CN112925681A - Timing detection circuit of vehicle-mounted split type touch screen - Google Patents
Timing detection circuit of vehicle-mounted split type touch screen Download PDFInfo
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Abstract
A timing detection circuit of a vehicle-mounted split type touch screen comprises a CPU module, a touch screen controller, a serializer and a deserializer, wherein data transmission is realized between the CPU module and the touch screen controller through the serializer and the deserializer; the system also comprises a first switching module, a second switching module, a power supply module and a signal generating module; the first switching module is connected with the power supply module and the touch screen controller; the second switching module is connected between the deserializer and the touch screen controller; the signal generator and the power supply module are used for generating fixed frequency when power supply is switched on; the touch screen controller is connected with the signal generator; the CPU module judges the working state of the touch screen according to the waveform signal and outputs a corresponding control signal to be transmitted to the deserializer; the deserializer is also connected with the first switching module to control the states of the first switching module and the second switching module according to the control signal. The circuit of the invention has simple structure, easy realization, low cost and strong universality.
Description
Technical Field
The invention relates to the field of vehicle-mounted equipment, in particular to a timing detection circuit of a vehicle-mounted split type touch screen.
Background
With the development of touch technology, touch screens are used more and more widely in the vehicle-mounted field. At present, almost all vehicle-mounted central control display screens have touch functions to realize better human-computer interaction, however, the requirements of customers on the human-computer interaction functions are continuously improved, and the application of capacitive touch screens in the vehicle-mounted field is also gradually the mainstream.
In actual application, because of the limitation of the installation size on the vehicle, when the product is designed, the touch screen can be separated from the host machine along with the split design of the central control display screen (the capacitive touch screen and the display screen are in full-lamination or frame lamination). The split design enables the central control display screen to be composed of a host controller and a remote touch display screen (comprising a capacitive touch screen and a display screen), and in order to meet the requirements of high resolution and high speed of the display screen, the communication between the host controller and the remote touch display screen is realized in a mode of an FPD-Link serializer/deserializer to carry out remote high-speed data transmission and remote control of the touch screen.
At present, a more mature scheme such as Maxim or TI adopts a twisted pair or a coaxial line between a serializer and a deserializer as a transmission medium to realize the transmission of high-speed signals and the remote control of a touch screen, so that the remote touch display screen can be far away from a host controller by more than a few meters, and is suitable for being installed in a special environment on a vehicle. In the application process, the remote touch screen is controlled by the host computer controller, in the power-on process, the deserializer of the remote touch display screen is initialized, the CPU of the host computer controller is required to configure the relevant registers, the initialization of the remote deserializer is realized in a transparent transmission mode through the serializer, and therefore the initialization of the touch screen is realized, and the remote touch screen can normally work only in this way.
However, in the vehicle-mounted application, the static test requirements for the touch screen are relatively strict, according to the relevant regulations of ISO 10605, air discharge of ± 15KV and contact discharge of ± 8KV, and under the static test environment, if the structure and the circuit of the touch screen are not properly processed, the control chip inside the touch screen fails in advance before other peripheral chips and circuits fail, and at this time, if the touch screen cannot be immediately restored, the touch screen cannot normally work for a long time. Due to the uncertainty of the static test, the failure of the control chip inside the touch screen may be partial failure or complete failure. If the host can also actively access the I2C of the touch screen, but the interrupt pin of the touch screen keeps a default pull-up state, and the touch screen is clicked, the interrupt pin has no pull-down action (in a normal situation, the interrupt pin is always high, and if the touch screen has a touch action, the interrupt pin has a pull-down action), which indicates that the touch screen has no interrupt output, the host cannot respond to the touch action, and in this situation, the host must actively access a plurality of state registers inside the touch screen at regular time to analyze and judge whether the touch screen is in an abnormal state, and then performs self-recovery, so that the I2C bus data resources are inevitably occupied (in a normal situation, when the touch screen has an interrupt signal, the host will access the I2C of the touch screen to read related data), and the difficulty and cost of software development are increased.
