control unit 134 is provided as part of the functions of the CPU described above in order to control firmware updates. The update control unit 134 starts a series of processes related to firmware updates in response to user operations on the operation unit 7. The update control unit 134 causes the display unit 6 to display that the firmware is being updated during the firmware update process. The update control unit 134 controls the ON/OFF (opening and closing) operation of the switch 12, and controls the writing operation of the memory unit 132. If the determination unit 133 determines that the firmware can be updated, the update control unit 134 executes the firmware update process, whereas if the determination unit 133 determines that the firmware cannot be updated, the update control unit 134 does not execute the firmware update process.

(Firmware update process)
Next, a description will be given of a firmware update process by the control unit 13. Fig. 3 is a flowchart showing a process procedure for determining whether or not a firmware update can be executed by the wireless communication device 1. Fig. 4 is a characteristic diagram showing the relationship between the terminal voltage of the battery 10 and the usage time of the battery 10, and a characteristic diagram showing the relationship between the differential voltage and the usage time of the battery 10 corresponding to the characteristic diagram.

As shown in FIG. 3, first, the update control unit 134 determines whether or not a start instruction to start a firmware update has been received from the operation unit 7 in response to a user's operation of the operation unit 7 (step S1). If there is no start instruction (NO in step S1), the update control unit 134 waits until a start instruction is received (YES in step S1). In this state, the switch 12 is OFF. In this state, a small current flows through parts of the wireless communication device 1, such as the program memory 9 and the operation unit of the control unit 13.

When the update control unit 134 receives the start instruction, it stores the first terminal voltage V1 read by the voltage reading unit 131 in the memory unit 132 (step S2). Next, the update control unit 134 turns on the switch 12 (step S3) and determines whether a predetermined time has elapsed (step S4). The timing in the control unit 13 is performed, for example, by the timer described above. In this state, current flows through the program memory 9, the control unit 13 operating unit, and also through the operating unit 101, so a large current flows in the wireless communication device 1.

If the predetermined time has not elapsed (NO in step S4), the update control unit 134 waits until the predetermined time has elapsed (YES in step S4). The predetermined time is set, for example, to a time slightly longer than the time it takes for the terminal voltage of the battery 10 to stabilize after the switch 12 changes from the OFF state to the ON state.

When a predetermined time has elapsed since the switch 12 was turned ON, the update control unit 134 stores the second terminal voltage V2 read by the voltage reading unit 131 in the memory unit 132 (step S5) and turns off the switch 12.

When the determination unit 133 receives a notification from the update control unit 134 that the switch 12 has been turned OFF, it determines whether the differential voltage ΔV between the first terminal voltage V1 and the second terminal voltage V2 is equal to or less than the predetermined voltage Vth (step S7).

If the update control unit 134 determines in step S7 that the differential voltage ΔV is equal to or less than the predetermined voltage, i.e., if it determines that a firmware update can be performed, it executes the firmware update (step S8) and ends the process. The update control unit 134 executes the update by overwriting the firmware stored in the program memory 9 with the firmware for update imported via the interface 8. While the firmware update is being performed, the update control unit 134 causes the display unit 6 to display that a firmware update is being performed.

In addition, while the firmware update is being performed, the switch 12 is in the OFF state. Since the operating unit 101 is not operated while the firmware update is being performed, unnecessary power consumption by the operating unit 101 can be reduced.

If the update control unit 134 determines in step S7 that the differential voltage ΔV exceeds the predetermined voltage, i.e., if it determines that the firmware update cannot be performed, it stops the firmware update (step S9) and ends the process. In this case, the update control unit 134 causes the display unit 6 to display that the remaining charge of the battery 10 is insufficient and that the firmware update could not be performed.

(effect)
Generally, when the battery has a sufficient remaining charge, the terminal voltage drops slightly even if the load is increased, but when the remaining charge is low, the internal resistance increases, so increasing the load causes a large drop in the terminal voltage. Therefore, when the battery 10 still has a sufficient remaining charge, the voltage difference ΔV is small, and when the battery 10 has a low remaining charge, the voltage difference ΔV is large.

The determination unit 133 determines whether or not a firmware update can be performed based on the differential voltage ΔV between the first terminal voltage in a light load state where no power is supplied to the operating unit 101 and the second terminal voltage in a heavy load state where power is supplied to the operating unit 101. Specifically, as described above, the determination unit 133 determines that a firmware update can be performed if the differential voltage ΔV is equal to or less than the predetermined voltage Vth, and determines that a firmware update cannot be performed if the differential voltage ΔV exceeds the predetermined voltage Vth.

Then, the update control unit 134 executes the firmware update based on the determination by the determination unit 133 that the firmware update is possible. Also, the update control unit 134 cancels (does not execute) the firmware update based on the determination by the determination unit 133 that the firmware update is not possible.

In particular, as shown in FIG. 4, the terminal voltage Vt of a certain type of battery 10 (e.g., a nickel-metal hydride battery) remains at a nearly constant value even after the usage time T has elapsed, but drops sharply just before the battery 10 runs out of power. This makes it difficult to set the battery power threshold based on the terminal voltage Vt, which can lead to problems such as software update failures.

