CN201152974Y - Interface conversion circuit and digital video recorder - Google Patents
Interface conversion circuit and digital video recorder Download PDFInfo
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- CN201152974Y CN201152974Y CNU2008200916997U CN200820091699U CN201152974Y CN 201152974 Y CN201152974 Y CN 201152974Y CN U2008200916997 U CNU2008200916997 U CN U2008200916997U CN 200820091699 U CN200820091699 U CN 200820091699U CN 201152974 Y CN201152974 Y CN 201152974Y
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- 238000006243 chemical reaction Methods 0.000 title claims description 32
- 238000004891 communication Methods 0.000 claims abstract description 11
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- 230000005540 biological transmission Effects 0.000 claims description 11
- 238000000034 method Methods 0.000 abstract description 3
- 238000002955 isolation Methods 0.000 abstract 1
- 230000004888 barrier function Effects 0.000 description 4
- 238000012545 processing Methods 0.000 description 3
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Abstract
The utility model discloses an interface switching circuit and a digital video recorder, wherein, the interface switching circuit includes a switch circuit, a RS-485 interface controller and a self-adaptive circuit, wherein, the switch circuit is used for providing signal isolation and signal path selection, and is connected with an UART interface; the RS-485 interface controller is used for conducting data receiving and transmitting control process between the UART interface and the RS-485 interface by the half-duplex communication method according to control signals of the control end thereof, and is connected with the switch circuit and the RS-486 interface; the self-adaptive circuit is used for providing control singles controlling the RS-485 interface controller to automatically execute data receiving and data transmitting switch, and the output end of the self-adaptive is connected with the control end of the RS-485 interface controller. By implementing the self-adaptive switch between the RS-482 interface and the UART interface, the circuit and the recorder of the utility model solves the technical problem that at present, the interconnection between the UART interface and the RS-486 interface needs overmuch change and overhigh investment cost.
Description
Technical field
The utility model relates to the interface conversion technology, relate in particular to and a kind ofly carrying out the interface conversion circuit that interface is changed mutually between UART interface and the RS-485 interface or between UART interface and the RS-232 interface, and utilize this interface conversion circuit to realize the digital video recorder of the gps receiver of integrated belt UART interface.
Background technology
At present, great majority are realized GPS (Global Positing System, GPS) gps receiver of function is to carry out the reception and the transmission of data with universal asynchronous receiving-transmitting interface (UART, Universal Asynchronous ReceiverTransmitter).And in the electronic product of integrated gps receiver, UART interface and gps receiver that most of products directly provide by Embedded microprocessor (such as MCU) on hardware design carry out communication.
Yet some early stage electronic products of producing do not have the GPS function, as needs realize the GPS function just need external one can adaptive gps receiver.Because early stage most electronic products are only supported the RS-485 interface, usually need RS-485 interface of configuration to change the adapter of RS-232 interface when it is increased the GPS function, and then insert the UART interface of gps receiver by the RS-232 interface of adapter.This traditional solution is the cost height not only, and practical set is cumbersome.
Therefore; change for saving the cost of hardware device, and under the prerequisite of protecting electronic product as far as possible, how a kind of interface conversion circuit of development and Design; can realize the mutual conversion of RS-485 interface and UART interface, become one of technical barrier of current urgent need solution.
The utility model content
Technical problem to be solved in the utility model is the digital video recorder that proposes a kind of interface conversion circuit and use this interface conversion circuit, by realizing the mutual conversion of RS-485 interface and UART interface, having solved the interconnection of present UART interface and RS-485 interface needs to change the technical barrier excessive, that cost of investment is too high.
For solving technical matters of the present utility model, the utility model discloses a kind of interface conversion circuit, comprising:
Be used to provide the on-off circuit of Signal Spacing and signal path selection, it is connected with the UART interface;
Be used for the control signal according to its control end, make the RS-485 interface controller of data transmitting-receiving control and treatment in the half-duplex operation mode between UART interface and RS-485 interface, it connects on-off circuit and RS-485 interface;
Be used to provide control RS-485 interface controller to make the adaptive circuit of the control signal of data reception and data transmission switching automatically, its output terminal connects the control end of RS-485 interface controller.
