CN216353292U

CN216353292U - LED dot matrix drive circuit

Info

Publication number: CN216353292U
Application number: CN202023341891.7U
Authority: CN
Inventors: 韦天水
Original assignee: Guangzhou Chengda Intelligent Technology Co ltd
Current assignee: Guangzhou Chengda Intelligent Technology Co ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2022-04-19
Anticipated expiration: 2030-12-31

Abstract

The embodiment of the application provides an LED dot matrix driving circuit, which comprises an MCU, a first shift register, a second shift register and an LED dot matrix control circuit, wherein the LED dot matrix control circuit comprises an LED array, m row control circuits and n row control circuits, the LED array consists of m x n LED light sources, each row control circuit is connected with the anode of one row of LED light sources of the LED array, each row control circuit is connected with the cathode of one row of LED light sources of the LED array, the first shift register is connected with the plurality of row control circuits, the second shift register is connected with the plurality of row control circuits, the MCU is respectively connected with the first shift register and the second shift register, the MCU sends row control signals to the row control circuits through the first shift register, and the MCU sends row control signals to the row control circuits through the second shift register, the device models of the first shift register and the second shift register are the same. The application can reduce the number of the occupied IO ports of the MCU, and is low in cost.

Description

LED dot matrix drive circuit

Technical Field

The embodiment of the application relates to the field of LED dot matrix control, in particular to an LED dot matrix driving circuit.

Background

The existing LED lattice driving circuit adopts a driving mode of using an LED lattice, namely a special LED lattice driving IC or an integrated digital logic IC is used for building a discrete row and column driving circuit.

However, the number of input pins and the number of output pins of the existing integrated control LED driving IC are the same, which results in a large amount of occupation of the IO ports of the MCU, and different chips are used to control the row control circuit and the column control circuit of the LED dot matrix, so that the types of ICs are many and the production cost is high.

SUMMERY OF THE UTILITY MODEL

Based on this, an object of the present application is to provide an LED dot matrix driving circuit, which has the advantages of less occupation of the IO ports of the MCU, less IC types, and low cost.

In order to achieve the purpose, the utility model adopts the technical scheme that: an LED lattice driving circuit comprises an MCU, a first shift register, a second shift register and an LED lattice control circuit, wherein the LED lattice control circuit comprises an LED array, m row control circuits and n row control circuits, the LED array consists of m x n LED light sources, each row control circuit is connected with the anode of one row of LED light sources of the LED array, each row control circuit is connected with the cathode of one row of LED light sources of the LED array, the first shift register is connected with a plurality of row control circuits, the second shift register is connected with a plurality of row control circuits, the MCU is respectively connected with the first shift register and the second shift register, the MCU sends out row control signals to the row control circuits through the first shift register, and the MCU sends out row control signals to the row control circuits through the second shift register, the device models of the first shift register and the second shift register are the same.

Furthermore, the first shift register includes 1 data input terminal pin, 1 reset terminal pin, 1 clock signal control terminal pin, and a plurality of data output terminal pins, the number of the plurality of data output terminal pins of the first shift register is greater than or equal to the number of the row control circuits, and the plurality of data output terminal pins of the first shift register are respectively connected with the plurality of row control circuits in a one-to-one correspondence manner.

Furthermore, the second shift register includes 1 data input terminal pin, 1 reset terminal pin, 1 clock signal control terminal pin, and a plurality of data output terminal pins, the number of the plurality of data output terminal pins of the second shift register is greater than or equal to the number of the row control circuits, and the plurality of data output terminal pins of the second shift register are respectively connected with the plurality of row control circuits in a one-to-one correspondence manner.

Furthermore, the column control circuit comprises a first triode and a first current limiting resistor, the first shift register is connected with a base electrode of the first triode through the first current limiting resistor, an emitting electrode of the first triode is connected with a power supply voltage, and a collector electrode of the first triode is connected with an anode of the LED light source.

Further, the first triode is a PNP type triode.