In addition, for static electricity testers, in the testing process, if the touch screen has functional failure, the touch screen cannot be judged whether to fail or not at all when the touch screen is not clicked, so that the trouble of the testers is increased.
Disclosure of Invention
The invention mainly aims to overcome the defects in the prior art, and provides a timing detection circuit of a vehicle-mounted split type touch screen, which is low in cost and convenient to apply.
The invention adopts the following technical scheme:
a timing detection circuit of a vehicle-mounted split type touch screen comprises a CPU module, a touch screen controller, a serializer and a deserializer, wherein data transmission is realized between the CPU module and the touch screen controller through the serializer and the deserializer; the method is characterized in that: the system also comprises a first switching module, a second switching module, a power supply module and a signal generating module; the first switching module is connected with the power supply module and the touch screen controller to control the power supply on-off of the touch screen; the second switching module is connected between the deserializer and the touch screen controller to control the on-off of signal transmission; the signal generator and the power supply module are used for generating fixed frequency when power supply is switched on; the touch screen controller is connected with the signal generation module so as to transmit the waveform signal with fixed frequency to the CPU module through the deserializer; the CPU module judges the working state of the touch screen according to the waveform signal and outputs a corresponding control signal to be transmitted to the deserializer; the deserializer is also connected with the first switching module to control the states of the first switching module and the second switching module according to the control signal.
Preferably, the touch screen controller further comprises a resistor R8 and a light emitting diode D1, wherein one end of the resistor R8 is connected with the waveform signal output end of the touch screen controller, and the other end of the resistor R8 is connected with the light emitting diode D1.
Preferably, the signal generation module comprises an active crystal oscillator, a magnetic bead, a resistor R3, a resistor R4, a capacitor C1, a capacitor C2 and a frequency division unit; one end of the magnetic bead is connected with the output end of the power supply module, and the other end of the magnetic bead is connected with one end of a resistor R3 and a capacitor C1; the other end of the resistor R3 is connected with an input end of an active crystal oscillator, the output end of the active crystal oscillator is connected with one end of a resistor R4, the other end of the resistor R4 is connected with the capacitor C2 and the input end of a frequency dividing unit, and the output end of the frequency dividing unit is connected with the touch screen controller.
Preferably, the frequency dividing unit includes a triode Q1, a resistor R6, a resistor R7 and a binary counter, a base of the triode Q1 is connected to the other end of the resistor R4, a collector is connected to one end of the resistor R7 and a CL pin of the binary counter, an emitter is connected to one end of the resistor R6, the other end of the resistor R6 is connected to an R pin of the binary counter, and an output end of the binary counter is connected to an input end of the touch screen controller.
Preferably, the first switching module comprises a switch K1, a capacitor C3 and a capacitor C4; the control end of the switch K1 is connected with the output end of the power supply module, one static end of the switch K1 is connected with one end of a capacitor C4, and the other static end of the switch K1 is connected with one end of a capacitor C3 and the power supply end of the touch screen controller.
Preferably, the second switching module comprises a switch K2, a resistor R9, a resistor R10 and a resistor R5; the control end of the switch K2 is connected with one end of a resistor R5 and the output end of the deserializer, the first moving end and the second moving end of the switch K2 are connected with two signal ends of the deserializer, a first static end is connected with one end of a resistor R9, a second static end is connected with one end of a resistor R10, and the other end of the resistor R9 and the other end of the resistor R8 are respectively connected with two signal ends of the touch screen controller.
As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following advantages:
1. the circuit is provided with a first switching module, a second switching module, a power supply module, a signal generating module and the like, the signal sending module can generate fixed frequency when the touch screen normally works, the CPU module judges the working state of the touch screen according to the detected waveform signal of the fixed frequency and outputs corresponding control signals to control the first switching module and the second switching module, the timing detection of the touch screen and the self-recovery control under the abnormal state are realized, the static test and the abnormal check are convenient, and the circuit is simple in structure, easy to realize, low in cost and high in universality.