More excellent, described adaptive circuit comprises: first, second resistor; Triode, its base stage is connected with the data sending terminal of UART interface by first resistor, and collector is connected with power supply by second resistor, and the control end of collector connection RS-485 interface controller, and grounded emitter.
More excellent, interface conversion circuit of the present utility model also comprises:
The DB9 interface;
Be used for doing in the duplex communication mode between UART interface and RS-232 interface the RS-232 interface controller of data transmitting-receiving control and treatment, described RS-232 interface controller is connected with RS-232 interface with the UART interface respectively with the DB9 interface by on-off circuit.
More excellent, described on-off circuit is a double-pole single throw.
In addition, the utility model also discloses a kind of digital video recorder, comprising: the gps receiver with UART interface; The RS-485 interface of communicating by letter as data with gps receiver; Carry out the interface conversion circuit that interface conversion is handled between UART interface and RS-485 interface, be connected between UART interface and the RS-485 interface, this interface conversion circuit comprises:
Be used to provide the on-off circuit of Signal Spacing and signal path selection, it is connected with the UART interface;
Be used for the control signal according to its control end, make the RS-485 interface controller of data transmitting-receiving control and treatment in the half-duplex operation mode between UART interface and RS-485 interface, it connects on-off circuit and RS-485 interface;
Be used to provide control RS-485 interface controller to make the adaptive circuit of the control signal of data reception and data transmission switching automatically, its output terminal connects the control end of RS-485 interface controller.
More excellent, described adaptive circuit comprises: first, second resistor; Triode, its base stage is connected with the data sending terminal of UART interface by first resistor, and collector is connected with power supply by second resistor, and the control end of collector connection RS-485 interface controller, and grounded emitter.
More excellent, digital video recorder of the present utility model also comprises: the RS-232 interface of communicating by letter as data with gps receiver; Described interface conversion circuit also comprises: the DB9 interface; Be used for doing in the duplex communication mode between UART interface and RS-232 interface the RS-232 interface controller of data transmitting-receiving control and treatment, described RS-232 interface controller is connected with RS-232 interface with the UART interface respectively with the DB9 interface by on-off circuit.
More excellent, described on-off circuit is a double-pole single throw.
Compared with prior art, the utlity model has following beneficial effect:
The utility model has solved many electronic products can not pass through the directly difficult problem of the gps receiver of outer tape splicing UART interface of RS-485 interface, has realized carrying out data communication by RS-485 interface adaptive and UART interface.The utility model is concentrated the technical barrier that has solved interface conversion between RS-232 interface and RS-485 interface and the UART interface simultaneously.Therefore, use interface conversion circuit of the present utility model that electronic product is made upgrading processing, not only save the cost of changing hardware device, also protect electronic product as much as possible, reduced change electronic product.
Description of drawings
Fig. 1 is the structural representation of a preferred embodiment of the utility model;
Fig. 2 is the sequential synoptic diagram of transmission signals in preferred embodiment of the utility model.
Embodiment
The utility model considers that most gps receivers only have the UART interface, and early stage many electronic products of producing only provide RS-232 interface or RS-485 interface usually; Realize the GPS function as need in these electronic products, then needing the UART interface conversion with gps receiver is RS-232 interface or RS-485 interface.And, because in RS-232 interface definition, receive data and send data by two independently circuit (RX and TX) realize, be the more or less freely realization of RS-232 interface therefore with the UART interface conversion; And the RS-485 interface definition is differential signal, the selection that receives data and transmission data needs an other control line to finish, and general electronic product accepted standard RS-485 interface is not have this signal wire, therefore, how to realize that the adaptation function that the RS-485 interface data is received and dispatched becomes key of the present utility model.
