Multipath LED control circuit for multiplexing AD interface and IO interface

Abstract

The utility model relates to the technical field of LED (light-emitting diode) control circuits, in particular to a multi-path LED control circuit for multiplexing an AD (analog-to-digital) interface and an IO (input-output) interface. The device comprises a single-chip microcomputer, an LED display module and an AD sampling circuit. The single-chip microcomputer is in adaptive connection with the LED display module and is used for sending a control signal to the LED display module and controlling a light-emitting diode in the LED display module to be powered on or powered off. The AD sampling circuit is in adaptive connection with the single-chip microcomputer and is used for sending sampling signals to the single-chip microcomputer. The system is characterized in that the AD sampling circuit and the LED display module multiplex IO ports of the single-chip microcomputer. By adopting the control circuit, more functions can be realized without adding a singlechip interface.

Description

Technical Field

[0001] The utility model relates to the technical field of LED control circuits, specifically a multi-channel LED control circuit with multiplexed AD interface and IO interface. Background Art

[0002] In order to reduce the hardware cost and better meet the consumer market, many manufacturers have launched single-chip microcomputers with smaller packages and fewer pins, which can be used to design relatively simple circuits and products with high cost performance. However, due to the limitation of fewer interfaces, more complex scheme designs cannot be supported. Therefore, how to implement more functions with limited interfaces has become a problem that needs to be optimized. Summary of the Utility Model

[0003] The technical problem to be solved by the utility model is to provide a multi-channel LED control circuit with multiplexed AD interface and IO interface. By using this control circuit, more functions can be realized without increasing the interfaces of the single-chip microcomputer.

[0004] To solve the above problems, the following technical solutions are provided:

[0005] The multi-channel LED control circuit with multiplexed AD interface and IO interface of the utility model includes a single-chip microcomputer, an LED display module, and an AD sampling circuit. The single-chip microcomputer is adaptively connected to the LED display module and is used to send control signals to the LED display module to control the lighting or power-off of the light-emitting diodes in the LED display module. The AD sampling circuit is adaptively connected to the single-chip microcomputer and is used to send sampling signals to the single-chip microcomputer. Its feature is that the AD sampling circuit and the LED display module multiplex the IO ports of the single-chip microcomputer.

[0006] Among them, the interfaces of the LED display module connected to the single-chip microcomputer are the K-UP interface, the FICED interface, and the Tmos interface. The K-UP interface, the FICED interface, and the Tmos interface are respectively connected to three IO ports of the single-chip microcomputer. The Tmos interface of the LED display module multiplexes the IO port of the single-chip microcomputer with the AD sampling circuit.

[0007] In the LED display module, the working voltage of those light-emitting diodes with anodes connected to the Tmos interface is above 2.5V.

[0008] The AD sampling circuit is a temperature sampling circuit.

[0009] The AD sampling circuit includes a thermistor NTC. The lower end of the thermistor NTC is grounded, and the upper end of the thermistor NTC is connected to one end of a resistor R20, one end of a resistor R14, and one end of a capacitor C19 respectively. The other end of the resistor R20 is connected to the power supply VDD, and the other end of the capacitor C19 is grounded. The other end of the resistor R14 is connected to one end of a capacitor C9, and the other end of the capacitor C9 is grounded. One end of the resistor R14 connected to the capacitor C9 is connected to the single-chip microcomputer to output a sampling signal to the single-chip microcomputer. One end of the resistor R14 connected to the capacitor C9 and the LED display module share the I / O port of the single-chip microcomputer.

[0010] The single-chip microcomputer uses a chip U2 with the model FU6572T.

[0011] Adopting the above scheme has the following advantages:

[0012] Since the AD interface and I / O interface of the multi-channel LED control circuit of the present invention are multiplexed, the AD sampling circuit and the LED display module of the multi-channel LED control circuit share the I / O port of the single-chip microcomputer. By adopting the multiplexing scheme, without adding multiplexing interfaces, the control of LED display is realized, and AD sampling is also realized. Furthermore, the effect of completing more functions with limited interfaces is achieved. Description of the Drawings

[0013] Figure 1 is a circuit schematic diagram of the multi-channel LED control circuit with multiplexed AD interface and I / O interface of the present invention;

[0014] Figure 2 is a circuit schematic diagram of the AD sampling circuit and the LED display module in the multi-channel LED control circuit with multiplexed AD interface and I / O interface of the present invention;

[0015] Figure 3 is a circuit schematic diagram of the single-chip microcomputer in the multi-channel LED control circuit with multiplexed AD interface and I / O interface of the present invention;

[0016] Figure 4 is the first software screenshot of the multi-channel LED control circuit with multiplexed AD interface and I / O interface of the present invention in the running state;

[0017] Figure 5 is the second software screenshot of the multi-channel LED control circuit with multiplexed AD interface and I / O interface of the present invention in the running state;

[0018] Figure 6 is the third software screenshot of the multi-channel LED control circuit with multiplexed AD interface and I / O interface of the present invention in the running state;

[0019] Figure 7This is the fourth software screenshot of the multiplexed LED control circuit with AD interface and IO interface multiplexing of the present utility model in the operating state. Specific embodiments

[0020] The present utility model will be further described in detail below with reference to the accompanying drawings.

