CN218920408U - TTL communication port level conversion system of gas meter - Google Patents
TTL communication port level conversion system of gas meter Download PDFInfo
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- CN218920408U CN218920408U CN202222854766.9U CN202222854766U CN218920408U CN 218920408 U CN218920408 U CN 218920408U CN 202222854766 U CN202222854766 U CN 202222854766U CN 218920408 U CN218920408 U CN 218920408U
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Abstract
The utility model provides a fuel gas meter TTL communication port level conversion system, which comprises a battery module, a first communication module, a second communication module, a first level conversion module and a second level conversion module, wherein the battery module is connected with the first communication module and is used for supplying power to a fuel gas meter circuit system; the first communication module is connected with the second communication module and is used for outputting signals to the second communication module and receiving signals output by the second communication module; the second communication module is used for outputting signals to the first communication module and receiving signals output by the first communication module; the first level conversion module is respectively connected with the first communication module and the second communication module and is used for converting low level transmitted by the second communication module into high level and inputting the high level to the first communication module; the second level conversion module is respectively connected with the first communication module and the second communication module and is used for converting the high level output by the first communication module into the low level and inputting the low level to the second communication module.
Description
Technical Field
The utility model belongs to the field of TTL communication of intelligent natural gas meters, and particularly relates to a level conversion system of a TTL communication port of a gas meter.
Background
Along with the rapid development of the internet of things technology, the natural gas intelligent gas meter becomes an indispensable part in modern urban life, and the internet of things communication equipment for tracking and controlling the data of the natural gas intelligent gas meter is also various.
The method is characterized in that various Internet of things communication modules are to be adapted to the existing gas meter, and the electrical parameters of each Internet of things communication module are different, so that the phenomenon that communication data are abnormal or burnt due to the fact that the level of a TTL communication port between the gas meter and the Internet of things communication module is not matched is likely to occur; the gas meter controller requires low power consumption, has limited controller board layout space and civilian products, effectively controls cost, and ensures a level conversion effect with strong driving capability, so that a scheme of using a finished voltage conversion chip is eliminated; in the prior art, the serial port of the MCU controller is directly connected to the serial port of the external control device, if the level of the TTL communication port of the external control device is not matched with the level of the MCU controller, the phenomenon that the device port burns out due to the too high level or communication data is abnormal due to the too low level can occur in the working process of TTL communication.
Disclosure of Invention
Aiming at the defects in the prior art, the utility model aims to provide a fuel gas meter TTL communication port level conversion system which solves the problems in the prior art.
In order to solve the technical problems, the utility model adopts the following technical scheme:
the fuel gas meter TTL communication port level conversion system comprises a battery module, a first communication module, a second communication module, a first level conversion module and a second level conversion module,
the battery module is connected with the first communication module and is used for supplying power to the gas meter circuit system;
the first communication module is connected with the second communication module and is used for outputting signals to the second communication module and receiving signals output by the second communication module;
the second communication module is used for outputting signals to the first communication module and receiving signals output by the first communication module;
the first level conversion module is respectively connected with the first communication module and the second communication module and is used for converting low level transmitted by the second communication module into high level and inputting the high level to the first communication module;
the second level conversion module is respectively connected with the first communication module and the second communication module and is used for converting the high level output by the first communication module into the low level and inputting the low level to the second communication module.
Preferably, the first communication module is an MCU controller U2, the second communication module is an external control device U3, the second level conversion module includes a second triode Q2 and a resistor R3, an emitter E end of the second triode Q2 is connected with an mcu_txd transmitting end of the MCU controller U2, a collector C end of the second triode Q2 is connected with the resistor R3 and a ured receiving end of the external control device U3 respectively, a base B end of the second triode Q2 is connected with a vdd_exd output end of the external control device U3, and another end of the resistor R3 is connected with a vdd_exd output end of the external control device U3.
Preferably, the second level conversion module further includes a resistor R4, and two ends of the resistor R4 are respectively connected with the base B end of the collector of the second triode Q2 and the vdd_exd output end of the external control device U3.