2. The invention can reduce the extra burden of the CPU caused by the frequent detection of the CPU, and the adoption of the fixed low-frequency signal detection method can save more CPU resources compared with the mode of pure software application I2C bus communication polling, thereby reducing the software development difficulty; and the risk of electrostatic interference is reduced, and the frequency range of electrostatic noise interference is avoided.
3. The invention is matched with the use of the light-emitting diode, is convenient for the observation of the working state of the touch screen by naked eyes, and has an abnormal reminding function.
4. The invention utilizes the frequency characteristic of the active crystal oscillator, the frequency division characteristic of the binary counter and the control characteristic of the electronic analog switch; meanwhile, the timing detection of the vehicle-mounted split type touch screen, the abnormal self-recovery and abnormal reminding functions after the static test are realized by adopting the detection control technology of the I/O port and the transparent transmission control technology of the FPD-Link serializer/deserializer.
5. The circuit is practically applied to a vehicle-mounted remote touch screen with a host and a touch screen separated from each other, and is used for solving the problem that the remote touch screen fails to work and the touch control cannot be normally recovered; the static test device is convenient for relevant testers to carry out static test experiments of the remote touch screen and touch screen self-checking and troubleshooting in daily use.
Drawings
FIG. 1 is a block diagram of the present invention;
FIG. 2 is a flow chart of the present invention.
Detailed Description
The invention is further described below by means of specific embodiments.
Referring to fig. 1, a timing detection circuit of a vehicle-mounted split touch screen includes a CPU module, a touch screen controller, a serializer, a deserializer, a first switching module, a second switching module, a power supply module, a signal generation module, and the like. The CPU module and the touch screen controller realize data transmission through the serializer and the deserializer.
The first switching module is connected with the power supply module and the touch screen controller to control the power supply on-off of the touch screen, and the first switching module can be realized by adopting a single-pole double-throw switch or an MOS (metal oxide semiconductor) tube or a relay and the like.
Specifically, the first switching module includes a switch K1, a capacitor C3, and a capacitor C4. The control end of the switch K1 is connected to an output end VOUT1 of the power supply module, a static end of the switch is connected to one end of a capacitor C4, the other end of the switch is connected to one end of a capacitor C3 and a VCC end of the touch screen controller, i.e., a power supply end, and the other ends of the capacitor C3 and the capacitor C4 are grounded. The internal default state of the switch K1 is that the moving terminal A1 is connected to a static terminal B1. The default of the control terminal S1 is low, the control terminal S1 is connected to the GPIO5_ REG port of the power supply module U4, and the pin C1 of the KI is connected to the power supply terminal VCC3.3 of the touch screen controller U5. The capacitor C3 and the capacitor C4 are power filter capacitors.
The second switching module is connected between the deserializer and the touch screen controller to control the on-off of signal transmission. The first switching module may be implemented using a double-pole double-throw switch or an analog switch (e.g., SGM 3002).
The second switching module includes a switch K2, a resistor R9, a resistor R10, and a resistor R5. The control end of the switch K2 is connected with one end of a resistor R5 and the output end of the deserializer, the first moving end and the second moving end of the switch K2 are connected with two signal ends of the deserializer, a first static end is connected with one end of a resistor R9, a second static end is connected with one end of a resistor R10, and the other end of the resistor R9 and the other end of the resistor R10 are respectively connected with two signal ends of the touch screen controller. R5 is a pull-down resistor, which ensures that GPIO5_ REG of the power-up instant deserializer U4 is low.
Referring to the double-pole double-throw switch of fig. 1, the control terminal S is default low, the control terminal S is connected to the GPIO5_ REG port of the deserializer U4, the first moving terminal D is connected to a first static terminal D1 in its default state, and the first moving terminal D is connected to the clock signal SCL of I2C of the deserializer U4. The other first dead end D2 is connected to the clock signal SCL1 pin of I2C of the touch screen controller U5 through the resistor R9.