With reference to shown in Figure 1, present embodiment can be that electronic product is improved, and integrated gps receiver is realized the GPS function, to satisfy the customer requirements that electronic product increases day by day.Such as, (Digital Video Recorder DVR) transforms gps receiver with the integrated UART of having interface to vehicle-mounted digital video cassette recorder with RS-232 interface or RS-485 interface.
Present embodiment comprises: the gps receiver 110 with UART interface 111; The on-off circuit 121 that provides Signal Spacing and signal path to select, it is connected with UART interface 111; Be used for the control signal according to two control end RE and DE, make the RS-485 interface controller 122 of data transmitting-receiving control and treatment in the half-duplex operation mode between UART interface 111 and RS-485 interface 130, it connects on-off circuit 121 and RS-485 interface 130; Be used to provide control RS-485 interface controller 122 to do automatically that data receive and data send the adaptive circuit 123 of the control signal of switching, two control end RE of its output terminal connection RS-485 interface controller 122 and DE.
For increasing applicability of the present utility model, present embodiment is also integrated with the function of RS-232 interface 140 with 111 conversions of UART interface, it mainly by the RS-232 interface controller 124 of making data transmitting-receiving control and treatment in the duplex communication mode between UART interface 111 and RS-232 interface 140, is connected with RS-232 interface 140 with UART interface 111 respectively with DB9 interface 125 by on-off circuit 121.
Wherein, RS-232 interface controller 124 receives the data that send by on-off circuit 121 from the data sending terminal TXD of UART interface 111 by data receiver TXD, by exporting from data receiver RX after RS-232 interface controller 124 switching levels, export RS-232 interface 140 to through DB9 interface 125; And another data receiver TX receives the data of RS-232 interface 140 through 125 transmission of DB9 interface, by the data receiver RXD that sends to UART interface 111 after RS-232 interface controller 124 switching levels by another data receiver RXD by on-off circuit 121.
And the data receiver DI of RS-485 interface controller 122 is used to receive the data of the data sending terminal TXD of UART interface 111 by on-off circuit 121 transmissions, and data sending terminal RO is used for sending data to by on-off circuit 121 the data receiver RXD of UART interface 111; And, the direction control that sends data and reception data is realized by the control signal on two control end RE and the DE: when control end RE is low level, the data that RS-485 interface controller 122 receives from RS-485 interface 130, and after doing the switching levels processing, send the data to the data receiver RXD of UART interface 111 by on-off circuit 121; When control end DE was high level, RS-485 interface controller 122 passed through the data sending terminal TXD reception data of on-off circuit 121 from UART interface 111, and does to send to RS-485 interface 130 after switching levels is handled.
Consider that RS-485 interface 130 itself only supported the half-duplex mode communication, that is to say, at synchronization, RS-485 interface controller 122 can only receive data or send data, and the control of reception data and transmission data will be controlled by two control end RE and DE; For the automatic switchover that realizes receiving data and send data, so present embodiment has increased adaptive circuit 123.
This adaptive circuit 123 comprises: first, second resistor R 1 and R2; Triode Q1, its base stage (B) is connected with the data sending terminal TXD of UART interface 111 by first resistor R 1, collector (C) is connected with power supply by second resistor R 2, and two control end RE of collector connection RS-485 interface controller 122 and DE, and emitter (E) ground connection.
And, definition according to the RS-485 interface specification, when the data receiver DI of RS-485 interface controller 122 goes up no datat (gps receiver 110 does not outwards send data), data receiver DI is a high level, cause triode Q1 to be in conducting state, two control end RE and DE are low level, make RS-485 interface controller 122 be in the reception data mode; When data occurring on the data receiver DI (gps receiver 110 outwards send data), the level state of two control end RE and DE will be done reverse variation along with data receiver DI goes up level state, with reference to sequential chart shown in Figure 2.