Preferably, the first level conversion module includes a first triode Q1 and a resistor R1, an emitter E end of the first triode Q1 is connected with a UTXD transmitting end of the external control device U3, a collector C end of the first triode Q1 is connected with the resistor R1 and an mcu_rxd receiving end of the MCU controller U2, a base B end of the first triode Q1 is connected with a vdd_exd output end of the external control device U3, and the other end of the resistor R1 is connected with an output VCC of the MCU controller U2.
Preferably, the first level conversion module further includes a resistor R2, and two ends of the resistor R2 are respectively connected with the base B end of the first triode Q1 and the vdd_exd output end of the external control device U3.
Preferably, the battery module includes a power source J1, a diode D1 and a voltage stabilizing chip U1, one end of the power source J1 is connected with the diode D1, the other end is connected to the ground GND, the other end of the diode D1 is connected with an input end VDD of the voltage stabilizer U1, an output end OUT of the voltage stabilizer U1 is connected with an output VCC of the MCU controller U2, and the GND of the voltage stabilizer U1 is grounded.
Compared with the prior art, the utility model has the following technical effects:
according to the level conversion system of the TTL communication port of the gas meter, data is sent to the second communication module through the second level conversion module through the sending port of the first communication module, namely the second communication module receives the data sent by the first communication module through the second level conversion; in addition, the second communication module sends data to the first communication module through the first level conversion module, namely, a receiving port of the first communication module receives the data sent by the second communication module through the first level conversion module; the voltage matching effect between the high level and the low level of the first communication module and the second communication module is ensured, and the phenomenon of equipment damage or abnormal communication caused by the direct port connection work of TTL communication of equipment on two sides is effectively prevented;
the gas meter TTL communication port level conversion system has the advantages of simple circuit, flexible power supply, wide application range, high maintainability and low cost, and can meet the power supply environment of the gas meter.
Drawings
FIG. 1 is a circuit diagram of a TTL communication port level conversion system of a gas meter according to the utility model;
FIG. 2 is a block diagram of the overall fuel gas meter TTL communication port level conversion system of the present utility model.
The following examples illustrate the utility model in further detail.
Detailed Description
The following specific embodiments of the present utility model are provided, and it should be noted that the present utility model is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solutions of the present application fall within the protection scope of the present utility model.
Examples:
the fuel gas meter TTL communication port level conversion system comprises a battery module, a first communication module, a second communication module, a first level conversion module and a second level conversion module,
the battery module is connected with the first communication module and is used for supplying power to the gas meter circuit system;
the first communication module is connected with the second communication module and is used for outputting signals to the second communication module and receiving signals output by the second communication module;
the second communication module is used for outputting signals to the first communication module and receiving signals output by the first communication module;
the first level conversion module is respectively connected with the first communication module and the second communication module and is used for converting low level transmitted by the second communication module into high level and inputting the high level to the first communication module;
the second level conversion module is respectively connected with the first communication module and the second communication module and is used for converting the high level output by the first communication module into the low level and inputting the low level to the second communication module.
In the fuel gas meter TTL communication port level conversion system of this embodiment, data is sent to the second communication module through the second level conversion module by the sending port of the first communication module, that is, the second communication module receives the data sent from the first communication module through the second level conversion; in addition, the second communication module sends data to the first communication module through the first level conversion module, namely, a receiving port of the first communication module receives the data sent by the second communication module through the first level conversion module; the voltage matching effect between the high level and the low level of the first communication module and the second communication module is guaranteed, and the phenomenon that equipment is damaged or communication is abnormal when the equipment on two sides directly performs port connection work of TTL communication is effectively prevented.
As a preferable scheme of the embodiment, the first communication module is an MCU controller U2, the second communication module is an external control device U3, the second level conversion module comprises a second triode Q2 and a resistor R3, an emitter E end of the second triode Q2 is connected with an MCU_TXD transmitting end of the MCU controller U2, a collector C end of the second triode Q2 is respectively connected with the resistor R3 and a URXD receiving end of the external control device U3, a base B end of the second triode Q2 is connected with a VDD_EXD output end of the external control device U3, and the other end of the resistor R3 is connected with a VDD_EXD output end of the external control device U3.
The MCU controller U2 and the external control equipment U3 are used for realizing communication between the gas meter and the external setting, and the second triode Q2 is turned on at a low level and turned off at a high level; the second transistor Q2 used in this embodiment is turned off at a voltage greater than 0.7V and turned on at a voltage less than 0.7V.