Furthermore, the line control circuit comprises a second triode and a second current-limiting resistor, the second shift register is connected with the base electrode of the second triode through the second current-limiting resistor, the emitting electrode of the second triode is grounded, and the collector electrode of the second triode is connected with the cathode of the LED light source.

Further, the second triode is an NPN type triode.

Further, the first shift register and the second shift register are 8-bit serial-in, parallel-out shift registers 74HC 164.

Furthermore, the IO port of the MCU is connected to the data input terminal of the first shift register and the data input terminal of the second shift register, the IO port of the MCU is connected to the reset terminal pin and the clock signal control terminal pin of the first shift register, and the reset terminal pin and the clock signal control terminal pin of the second shift register are connected to the reset terminal pin and the clock signal control terminal pin of the first shift register in a one-to-one correspondence manner.

Furthermore, the LED dot matrix control circuit further comprises a first capacitor and a second capacitor, one end of the first capacitor and an emitting electrode of the first triode are connected to a power supply voltage, the other end of the first capacitor and an emitting electrode of the second triode are grounded, and the second capacitor is connected with the first capacitor in parallel.

Compared with the prior art, the utility model has the following beneficial effects: the MCU inputs signals to the first shift register and the second shift register, the first shift register and the second shift register are connected with the LED dot matrix control circuit, the MCU controls the first shift register and the second shift register to realize signal control of the LED dot matrix control circuit, control signals are output together after being shifted and registered, the LED dot matrix control circuit is prevented from occupying a large number of IO ports of the MCU, the first shift register and the second shift register are shift register devices of the same model, additional chips are prevented from being added, and production cost is reduced.

Drawings

Fig. 1 is a circuit diagram of an LED dot matrix driving circuit according to an embodiment of the utility model.

Detailed Description

For a better understanding and practice, the utility model is described in detail below with reference to the accompanying drawings.

Please refer to fig. 1, which is a circuit diagram of an LED dot matrix driving circuit according to an embodiment of the present application. Specifically, the embodiment of the present application includes an MCU (not shown), a first shift register 10, a second shift register 20, and an LED dot matrix control circuit 30. The MCU is respectively connected to a first shift register 10 and a second shift register 20, the first shift register 10 is connected to a column control circuit 31 of the LED dot matrix control circuit 30, and the second shift register 20 is connected to a row control circuit 32 of the LED dot matrix control circuit 30.

The LED dot matrix control circuit 30 includes an LED array, the LED array is composed of m × n LED light sources, the LED dot matrix control circuit 30 includes m column control circuits 31 and n row control circuits 32, the first shift register 10 is respectively connected to anodes of the m column LED light sources of the LED array through the m column control circuits 31, and the second shift register 20 is respectively connected to cathodes of the n row LED light sources of the LED array through the n row control circuits 32.

In one embodiment, the LED array consists of 6 by 4 LED light sources, the 24 LED light sources being LED1-LED24 in sequence. The LED dot matrix control circuit 30 includes 6

column control circuits

31 and 4 row control circuits 32, the first shift register 10 is respectively connected to anodes of 6 columns of LED light sources of the LED array through the 6 column control circuits 31, and the second shift register 20 is respectively connected to cathodes of 4 rows of LED light sources of the LED array through the 4 row control circuits 32.

In one embodiment, the first column control circuit includes a first transistor Q4 and a resistor R8, the Q0 output pin of the first shift register 74HC164 chip is connected to the base of the first transistor Q4 through the resistor R8, the emitter of the first transistor Q4 is connected to a supply voltage, the collector of the first transistor Q4 is connected to the anodes of the LED1, the LED7, the LED13 and the LED19, and the Q0 output pin of the first shift register 74HC164 chip realizes control over the LED light sources of the first column of the LED array through the first column control circuit. The resistor R8 is a current-limiting resistor, and the first triode Q4 is a PNP type triode.