This shows, by the differential signal of output on RS-485 interface controller 122 I/O end A and the B and the waveform of the input signal on the data receiver DI is basically identical, the signal variation that deviation comes from control end DE always postpones a little than the signal of data receiver DI, this depends on the response speed with triode Q1, therefore, can adopt reaction velocity faster triode Q1 improve as much as possible according to receiving end DI and control end DE signal synchronously.Thus, do not having under the situation of extra control port, RS-485 interface controller 122 has realized receiving the adaptation function of data and transmission data.
Preferably, in the present embodiment, on-off circuit 121 adopts double-pole single throw.When communicating by RS-232 interface 140 and gps receiver 110, need the communication path of selecting RS-232 interface 140 to communicate by letter with UART interface 111, double-pole single throw is allocated to UART interface 111 is connected with RS-232 interface controller 124.Equally, when communicating by RS-485 interface 130 and gps receiver 110, need be allocated to double-pole single throw UART interface 111 is connected with RS-485 interface controller 122.
To sum up, the utlity model has following useful technique effect:
The utility model has solved many electronic products can not pass through the directly difficult problem of the gps receiver of outer tape splicing UART interface of RS-485 interface, has realized carrying out data communication by RS-485 interface adaptive and UART interface.The utility model is concentrated the technical barrier that has solved interface conversion between RS-232 interface and RS-485 interface and the UART interface simultaneously.Therefore, use interface conversion circuit of the present utility model that electronic product is made upgrading processing, not only save the cost of changing hardware device, also protect electronic product as much as possible, reduced change electronic product.
Claims (8)
1, a kind of interface conversion circuit is characterized in that, comprising:
Be used to provide the on-off circuit of Signal Spacing and signal path selection, it is connected with the UART interface;
Be used for the control signal according to its control end, make the RS-485 interface controller of data transmitting-receiving control and treatment in the half-duplex operation mode between UART interface and RS-485 interface, it connects on-off circuit and RS-485 interface;
Be used to provide control RS-485 interface controller to make the adaptive circuit of the control signal of data reception and data transmission switching automatically, its output terminal connects the control end of RS-485 interface controller.
2, interface conversion circuit according to claim 1 is characterized in that, described adaptive circuit comprises: first, second resistor; Triode, its base stage is connected with the data sending terminal of UART interface by first resistor, and collector is connected with power supply by second resistor, and the control end of collector connection RS-485 interface controller, and grounded emitter.
3, interface conversion circuit according to claim 1 is characterized in that, also comprises:
The DB9 interface;
Be used for doing in the duplex communication mode between UART interface and RS-232 interface the RS-232 interface controller of data transmitting-receiving control and treatment, described RS-232 interface controller is connected with RS-232 interface with the UART interface respectively with the DB9 interface by on-off circuit.
According to claim 1 or 2 or 3 described interface conversion circuits, it is characterized in that 4, described on-off circuit is a double-pole single throw.
5, a kind of digital video recorder is characterized in that, comprising: the gps receiver with UART interface; The RS-485 interface of communicating by letter as data with gps receiver; Carry out the interface conversion circuit that interface conversion is handled between UART interface and RS-485 interface, be connected between UART interface and the RS-485 interface, this interface conversion circuit comprises:
Be used to provide the on-off circuit of Signal Spacing and signal path selection, it is connected with the UART interface;
Be used for the control signal according to its control end, make the RS-485 interface controller of data transmitting-receiving control and treatment in the half-duplex operation mode between UART interface and RS-485 interface, it connects on-off circuit and RS-485 interface;
Be used to provide control RS-485 interface controller to make the adaptive circuit of the control signal of data reception and data transmission switching automatically, its output terminal connects the control end of RS-485 interface controller.
6, digital video recorder according to claim 5 is characterized in that, described adaptive circuit comprises: first, second resistor; Triode, its base stage is connected with the data sending terminal of UART interface by first resistor, and collector is connected with power supply by second resistor, and the control end of collector connection RS-485 interface controller, and grounded emitter.