When the transmitting end MCU_TXD end of the TTL communication serial port of the MCU controller U2 transmits high level 3.6V, namely the level of the emitter E end of the second triode Q2 is high level 3.6V, the second triode Q2 is cut off, and the receiving end URXD end of the TTL communication serial port of the external control equipment U2 is pulled up to the voltage 1.8V of VDD_EXD output by the external control equipment U2 through the third resistor R3, so that the received level is matched with the voltage level of the system of the external control equipment U2 and is 1.8V, the purpose of converting the high level of the first communication module and the high level of the second communication module into the low level is realized, the stability of converting the level matching is ensured, and the problem of damage caused by overhigh voltage received by the external control equipment U3 is prevented.
When the transmitting end MCU_TXD end of the TTL communication serial port of the MCU controller U2 transmits low electric level 0V, namely the electric level of the emitter E end of the second triode Q2 is low level 0V, and the second triode Q2 is conducted, the collector C end and the emitter E end of the second triode Q2 are equal to 0V, namely the received voltage of the receiving end URXD of the TTL communication serial port of the external control equipment U2 is 0V; the method greatly ensures that the level sent by the MCU controller U2 is the same as the level receivable by the external control equipment U3, and ensures the stability of conversion level matching.
In this embodiment, the output level of the TTL communication serial port of the MCU controller is 3.6v, and the model of the MCU controller is: R7F0C019l, TTL communication serial port receiving level of the external control equipment U3 is 1.8V; the external control device U3 is: BC25, triode Q2 is NPN transistor, withstand voltage 40V; the pull-up resistor R3 has a resistance of 10K and a pull-up voltage VDD_EXD of 1.8V.
As a preferred solution of this embodiment, the second level conversion module further includes a resistor R4, and two ends of the resistor R4 are respectively connected to the collector base B end of the second triode Q2 and the vdd_exd output end of the external control device U3.
In this embodiment, the resistor R4 is an overcurrent resistor, so as to prevent the second triode Q2 from being burned out due to excessive current, and the resistance value of the resistor R4 is 5.1K.
As a preferred solution of this embodiment, the first level conversion module includes a first triode Q1 and a resistor R1, an emitter E end of the first triode Q1 is connected to a UTXD transmitting end of the external control device U3, a collector C end of the first triode Q1 is connected to the resistor R1 and an mcu_rxd receiving end of the MCU controller U2, a base B end of the first triode Q1 is connected to a vdd_exd output end of the external control device U3, and the other end of the resistor R1 is connected to an output VCC of the MCU controller U2.
When the transmitting end UTXD end of the TTL communication serial port of the external control device U3 transmits 1.8V, that is, the level of the emitter E end of the first triode Q1 is 1.8V, that is, the first triode Q1 is turned off, because the receiving end mcu_rxd end of the TTL communication serial port of the MCU controller U2 is pulled up to the output end VCC of the power module by the first resistor R1 to be 3.6V, that is, the level received by the MCU controller U2 is matched with the self system voltage level, that is, to be 3.6V, the purpose of converting the low level of the first communication module and the low level of the second communication module into the high level is achieved, the stability of converting the level matching is ensured, and the problem of communication abnormality caused by the fact that the MCU controller receives the voltage too low is prevented;
when the transmitting MCU_TXD end of the TTL communication serial port of the external control equipment U3 transmits low level 0V, namely the level of the emitter E end of the first triode Q1 is 0V, the first triode Q1 is conducted, and at the moment, the collector C end and the emitter E end of the first triode Q1 are equal to 0V, namely the received voltage of the receiving end MCU_RXD of the TTL communication serial port of the MCU controller U2 is 0V; the method has the advantages that the level sent by the external control equipment U3 is greatly guaranteed to be the same as the level receivable by the MCU controller, the stability of level matching is guaranteed, and the problem of communication abnormality caused by too low voltage received by the MCU controller is prevented;
in this embodiment, the TTL communication serial port output level of the external control device U3 is 1.8V; the TTL communication serial port receiving level of the MCU controller is 3.6V; the triode is an NPN transistor, and has a withstand voltage of 40V; the first pull-up resistor R1 is 10K and the pull-up voltage VCC is 3.6V.