The second moving terminal E is connected to a second dead terminal E1, and the second dead terminal E is connected to the data signal SDA of I2C of the deserializer U4. The other second dead end E2 is connected to the data signal SDA1 pin of I2C of U5 through R10. The switch K2 is added for controlling to prevent the problem that the normal reset cannot be caused by the serial connection of the I2C of the deserializer U4 to the U5 in the reset power-off process of the touch screen controller U5. And a pull-up resistor corresponding to I2C, which is not shown. The resistor R9 and the resistor R10 are matched resistors, so that the overshoot of the I2C signal is reduced, and the value is generally 22 ohms.
The signal generator and the power supply module are used for generating a fixed frequency when power supply is switched on and comprise an active crystal oscillator, a magnetic bead, a resistor R3, a resistor R4, a capacitor C1, a capacitor C2, a frequency dividing unit and the like. One end of the magnetic bead L1 is connected with the other output end VOUT2 of the power supply module, the other end of the magnetic bead L1 is connected with one end of the resistor R3 and the capacitor C1, and the magnetic bead L1 is used for eliminating high-frequency interference. The other end of the resistor R3 is connected with an active crystal oscillator input end, the active crystal oscillator output end is connected with one end of a resistor R4, and the active crystal oscillator Y1 outputs a fixed frequency F1 which can be 32.768KHZ in practice. The other end of the resistor R4 is connected with the capacitor C2 and the input end of the frequency dividing unit, and the output end of the frequency dividing unit is connected with the touch screen controller. Wherein, R4 is a matching resistor, the capacitor C2 is a high-frequency filter capacitor, R3 is a current-limiting resistor, and the capacitor C1 is a power filter capacitor.
The frequency dividing unit comprises a triode Q1, a resistor R6, a resistor R7 and a binary counter, wherein the base electrode of the triode Q1 is connected with the other end of the resistor R4, the collector electrode of the triode Q1 is connected with one end of a resistor R7 and the CL pin of the binary counter, the emitter electrode of the triode Q1 is connected with one end of a resistor R6, the other end of the resistor R6 is connected with the R pin of the binary counter, and the output end of the binary counter is connected with the input end of the touch screen. U7 is a binary counter, such as CD4020BE in practical application, to realize frequency division function.
The waveform with the frequency of F1 output by the active crystal oscillator Y1 is set, the waveform is F2 after the frequency division is carried out through U7, the frequency of F2 is required to be less than 20HZ (because the human eye has the frequency of more than 50HZ, the flicker can not be distinguished, meanwhile, in order to avoid the audio signal range 20HZ-20KHZ which can be distinguished by human ears and prevent the audio interference from being generated), low-frequency signals are adopted, the CPU load caused by frequent detection is reduced, and the risk of electrostatic interference is reduced, and the electrostatic interference belongs to the high-frequency signal interference; in practice, F2 is as small as possible, such as 2 HZ.
A pin R of U7 is a clearing end, the grounding is effective through a resistor R6, and a pin CL of U7 is a clock input end; q1, Q2 to Qn are counter pulse outputs (n represents an n-bit binary counter, which can be implemented as 2)nFrequency division). The resistor R7 is a pull-up resistor, which is pulled up to VCC2, typically 3.3V, and the Q1 is an NPN transistor.
The touch screen controller U5 is connected to a signal generator to transmit a fixed frequency waveform signal through a deserializer to the CPU module. The touch screen controller U5 is a control IC of the touch screen, and in practical applications, such as ATMXT1189T, when the touch screen is customized, it can be selected as required.