7, digital video recorder according to claim 5 is characterized in that, also comprises: the RS-232 interface of communicating by letter as data with gps receiver;
Described interface conversion circuit also comprises:
The DB9 interface;
Be used for doing in the duplex communication mode between UART interface and RS-232 interface the RS-232 interface controller of data transmitting-receiving control and treatment, described RS-232 interface controller is connected with RS-232 interface with the UART interface respectively with the DB9 interface by on-off circuit.
According to claim 5 or 6 or 7 described digital video recorders, it is characterized in that 8, described on-off circuit is a double-pole single throw.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200916997U CN201152974Y (en) | 2008-01-18 | 2008-01-18 | Interface conversion circuit and digital video recorder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200916997U CN201152974Y (en) | 2008-01-18 | 2008-01-18 | Interface conversion circuit and digital video recorder |
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| Publication Number | Publication Date |
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| CN201152974Y true CN201152974Y (en) | 2008-11-19 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNU2008200916997U Expired - Fee Related CN201152974Y (en) | 2008-01-18 | 2008-01-18 | Interface conversion circuit and digital video recorder |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102025788A (en) * | 2010-12-03 | 2011-04-20 | 华为技术有限公司 | Communication device, communication method and communications system |
| CN103279443A (en) * | 2013-05-31 | 2013-09-04 | 成都锐奕信息技术有限公司 | Uart communication signal conversion circuit |
| CN103294629A (en) * | 2013-04-26 | 2013-09-11 | 深圳市宏电技术股份有限公司 | Interface switching circuit and device |
| CN105022711A (en) * | 2014-04-23 | 2015-11-04 | 林新辉 | serial bus communication architecture |
| CN109313621A (en) * | 2016-12-06 | 2019-02-05 | 吉蒂机器人私人有限公司 | Full-duplex and half-duplex serial port signal conversion circuit and robot |
| CN109684253A (en) * | 2017-10-19 | 2019-04-26 | 佛山市顺德区顺达电脑厂有限公司 | Data transmission control circuit |
| CN116264389A (en) * | 2023-01-31 | 2023-06-16 | 浙江双友物流器械股份有限公司 | A space electric field generator |
| CN116483759A (en) * | 2023-04-28 | 2023-07-25 | 深圳市兴源智能仪表股份有限公司 | An interface conversion circuit, method and chip |
-
2008
- 2008-01-18 CN CNU2008200916997U patent/CN201152974Y/en not_active Expired - Fee Related
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102025788A (en) * | 2010-12-03 | 2011-04-20 | 华为技术有限公司 | Communication device, communication method and communications system |
| WO2012072052A1 (en) * | 2010-12-03 | 2012-06-07 | 华为技术有限公司 | Communication device, method and system |
| CN103294629A (en) * | 2013-04-26 | 2013-09-11 | 深圳市宏电技术股份有限公司 | Interface switching circuit and device |
| CN103294629B (en) * | 2013-04-26 | 2016-08-10 | 深圳市宏电技术股份有限公司 | A kind of interface conversion circuit and device |
| CN103279443A (en) * | 2013-05-31 | 2013-09-04 | 成都锐奕信息技术有限公司 | Uart communication signal conversion circuit |
| CN105022711A (en) * | 2014-04-23 | 2015-11-04 | 林新辉 | serial bus communication architecture |
| CN109313621A (en) * | 2016-12-06 | 2019-02-05 | 吉蒂机器人私人有限公司 | Full-duplex and half-duplex serial port signal conversion circuit and robot |
| CN109313621B (en) * | 2016-12-06 | 2022-05-24 | 吉蒂机器人私人有限公司 | Full-duplex and half-duplex serial port signal conversion circuit and robot |
| CN109684253A (en) * | 2017-10-19 | 2019-04-26 | 佛山市顺德区顺达电脑厂有限公司 | Data transmission control circuit |
| CN116264389A (en) * | 2023-01-31 | 2023-06-16 | 浙江双友物流器械股份有限公司 | A space electric field generator |
| CN116483759A (en) * | 2023-04-28 | 2023-07-25 | 深圳市兴源智能仪表股份有限公司 | An interface conversion circuit, method and chip |
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