As a preferred solution of this embodiment, the first level conversion module further includes a resistor R2, and two ends of the resistor R2 are respectively connected to the base B end of the first triode Q1 and the vdd_exd output end of the external control device U3.
The resistor R2 is a current limiting resistor, so as to prevent the first triode Q1 from being burnt out due to excessive current, and the resistance value of the resistor R2 is as follows: 5.1K.
As a preferred solution of this embodiment, the battery module includes a power source J1, a diode D1 and a voltage stabilizing chip U1, where one end of the power source J1 is connected to the diode D1, the other end is connected to the ground GND, the other end of the diode D1 is connected to the input terminal VDD of the voltage regulator U1, the output terminal OUT of the voltage regulator U1 is connected to the output VCC of the MCU controller U2, and the GND of the voltage regulator U1 is grounded
Wherein, power battery is 6V, and diode D1's effect is: positive and negative voltage isolation, model is: 1N4007, the voltage regulator U1 is. ME6210A36PG was regulated to 3.6V.
Claims (6)
1. The fuel gas meter TTL communication port level conversion system, the battery module, the first communication module and the second communication module are characterized by also comprising a first level conversion module and a second level conversion module,
the battery module is connected with the first communication module and is used for supplying power to the gas meter circuit system;
the first communication module is connected with the second communication module and is used for outputting signals to the second communication module and receiving signals output by the second communication module;
the second communication module is used for outputting signals to the first communication module and receiving signals output by the first communication module;
the first level conversion module is respectively connected with the first communication module and the second communication module and is used for converting low level transmitted by the second communication module into high level and inputting the high level to the first communication module;
the second level conversion module is respectively connected with the first communication module and the second communication module and is used for converting the high level output by the first communication module into the low level and inputting the low level to the second communication module.
2. The system of claim 1, wherein the first communication module is an MCU controller U2, the second communication module is an external control device U3, the second level conversion module includes a second triode Q2 and a resistor R3, an emitter E of the second triode Q2 is connected to an mcu_txd transmitting end of the MCU controller U2, a collector C of the second triode Q2 is connected to the resistor R3 and a URXD receiving end of the external control device U3, a base B of the second triode Q2 is connected to a vdd_exd output end of the external control device U3, and another end of the resistor R3 is connected to a vdd_exd output end of the external control device U3.
3. The system of claim 2, wherein the second level conversion module further comprises a resistor R4, and two ends of the resistor R4 are respectively connected with the base B end of the collector of the second triode Q2 and the vdd_exd output end of the external control device U3.
4. The system of claim 2, wherein the first level conversion module comprises a first triode Q1 and a resistor R1, an emitter E of the first triode Q1 is connected with a UTXD transmitting end of the external control device U3, a collector C of the first triode Q1 is connected with the resistor R1 and an mcu_rxd receiving end of the MCU controller U2 respectively, a base B of the first triode Q1 is connected with a vdd_exd output end of the external control device U3, and the other end of the resistor R1 is connected with an output VCC of the MCU controller U2.
5. The system of claim 4, wherein the first level conversion module further comprises a resistor R2, and two ends of the resistor R2 are respectively connected with the base B end of the first triode Q1 and the vdd_exd output end of the external control device U3.
6. The system of claim 5, wherein the battery module comprises a power source J1, a diode D1 and a voltage stabilizing chip U1, one end of the power source J1 is connected with the diode D1, the other end of the power source J1 is connected to the ground GND, the other end of the diode D1 is connected with the input end VDD of the voltage stabilizer U1, the output end OUT of the voltage stabilizer U1 is connected with the output VCC of the MCU controller U2, and the GND of the voltage stabilizer U1 is grounded.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222854766.9U CN218920408U (en) | 2022-10-27 | 2022-10-27 | TTL communication port level conversion system of gas meter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222854766.9U CN218920408U (en) | 2022-10-27 | 2022-10-27 | TTL communication port level conversion system of gas meter |
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| CN218920408U true CN218920408U (en) | 2023-04-25 |
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| CN202222854766.9U Active CN218920408U (en) | 2022-10-27 | 2022-10-27 | TTL communication port level conversion system of gas meter |
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