The CPU module U1 determines the operating state of the touch screen according to the waveform signal, and outputs a corresponding control signal to the deserializer. The U1 is a core system module, which comprises a CPU, a DDR3, an EMMC, a PMIC and the like inside, has an audio and video coding and decoding function, comprises a dual-path LVDS interface, an HDMI interface, an MIPI interface and a combined circuit comprising WIFI, Bluetooth, GPS and the like, and actually operates under an android platform, I/O1; I/O2 is an internal GPIO port of U1, and I/O1 and I/O2 are configured as input ports. One ends of input ports I/O1 and I/O2 of the CPU module U1 are respectively connected with pull-up resistors R1 and R2, and pull-up resistors R1 and R2 are respectively connected with VCC1 and VCC 2. I/O1, I/O2 of U1 defaults to high.
The serializer U2 may employ FPD-Link serializers (such as DS90UB949Q-Q1 of TI), the CPU module U1 and serializer U2 internally performing I2C communication and HDMI signal communication; during power-on initialization, the CPU module U1 configures related registers through the I2C, configures GPIO1 and GPIO2 ports of the serializer U2 as output ports respectively, and is connected with I/O1 and I/O2 of the CPU module U1 respectively.
The deserializer U4 is also connected to the first switching module to control the state of the first and second switching modules according to the control signal. The deserializer can be an FPD-Link deserializer (such as DS90UB948Q-Q1 of TI), and the touch screen controller U5 can be a touch screen control chip. The deserializer U4 and the touch screen controller U5 communicate through I2C, the input pin GPIO2 of U4 is connected to the interrupt output pin INT of U5, the output pin GPIO6_ REG of U4 is connected to the reset pin RST of U5, and the input pin GPIO1 of U4 is connected to the output pin I/O _1 of U5.
The invention also comprises a resistor R8 and a light-emitting diode D1, wherein one end of the resistor R8 is connected with an output pin I/O _1 of the touch screen controller, the other end of the resistor R8 is connected with the anode of the light-emitting diode D1, and the cathode of the light-emitting diode D1 is grounded. R8 is a current limiting resistor.
The power supply module U6 of the present invention is a power supply module of a remote touch screen, and may include DCDC and LDO, which may be powered by the DC-DC module U3 at the end of the CPU module U1, and the DC-DC module U3 may output 12V voltage. The power supply module U6 includes an input terminal VIN and two output terminals VOUT1, VOUT 2.
And AB represents a connecting line of the host and the remote touch screen, and the inside of the connecting line is a twisted pair line which comprises a required differential signal line, a required power line and a required ground line. The VOUT of the DC-DC module is generally 12V, is connected to a power supply input end VIN of a power supply module U6 through an AB line, is converted into VOUT1 through a power supply module U6 and is controlled by a switch K1 to provide power for a touch screen controller U5, and meanwhile, a power supply VOUT2 supplies power for an active crystal oscillator Y1; u4, K2 and other power supply networks are not shown. VCC1 represents the pull-up voltage of the internal GPIO of the CPU (U1), typically 3.3V.
Referring to fig. 2, when the power-on initialization is performed, the U1 configures its own I/O1 and I/O2 to interrupt input, and at the same time, the U1 configures corresponding registers of the U2 and the U4 through I2C, so that the serializer U2 and the deserializer U4 initialize and establish high-speed communication, and the high-speed communication is transmitted to the U4 by the U2, the GPIO1 and GPIO2 ports of the U4 are configured as input ports, the GPIO5_ REG and GPIO6_ REG ports are configured as output pins, and at the same time, the related registers are configured by initializing the touch screen controller U5, so that the touch screen can be used normally. After the touch screen controller is initialized, the I/O _2 port of the U5 is configured to be an input pin triggered by both a rising edge and a falling edge, and the level jumps once per triggering; the I/O _1 port of U5 is configured as an output pin, while the output waveform of I/O _1 changes following the input waveform change of I/O _ 2.