The second column control circuit comprises a first triode Q5 and a resistor R9, an output pin Q1 of the first shift register 74HC164 chip is connected with a base electrode of the first triode Q5 through the resistor R9, an emitter electrode of the first triode Q5 is connected with a supply voltage, a collector electrode of the first triode Q5 is connected with anodes of the LED2, the LED8, the LED14 and the LED20, and an output pin Q1 of the first shift register 74HC164 chip realizes control over an LED light source of a second column of the LED array through the second column control circuit. The resistor R9 is a current-limiting resistor, and the first triode Q5 is a PNP type triode.

The third column control circuit comprises a first triode Q6 and a resistor R10, the output pin Q2 of the first shift register 74HC164 chip is connected with the base of the first triode Q6 through the resistor R10, the emitter of the first triode Q6 is connected with the supply voltage, the collector of the first triode Q6 is connected with the anodes of the LED3, the LED9, the LED15 and the LED21, and the output pin Q2 of the first shift register 74HC164 chip realizes the control of the LED light source of the third column of the LED array through the third column control circuit. The resistor R10 is a current-limiting resistor, and the first triode Q6 is a PNP type triode.

The fourth column control circuit comprises a first triode Q7 and a resistor R11, wherein the output pin of Q3 of the first shift register 74HC164 chip is connected with the base electrode of the first triode Q7 through the resistor R11, the emitter electrode of the first triode Q7 is connected with a supply voltage, the collector electrode of the first triode Q7 is connected with the anodes of the LED4, the LED10, the LED16 and the LED22, and the output pin of Q3 of the first shift register 74HC164 chip realizes the control of the LED light source of the fourth column of the LED array through the fourth column control circuit. The resistor R11 is a current-limiting resistor, and the first triode Q7 is a PNP type triode.

The fifth column control circuit comprises a first triode Q8 and a resistor R12, wherein the output pin of Q4 of the first shift register 74HC164 chip is connected with the base electrode of the first triode Q8 through the resistor R12, the emitter electrode of the first triode Q8 is connected with a supply voltage, the collector electrode of the first triode Q8 is connected with the anodes of the LED5, the LED11, the LED17 and the LED23, and the output pin of Q4 of the first shift register 74HC164 chip realizes the control of the LED light source of the fifth column of the LED array through the fifth column control circuit. The resistor R12 is a current-limiting resistor, and the first triode Q8 is a PNP type triode.

The sixth column control circuit comprises a first triode Q9 and a resistor R13, wherein the output pin of Q5 of the first shift register 74HC164 chip is connected with the base electrode of the first triode Q9 through the resistor R13, the emitter electrode of the first triode Q9 is connected with a supply voltage, the collector electrode of the first triode Q9 is connected with the anodes of the LED6, the LED12, the LED18 and the LED24, and the output pin of Q5 of the first shift register 74HC164 chip realizes the control of the LED light source of the sixth column of the LED array through the sixth column control circuit. The resistor R13 is a current-limiting resistor, and the first triode Q9 is a PNP type triode.

The first row control circuit comprises a second triode Q10 and a resistor R14, the output pin of Q0 of the second shift register 74HC164 chip is connected with the base electrode of the second triode Q10 through the resistor R14, the emitter electrode of the second triode Q10 is grounded, the collector electrode of the second triode Q10 is connected with the cathodes of the LEDs 1-6, and the output pin of Q0 of the second shift register 74HC164 chip realizes the control of the LED light source of the first row of the LED array through the first row control circuit. The resistor R14 is a current-limiting resistor, and the second transistor Q10 is an NPN transistor.

The second row control circuit comprises a second triode Q11 and a resistor R15, the output pin of Q1 of the second shift register 74HC164 chip is connected with the base electrode of the second triode Q11 through the resistor R15, the emitter electrode of the second triode Q11 is grounded, the collector electrode of the second triode Q11 is connected with the cathodes of the LEDs 7-12, and the output pin of Q1 of the second shift register 74HC164 chip realizes the control of the LED light sources of the second row of the LED array through the second row control circuit. The resistor R15 is a current-limiting resistor, and the second transistor Q11 is an NPN transistor.