Here, looking at the voltage difference ΔV, at usage time T1 when the battery 10 still has sufficient remaining power, the voltage difference ΔV is small and below the predetermined voltage Vth, so it is correctly determined that the firmware can be updated. On the other hand, at usage time T2 when the battery 10 has little remaining power, the voltage difference ΔV exceeds the predetermined voltage Vth, so it is correctly determined that the firmware cannot be updated.

Therefore, before executing a firmware update, it is possible to determine whether the remaining charge of the battery 10 is sufficient for the firmware update. By not executing a firmware update when the remaining charge of the battery 10 is low, it is possible to avoid the inconvenience of the battery 10 running out of charge while the firmware update is being executed, causing the firmware update to be interrupted.

As described above, the remaining charge of the battery 10 can be predicted to some extent from the change characteristics of the second terminal voltage V2. Therefore, the predetermined voltage Vth is set with a certain margin based on the change characteristics of the second terminal voltage V2 with respect to the usage time T in the above-mentioned heavy load state and the power required for firmware upgrade. The power required for firmware upgrade is calculated in advance based on the size of the firmware. This makes it possible to more accurately determine whether the remaining charge of the battery 10 is sufficient for firmware upgrade.

Furthermore, when the transmission/reception switching circuit 4 is configured using a latching relay, current flows through the coil for driving the movable contact in the latching relay only during switching operation. For this reason, if current flows through the coil when the latching relay is not switched, the current flowing through the operating unit 101 increases, and the amount of decrease in the second terminal voltage V2 can be increased. In this way, by passing a current of a certain magnitude through the operating unit 101 when reading the second terminal voltage, the accuracy of the differential voltage can be improved.

Note that the latching relay is not limited to being used in the transmission/reception switching circuit 4. The latching relay may be used, for example, in a switching circuit that switches between multiple filters (not shown in FIG. 1). Even in such a case, the accuracy of the differential voltage can be improved by increasing the amount of drop in the second terminal voltage V2, as in the above case where a latching relay is used in the transmission/reception switching circuit 4.

[Software implementation example]
The functions of the wireless communication device 1 (hereinafter referred to as the "device") can be realized by a program for causing a computer to function as the device, and a program for causing a computer to function as each control block of the device (particularly each part included in the control unit 13).

In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The control device and storage device execute the program, thereby realizing each of the functions described in each of the above embodiments.

The program may be recorded on one or more computer-readable recording media, not on a temporary basis. The recording media may or may not be included in the device. In the latter case, the program may be provided to the device via any wired or wireless transmission medium.

In addition, some or all of the functions of each of the above control blocks can be realized by logic circuits. For example, an integrated circuit in which a logic circuit that functions as each of the above control blocks is formed is also included in the scope of the present invention.

〔summary〕
The electronic device of this embodiment comprises an operating unit that operates using battery power in accordance with software, a memory that stores the software, and an update control unit that updates the software in the memory when the differential voltage between a first terminal voltage of the battery when battery power is not supplied to the operating unit and a second terminal voltage of the battery when battery power is supplied to the operating unit is equal to or less than a predetermined voltage, but does not update the software in the memory when the differential voltage exceeds the predetermined voltage.

With the above configuration, it is possible to determine whether the remaining battery power is sufficient for the software update before updating the software. By not performing the software update when the remaining battery power is low, it is possible to avoid the inconvenience of the battery running out of power during the software update, causing the software update to be interrupted.

In the electronic device, it is preferable that the predetermined voltage is set based on the change characteristics of the second terminal voltage.

According to the above configuration, the remaining battery charge can be predicted to some extent based on the change characteristics of the second terminal voltage. Therefore, by setting the predetermined voltage based on the characteristics of the second terminal voltage, it is possible to more accurately determine whether the remaining battery charge is sufficient for software updates.

In the electronic device, it is preferable that the operating unit has a latching relay.

According to the above configuration, when a current is passed through the coil when the latching relay is not switched, the current flowing through the operating unit increases, and the amount of drop in the second terminal voltage can be increased. In this way, by passing a current of a certain magnitude through the operating unit when reading the second terminal voltage, the accuracy of the differential voltage can be improved.

The electronic device is preferably a wireless communication device.

The above configuration allows software updates in wireless communication devices to be performed more reliably.

[Additional Notes]
The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

1 Radio communication equipment (electronic equipment)
9 Program Memory (Memory)
10 Battery 101 Operation unit 134 Update control unit V1 First terminal voltage V2 Second terminal voltage ΔV Differential voltage Vth Predetermined voltage

Claims (3)

an operating unit that operates on battery power in accordance with software;
A memory for storing the software;
an update control unit that updates the software in the memory when a difference in voltage between a first terminal voltage of the battery in a state in which power from the battery is not supplied to the operating unit and a second terminal voltage of the battery in a state in which power from the battery is supplied to the operating unit is equal to or less than a predetermined voltage, and does not update the software in the memory when the difference in voltage exceeds the predetermined voltage;
The operating unit has a latching relay,
the update control unit, when acquiring the second terminal voltage, causes a current to flow through a coil of the latching relay so as not to switch the latching relay . The electronic device according to claim 1, characterized in that the predetermined voltage is set based on the change characteristics of the second terminal voltage. 3. The electronic device according to claim 1, wherein the electronic device is a wireless communication device.

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