Hardware watchdog circuit applied to overtime monitoring scene

Abstract

The utility model relates to a hardware watchdog circuit applied to an overtime monitoring scene, which comprises a watchdog chip with the model of TPL5010; the monitoring module is connected with a DONE pin which is arranged on the watchdog chip and is used for inputting a dog feeding signal; the alarm module is connected with an RSTn pin which is arranged on the watchdog chip and is used for outputting an alarm trigger signal; the adjusting module comprises a potentiometer RP1 used for adjusting the maximum dog feeding time interval of the watchdog chip, and the DELAY of the watchdog chip is connected to the ground through the potentiometer RP1. According to the scheme, the maximum dog feeding time interval range of the watchdog circuit is expanded, the maximum dog feeding time interval can be changed between 100ms and 72000s by adjusting the potentiometer, when a dog feeding signal is not received within the set maximum dog feeding time interval, the circuit generates a reset signal and triggers an alarm, and the watchdog circuit is simple in structure, reliable in operation and convenient to operate.

Description

Technical Field

[0001] The utility model relates to the field of timer circuits, and particularly to a hardware watchdog circuit applied to an overtime monitoring scenario. Background Art

[0002] In the field of agricultural machinery sowing monitoring, a monitoring device continuously monitors the sowing situation of a seeder. When no sowing signal is detected for more than a certain period of time, it indicates that the system has a fault and the seeds are stuck, which will cause a certain area of missed sowing. At this time, an alarm reminder is required for timely processing. The traditional alarm monitoring uses a single-chip microcomputer to monitor the sowing signal and time. When the sowing signal sent by the sensor is not received after the timeout, the alarm circuit is triggered. This solution has a high cost and the monitoring timeout interval t IP cannot be adjusted conveniently and quickly according to the usage scenario. In this context, a more simple and flexible low-cost solution is needed to realize the monitoring and alarm of sensing signals. Summary of the Invention

[0003] For the traditional watchdog circuit, its maximum dog feeding time interval is generally in milliseconds and seconds, mainly used for software system reset. When the system software fails or accidentally cannot feed the dog in time, a reset signal is sent to reset and restart the system software. Different from the traditional application scenarios, the hardware watchdog circuit of the utility model is applied to the overtime monitoring scenario, realizing the functions of low-cost, high-reliability and flexible and convenient sensing signal monitoring and alarm, and can be widely applied to scenarios that require overtime monitoring, such as monitoring of missed sowing of a seeder, security timed patrol, etc.

[0004] To achieve the above object, the utility model provides a hardware watchdog circuit applied to an overtime monitoring scenario, which includes:

[0005] A watchdog chip, with the model number TPL5010, whose VDD pin and GND pin are respectively connected to the power supply voltage VCC and ground;

[0006] A monitoring module, connected to the DONE pin of the watchdog chip for inputting a dog feeding signal, and the dog feeding signal is a pulse signal generated by the monitoring module;

[0007] An alarm module, connected to the RSTn pin of the watchdog chip for outputting an alarm trigger signal to trigger an alarm after receiving the alarm trigger signal;

[0008] An adjustment module, the adjustment module includes a potentiometer RP1 for adjusting the maximum dog feeding time interval of the watchdog chip, and the DELAY pin of the watchdog chip is connected to the ground through the potentiometer RP1.

[0009] As a further preferred technical solution of the utility model, the monitoring module includes a switch circuit and / or a sensing circuit;

[0010] The switch circuit includes a switch button S1. One end of the switch button S1 is connected to the supply voltage VCC, and the other end of the switch button S1 is connected to the DONE pin of the watchdog chip;

[0011] The sensing circuit includes a sensor U1 having a transmitting unit and a receiving unit. One end of the transmitting unit is connected to the supply voltage VCC through a resistor R1, and the other end of the transmitting unit is grounded. One end of the receiving unit is connected to the supply voltage VCC, and the other end of the receiving unit is divided into two paths. One path is connected to the ground through a resistor R2, and the other path is connected to the DONE pin of the watchdog chip.

[0012] As a further preferred technical solution of the present invention, the sensor U1 is a groove-type optocoupler sensor or other sensor circuits capable of generating pulse signals within a cycle time.