The third row control circuit comprises a second triode Q12 and a resistor R16, the output pin of Q2 of the chip of the second shift register 74HC164 is connected with the base electrode of the second triode Q12 through the resistor R16, the emitter electrode of the second triode Q12 is grounded, the collector electrode of the second triode Q12 is connected with the cathodes of the LEDs 13-18, and the output pin of Q2 of the chip of the second shift register 74HC164 realizes the control of the third row LED light source of the LED array through the third row control circuit. The resistor R16 is a current-limiting resistor, and the second transistor Q12 is an NPN transistor.

The fourth row control circuit comprises a second triode Q13 and a resistor R17, the output pin of Q3 of the second shift register 74HC164 chip is connected with the base electrode of the second triode Q13 through the resistor R17, the emitter electrode of the second triode Q13 is grounded, the collector electrode of the second triode Q13 is connected with the cathodes of the LEDs 19-24, and the output pin of Q3 of the second shift register 74HC164 chip realizes the control of the fourth row LED light source of the LED array through the fourth row control circuit. The resistor R17 is a current-limiting resistor, and the second transistor Q13 is an NPN transistor.

In one embodiment, the first shift register 10 is an 8-bit serial input and parallel output shift register 74HC164 chip, and includes output pins Q0, Q1, Q2, Q3, Q4, Q5, Q6, and Q7, where the output pins Q0, Q1, Q2, Q3, Q4, and Q5 are respectively connected to the current limiting resistors R8, R9, R10, R11, R12, and R13 of the column control circuit 31 in a one-to-one correspondence.

The second shift register 20 is 8 serial-in parallel-out shift register 74HC164 chips, and includes output pins Q0, Q1, Q2, Q3, Q4, Q5, Q6, and Q7, where the pins Q0, Q1, Q2, and Q3 are respectively connected to the current-limiting resistors R14, R15, R16, and R17 of the row control circuit 32 in a one-to-one correspondence.

The IO port of the MCU is connected with the pins A and B, the pins CLK and the pins MR of the first shift register 74HC164 chip, and is connected with the pins A and B of the second shift register 74HC164 chip, the pin CLK of the second shift register 74HC164 chip is connected with the pin CLK of the first shift register 74HC164 chip, and the pin MR of the second shift register 74HC164 chip is connected with the pin MR of the first shift register 74HC164 chip. The pins A and B are serial data input pins, the CLK pin is a clock signal control pin, and the MR pin is a reset pin.

In the embodiment of the application, the MCU, the first shift register 10, the second shift register 20 and the LED dot matrix control circuit 30 are matched through hardware, only one IO port of the MCU is needed to input a signal, the working state of the whole LED dot matrix control circuit 30 is controlled, and the occupation of the IO port of the MCU and the quantity of control signals are greatly reduced.

The embodiment of the application further comprises filter capacitors C6 and C7, one end of each filter capacitor C6 and emitters of the first triodes Q4, Q5, Q6, Q7, Q8 and Q9 are connected to a power supply voltage, the other end of each filter capacitor C6 and emitters of the second triodes Q10, Q11, Q12 and Q13 are grounded, and the filter capacitors C7 and C6 are connected in parallel.

The working process of the present application is specifically explained below: the MCU outputs an LED dot matrix control signal to the 74HC164 chip through a 1-bit pin, the 74HC164 chip is controlled by the clock signal of the CLK pin which is output to the 74HC164 chip to shift and register the LED dot matrix control signal and convert the LED dot matrix control signal into a parallel signal which is output to the LED dot matrix control circuit, so that a plurality of column control circuits of the LED dot matrix control circuit are controlled, and the column control circuit outputs a switching signal to a column of LED light sources corresponding to the LED dot matrix according to the LED dot matrix control signal output by the 74HC164 chip to drive the LED light sources. When the LED dot matrix control circuit works, the pins Q0-Q5 of the first shift register 74HC164 chip need to output low level, and the pins Q0-Q3 of the second shift register 74HC164 chip need to output high level to enable the corresponding LED light source to emit light.