When the GPIO5_ REG output of U4 is high, pins A1 and C1 inside K1 are conducted, VOUT1 power supply is directly supplied to a touch screen controller, and D2, E and E2 inside K2 are conducted at the same time, so that I2C of U5 and U4 are normally communicated, after the touch screen normally works, if a human body touches the touch screen, an interrupt output pin INT of U5 generates a pulled-down interrupt signal and inputs the interrupt signal to GPIO2 of U4, the interrupt signal is transmitted to I/O2 of U1 through a serial deserializer, after the interrupt signal is received by U1, a relevant register value is read through I2C, touch coordinates are judged, and relevant application is finally executed.
When the remote touch screen normally works, the active crystal oscillator Y1 outputs fixed frequency F1, a waveform with the frequency of F2 is obtained after frequency division is carried out through U7 and is input to an I/O _2 port of U5, U5 outputs an F2 waveform with the same frequency to GPIO1 of U4 from an I/O _1 port after being processed by internal software, and at the moment, D1 flickers at the frequency of F2; and then by using the FPD-Link serializer/deserializer technology, the deserializer U4 transmits the signal of the GPIO1 to the GPIO1 of the U2 and finally inputs the signal to the I/O1 of the U1, and the U1 determines whether the waveform is F2 by detecting the level state change of the I/O1 so as to judge whether the remote touch screen is in a normal working state.
When the touch screen is disturbed by static electricity, if the touch screen controller U5 fails, the I/O _2 of U5 cannot detect the waveform with the frequency of F2 sent by U7, meanwhile, the I/O _1 of U5 cannot output the waveform of F2 to U4, after the transparent transmission of the serializer/deserializer, the I/O1 of U1 cannot detect the waveform of F2, and D1 does not flicker; at this time, the touch screen is considered to be failed, the U1 will simultaneously pull down the GPIO5_ REG and the GPIO6_ REG of the U4 through the transparent transmission action of the U2 and the U4, simultaneously pull up the GPIO5_ REG and the GPIO6_ REG after the time T1, and reconfigure the relevant registers for the I2C of the touch screen controller, so as to reinitialize the touch screen, at this time, the touch screen returns to normal, and the D1 will continue to blink.
The invention utilizes the frequency characteristic of the active crystal oscillator and the frequency division characteristic of the binary counter to generate a low-frequency signal lower than 20HZ, which is stable and reliable and is easy to detect. The use of the light-emitting diode is matched, the observation of the working state of the touch screen by naked eyes is facilitated, the abnormal reminding function is realized, the audio signal range which can be distinguished by human ears is avoided from being 20HZ-20KHZ, and the unnecessary audio noise interference is prevented; secondly, the extra burden of the CPU caused by frequent detection of the CPU is reduced, and the CPU resource is saved by adopting a fixed low-frequency signal detection method compared with a pure software application I2C bus communication polling mode, so that the software development difficulty is reduced; and the risk of electrostatic interference is reduced, and the frequency range of electrostatic noise interference is avoided. The I2C of the invention adopts the isolation control of the analog switch, thereby preventing the problem that the serial electricity between the chips can not be reset normally.
The above description is only an embodiment of the present invention, but the design concept of the present invention is not limited thereto, and any insubstantial modifications made by using the design concept should fall within the scope of infringing the present invention.
Claims (6)
1. A timing detection circuit of a vehicle-mounted split type touch screen comprises a CPU module, a touch screen controller, a serializer and a deserializer, wherein data transmission is realized between the CPU module and the touch screen controller through the serializer and the deserializer; the method is characterized in that: the system also comprises a first switching module, a second switching module, a power supply module and a signal generating module; the first switching module is connected with the power supply module and the touch screen controller to control the power supply on-off of the touch screen; the second switching module is connected between the deserializer and the touch screen controller to control the on-off of signal transmission; the signal generation module and the power supply module generate fixed frequency when power supply is switched on; the touch screen controller is connected with the signal generator so as to transmit the waveform signal with fixed frequency to the CPU module through the deserializer; the CPU module judges the working state of the touch screen according to the waveform signal and outputs a corresponding control signal to be transmitted to the deserializer; the deserializer is also connected with the first switching module to control the states of the first switching module and the second switching module according to the control signal.