[0013] As a further preferred technical solution of the present invention, the alarm module includes a resistor R3, a resistor R4, a resistor R5, a triode Q1, and an alarm. The collector of the triode Q1 is connected to the supply voltage VCC through the resistor R3, the base of the triode Q1 is connected to the RSTn pin of the watchdog chip through the resistor R4, both ends of the resistor R5 are respectively connected to the supply voltage VCC and the RSTn pin of the watchdog chip, and both ends of the alarm are respectively connected to the emitter of the triode Q1 and the ground.

[0014] As a further preferred technical solution of the present invention, the alarm can be a light alarm, a sound alarm, or an audible and visual alarm circuit.

[0015] As a further preferred technical solution of the present invention, the maximum watchdog feeding time interval of the watchdog chip is 100 ms to 7200 s.

[0016] The hardware watchdog circuit of the present invention applied to the timeout monitoring scenario, adopting the above technical solutions, can achieve the following beneficial effects:

[0017] 1) The solution of the present invention expands the range of the maximum watchdog feeding time interval. By adjusting the potentiometer, the maximum watchdog feeding time interval can be changed between 100 ms and 72000 s. When no watchdog signal is received within the set maximum watchdog feeding time interval, the circuit generates a reset signal to trigger an alarm. The circuit structure is simple, reliable in operation, and convenient to operate;

[0018] 2) The solution of the present invention has a simple structure, effectively reduces the cost and development complexity of the product, and improves the reliability, flexibility, and application range. Description of the Drawings

[0019] The present utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0020] Figure 1 The figure is a circuit diagram of an embodiment provided for the hardware watchdog circuit of the present utility model applied to the timeout monitoring scenario.

[0021] Figure 2 The figure is a pulse timing diagram of the hardware watchdog circuit of the present utility model applied to the timeout monitoring scenario.

[0022] The implementation, functional features, and advantages of the present utility model will be further described in conjunction with the embodiments with reference to the accompanying drawings. Specific Embodiments

[0023] The present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments. Terms such as "upper", "lower", "left", "right", "middle", and "one" cited in the preferred embodiments are only for the convenience of description and are not used to limit the scope of implementation of the present utility model. Changes or adjustments to their relative relationships shall also be regarded as the scope of implementation of the present utility model without substantial changes in the technical content.

[0024] As Figure 1 shown, the present utility model provides a hardware watchdog circuit applied to the timeout monitoring scenario, including: a watchdog chip TPL5010 (the TPL5010 is the chip model), and a monitoring module, an alarm module, and an adjustment module connected to the watchdog chip TPL5010. The monitoring module and the alarm module are respectively connected to the input and output of the watchdog chip, and the input is used for feeding the dog, and its maximum dog-feeding time interval t IP is controlled by the adjustment module.

[0025] The VDD pin and the GND pin of the watchdog chip are respectively connected to the supply voltage VCC and the ground.

[0026] The monitoring module is connected to the DONE pin on the watchdog chip for inputting the dog feeding signal. The dog feeding signal is a pulse signal (effective at the rising edge of the pulse) and is generated by the monitoring module. Specifically, the monitoring module includes a switching circuit and a sensing circuit, where: the switching circuit includes a switch button S1. One end of the switch button S1 is connected to the supply voltage VCC, and the other end of the switch button S1 is connected to the DONE pin of the watchdog chip; the sensing circuit includes a sensor U1 with a transmitting unit and a receiving unit. Preferably, the sensor U1 is a groove type optocoupler sensor. One end of the transmitting unit is connected to the supply voltage VCC through a resistor R1, and the other end of the transmitting unit is grounded. One end of the receiving unit is connected to the supply voltage VCC, and the other end of the receiving unit is divided into two paths. One path is connected to the ground through a resistor R2, and the other path is connected to the DONE pin of the watchdog chip.

[0027] The alarm module is connected to the RSTn pin on the watchdog chip for outputting an alarm trigger signal to trigger an alarm after receiving the alarm trigger signal (effective at low level). Specifically, the alarm module includes a resistor R3, a resistor R4, a resistor R5, a triode Q1, and a light emitting diode D1. The collector of the triode Q1 is connected to the supply voltage VCC through the resistor R3. The base of the triode Q1 is connected to the RSTn pin of the watchdog chip through the resistor R4. Both ends of the resistor R5 are respectively connected to the supply voltage VCC and the RSTn pin of the watchdog chip. Both ends of the light emitting diode D1 are respectively connected to the emitter of the triode Q1 and the ground. In practical applications, the light emitting diode D1 used as an alarm can also be a sound alarm or an audible and visual alarm circuit.