The pin Q0 of the first shift register 74HC164 chip outputs low level, and the pin Q0 of the second shift register 74HC164 chip outputs high level, i.e., the LED1 is lit; the pin Q2 of the first shift register 74HC164 chip outputs a low level, and the pin Q1 of the second shift register 74HC164 chip outputs a high level, i.e., the LED9 is lit.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, to those skilled in the art, changes and modifications may be made without departing from the spirit of the present invention, and it is intended that the present invention encompass such changes and modifications.

Claims

1. An LED dot matrix drive circuit is characterized in that: the LED array comprises m X n LED light sources, each column control circuit is connected with the anode of one column of LED light source of the LED array, each row control circuit is connected with the cathode of one row of LED light source of the LED array, the first shift register is connected with a plurality of the column control circuits, the second shift register is connected with a plurality of the row control circuits, the MCU is respectively connected with the first shift register and the second shift register, the MCU sends out column control signals to the column control circuits through the first shift register, and the MCU sends out row control signals to the row control circuits through the second shift register, the device models of the first shift register and the second shift register are the same.

2. The LED dot matrix driving circuit of claim 1, wherein: the first shift register comprises 1 data input end pin, 1 reset end pin, 1 clock signal control end pin and a plurality of data output end pins, the number of the plurality of data output end pins of the first shift register is larger than or equal to the number of the row control circuits, and the plurality of data output end pins of the first shift register are respectively connected with the plurality of row control circuits in a one-to-one correspondence mode.

3. The LED dot matrix driving circuit of claim 2, wherein: the second shift register comprises 1 data input end pin, 1 reset end pin, 1 clock signal control end pin and a plurality of data output end pins, the number of the plurality of data output end pins of the second shift register is larger than or equal to the number of the row control circuits, and the plurality of data output end pins of the second shift register are respectively connected with the plurality of row control circuits in a one-to-one correspondence mode.

4. The LED dot matrix driving circuit of claim 1, wherein: the column control circuit comprises a first triode and a first current limiting resistor, the first shift register is connected with the base electrode of the first triode through the first current limiting resistor, the emitting electrode of the first triode is connected with a power supply voltage, and the collecting electrode of the first triode is connected with the anode of the LED light source.

5. The LED dot matrix driving circuit according to claim 4, wherein: the first triode is a PNP type triode.

6. The LED dot matrix driving circuit according to claim 4, wherein: the line control circuit comprises a second triode and a second current-limiting resistor, the second shift register is connected with the base electrode of the second triode through the second current-limiting resistor, the emitting electrode of the second triode is grounded, and the collecting electrode of the second triode is connected with the cathode of the LED light source.

7. The LED dot matrix driving circuit according to claim 6, wherein: the second triode is an NPN type triode.

8. The LED dot matrix driving circuit of claim 1, wherein: the first and second shift registers are 8-bit serial-in, parallel-out shift registers 74HC 164.

9. An LED dot matrix driving circuit according to claim 3, wherein: the IO port of the MCU is respectively connected with the data input end of the first shift register and the data input end of the second shift register, the IO port of the MCU is respectively connected with the reset terminal pin and the clock signal control terminal pin of the first shift register, and the reset terminal pin and the clock signal control terminal pin of the second shift register are correspondingly connected with the reset terminal pin and the clock signal control terminal pin of the first shift register one by one.

10. An LED dot matrix driving circuit according to claim 6 or 7, wherein: the LED dot matrix control circuit further comprises a first capacitor and a second capacitor, one end of the first capacitor and an emitting electrode of the first triode are connected to a power supply voltage, the other end of the first capacitor is grounded with an emitting electrode of the second triode, and the second capacitor is connected with the first capacitor in parallel.