2. The timing detection circuit of the vehicle-mounted split touch screen as claimed in claim 1, wherein: the touch screen controller further comprises a resistor R8 and a light emitting diode D1, wherein one end of the resistor R8 is connected with the waveform signal output end of the touch screen controller, and the other end of the resistor R8 is connected with the light emitting diode D1.
3. The timing detection circuit of the vehicle-mounted split touch screen as claimed in claim 1, wherein: the signal generation module comprises an active crystal oscillator, a magnetic bead, a resistor R3, a resistor R4, a capacitor C1, a capacitor C2 and a frequency division unit; one end of the magnetic bead is connected with the output end of the power supply module, and the other end of the magnetic bead is connected with one end of a resistor R3 and a capacitor C1; the other end of the resistor R3 is connected with an input end of an active crystal oscillator, the output end of the active crystal oscillator is connected with one end of a resistor R4, the other end of the resistor R4 is connected with the capacitor C2 and the input end of a frequency dividing unit, and the output end of the frequency dividing unit is connected with the touch screen controller.
4. The timing detection circuit of the vehicle-mounted split touch screen as claimed in claim 3, wherein: the frequency dividing unit comprises a triode Q1, a resistor R6, a resistor R7 and a binary counter, the base of the triode Q1 is connected with the other end of the resistor R4, the collector of the triode Q1 is connected with one end of a resistor R7 and the CL pin of the binary counter, the emitter of the triode Q1 is connected with one end of a resistor R6, the other end of the resistor R6 is connected with the R pin of the binary counter, and the output end of the binary counter is connected with the input end of the touch screen controller.
5. The timing detection circuit of the vehicle-mounted split touch screen as claimed in claim 1, wherein: the first switching module comprises a switch K1, a capacitor C3 and a capacitor C4; the control end of the switch K1 is connected with the output end of the power supply module, one static end of the switch K1 is connected with one end of a capacitor C4, and the other static end of the switch K1 is connected with one end of a capacitor C3 and the power supply end of the touch screen controller.
6. The timing detection circuit of the vehicle-mounted split touch screen as claimed in claim 1, wherein: the second switching module comprises a switch K2, a resistor R9, a resistor R10 and a resistor R5; the control end of the switch K2 is connected with one end of a resistor R5 and the output end of the deserializer, the first moving end and the second moving end of the switch K2 are connected with two signal ends of the deserializer, a first static end is connected with one end of a resistor R9, a second static end is connected with one end of a resistor R10, and the other end of the resistor R9 and the other end of the resistor R8 are respectively connected with two signal ends of the touch screen controller.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911233811.5A CN112925681A (en) | 2019-12-05 | 2019-12-05 | Timing detection circuit of vehicle-mounted split type touch screen |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911233811.5A CN112925681A (en) | 2019-12-05 | 2019-12-05 | Timing detection circuit of vehicle-mounted split type touch screen |
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| CN112925681A true CN112925681A (en) | 2021-06-08 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201911233811.5A Pending CN112925681A (en) | 2019-12-05 | 2019-12-05 | Timing detection circuit of vehicle-mounted split type touch screen |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117971733A (en) * | 2024-03-29 | 2024-05-03 | 智道网联科技(北京)有限公司 | Touch circuit, vehicle-mounted device mainboard and touch circuit switching method |
-
2019
- 2019-12-05 CN CN201911233811.5A patent/CN112925681A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117971733A (en) * | 2024-03-29 | 2024-05-03 | 智道网联科技(北京)有限公司 | Touch circuit, vehicle-mounted device mainboard and touch circuit switching method |
| CN117971733B (en) * | 2024-03-29 | 2024-07-12 | 智道网联科技(北京)有限公司 | Touch circuit, vehicle-mounted device mainboard and touch circuit switching method |
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