[0028] The adjustment module includes a potentiometer RP1 for adjusting the maximum dog feeding time interval of the watchdog chip. The DELAY pin of the watchdog chip is connected to the ground through the potentiometer RP1. By adjusting the resistance value of the potentiometer RP1, the maximum dog feeding time interval t IP of the watchdog chip can be set to be from 100 ms to 7200 s.

[0029] 1. Application in monitoring missed seeding of a seeder:

[0030] According to Figure 1 adjust the potentiometer RP1 to set the predetermined maximum dog feeding time interval t IP (such as 3 minutes). If the DONE pin of the watchdog chip TPL5010 does not receive the next seeding monitoring signal sent by the optocoupler sensor for more than 3 minutes, the system will trigger an alarm through the RSTn pin of the watchdog chip TPL5010 to indicate missed seeding. At this time, the light emitting diode D1 will light up. The timing diagram in this application is shown in Figure 2 as follows.

[0031] 2. Security Fixed-Point Patrol Monitoring Application:

[0032] According to Figure 1 Connect the switch button S1 to the dog-feeding pin (DONE pin) of the watchdog chip TPL5010, and adjust the resistance value of the potentiometer RP1 so that the predetermined maximum dog-feeding time interval is 7200 s (2 hours). The security guard patrols the designated area every 2 hours and presses the switch button S1 to punch the card. Then the system will not generate an alarm signal at the RSTn pin. If the switch button S1 is not pressed to punch the card for more than 2 hours, the system will trigger the alarm device through RSTn. At this time, the light-emitting diode D1 will light up to remind the security guard to patrol the designated area on time. The timing diagram in this application is shown in Figure 2 as follows.

[0033] Although the specific implementation manners of the present utility model have been described above, those skilled in the art should understand that these are only examples. Various changes or modifications can be made to this implementation manner without departing from the principle and essence of the present utility model. The protection scope of the present utility model is only defined by the appended claims.

Claims

1. A hardware watchdog circuit applied to a timeout monitoring scenario, characterized in that: include: The watchdog chip, model TPL5010, has its VDD pin connected to the power supply voltage VCC and its GND pin connected to the ground; A monitoring module connected to a DONE pin on the watchdog chip for inputting a dog feeding signal, wherein the dog feeding signal is a pulse signal and is generated by the monitoring module; An alarm module, connected to the RSTn pin of the watchdog chip for outputting an alarm trigger signal, so as to trigger an alarm after receiving the alarm trigger signal; The regulating module comprises a potentiometer RP1 for adjusting a maximum dog feeding time interval of the watchdog chip, and a DELAY pin of the watchdog chip is connected to ground via the potentiometer RP1.

2. The hardware watchdog circuit for timeout monitoring according to claim 1, characterized in that: The monitoring module includes a switch circuit and / or a sensor circuit; The switch circuit comprises a switch button S1, one end of the switch button S1 is connected to the power supply voltage VCC, and the other end of the switch button S1 is connected to the DONE pin of the watchdog chip; The sensing circuit includes a sensor U1 having a transmitting unit and a receiving unit, one end of the transmitting unit is connected to the power supply voltage VCC through a resistor R1, and the other end of the transmitting unit is grounded, one end of the receiving unit is connected to the power supply voltage VCC, and the other end of the receiving unit is divided into two paths, one is connected to the ground through a resistor R2, and the other is connected to the DONE pin of the watchdog chip.

3. The hardware watchdog circuit for use in a timeout monitoring scenario according to claim 2, characterized in that: The sensor U1 is a slot-type optical coupler sensor.

4. The hardware watchdog circuit for use in a timeout monitoring scenario according to claim 1, characterized in that: The alarm module includes resistor R3, resistor R4, resistor R5, transistor Q1 and an alarm, the collector of the transistor Q1 is connected to the power supply voltage VCC via the resistor R3, the base of the transistor Q1 is connected to the RSTn pin of the watchdog chip via the resistor R4, the two ends of the resistor R5 are respectively connected to the power supply voltage VCC and the RSTn pin of the watchdog chip, and the two ends of the alarm are respectively connected to the emitter of the transistor Q1 and the ground.

5. The hardware watchdog circuit for use in a timeout monitoring scenario according to claim 4, characterized in that: The alarm is a light alarm, a sound alarm or a sound and light alarm circuit.

6. The hardware watchdog circuit used in a timeout monitoring scenario according to any one of claims 1 to 5, characterized in that: The maximum feeding time interval of the watchdog chip is 100ms~7200s.

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