[0021] As Figure 1 shown, the multiplexed LED control circuit with AD interface and IO interface multiplexing of the present utility model includes a single-chip microcomputer, an LED display module, and an AD sampling circuit. The single-chip microcomputer is adaptively connected to the LED display module for sending control signals to the LED display module to control the energization or de-energization of the light-emitting diodes in the LED display module. The AD sampling circuit is adaptively connected to the single-chip microcomputer for sending sampling signals. As Figure 3 shown, in this embodiment, the single-chip microcomputer uses the chip U2 of the model FU6572T. The FU6572T series of chips have fewer interfaces and lower costs. The chip U2 has a peripheral circuit for driving its operation. The specific structure is as Figure 3 shown, which belongs to the prior art and will not be elaborated here.

[0022] As Figure 1 and Figure 2 shown, the interfaces of the LED display module connected to the single-chip microcomputer are the K-UP interface, the FICED interface, and the Tmos interface. The K-UP interface, the FICED interface, and the Tmos interface are respectively connected to three IO ports of the single-chip microcomputer. The Tmos interface of the LED display module multiplexes the IO port of the single-chip microcomputer with the AD sampling circuit. In this embodiment, the K-UP interface is connected to the 18th pin (GP35 pin) of the chip U2, the FICED interface is connected to the 8th pin (GP12 pin) of the chip U2, and the Tmos interface is connected to the 13th pin (GP26 pin) of the chip U2.

[0023] In this embodiment, the LED display module contains 6 light-emitting diodes, three power display lights, and three gear display lights. This design does not require an external pull-up or ground, and accurate control of each LED can be achieved by configuring the input and output of the three-way IO. The circuit structure of the LED display module is as Figure 2 shown, which belongs to the prior art and will not be elaborated here.

[0024] The AD sampling circuit is a temperature sampling circuit. The AD sampling circuit includes a thermistor NTC. The lower end of the thermistor NTC is grounded. The upper end of the thermistor NTC is respectively connected to one end of a resistor R20, one end of a resistor R14, and one end of a capacitor C19. The other end of the resistor R20 is connected to the power supply VDD, and the other end of the capacitor C19 is grounded. The other end of the resistor R14 is connected to one end of a capacitor C9, and the other end of the capacitor C9 is grounded. One end of the resistor R14 connected to the capacitor C9 is connected to the single-chip microcomputer, and a sampling signal is output to the single-chip microcomputer. One end of the resistor R14 connected to the capacitor C9 and the LED display module share the IO port of the single-chip microcomputer. In this embodiment, one end of the resistor R14 connected to the capacitor C9 and the Tmos interface of the LED display module share the 13th pin of the chip U2.

[0025] The control principle of this solution is that when the single-chip microcomputer pin is used for AD sampling, the corresponding AD channel is opened and configured as an input. When used as a general IO, the channel enable of the AD is turned off and configured as an output. In the program, the input and output states are configured by continuously scanning. In order to reduce the influence of the voltage during AD sampling on the light-emitting diode, the AD sampling time and period can be minimized as much as possible, so that it is in the output state for most of the time. For the light-emitting diode whose anode is connected to the sampling circuit through the shared IO port, it must be selected with a working voltage above 2.5V. For example, the model of the light-emitting diode used in the solution is LTST-C191TGKT, and the forward conduction voltage is about 3V.

[0026] The following elaborates on the specific working logic of this design. D7, D9, and D10 are used as gear display lights, D6, D8, and D13 are used for power display, and Tmos is used as a general IO and the AD channel enable is turned on at fixed intervals to sample voltage signals. When D8 and D6 need to be lit separately, first set a loop function to scan the IO port status every 2ms. When idle, set its input to 0. The program is as Figure 4 shown. When GP35 is set to low level and GP12 is set to high level, D8 can be lit. The program is as Figure 5 shown. When GP35 is low level and GP12 is high, D6 can be lit. The program is as Figure 6 shown. While the LED is lit, the AD enable is turned on to sample the voltage about every 0.5S, and the AD sampling is turned off at other times. The program is as Figure 7 shown.

[0027] The multiplexed LED control circuit with multiplexed AD interface and IO interface of the present utility model adopts a multiplexing solution. Without adding multiplexed interfaces, it not only realizes the control of LED display, but also realizes AD sampling, and further realizes the effect of completing more functions with limited interfaces.

Claims

1. A multi-channel LED control circuit with multiplexing of AD interface and IO interface, comprising a single-chip microcomputer, an LED display module and an AD sampling circuit; the single-chip microcomputer is adaptively connected to the LED display module, used to send a control signal to the LED display module to control the power on or off of the light-emitting diodes in the LED display module; the AD sampling circuit is adaptively connected to the single-chip microcomputer, used to send a sampling signal to the single-chip microcomputer; characterized in that: The AD sampling circuit and the LED display module reuse the IO port of the single chip microcomputer.

2. The multi-channel LED control circuit with multiplexing of AD interface and IO interface as claimed in claim 1, characterized in that: The interfaces connecting the LED display module to the single-chip microcomputer are K-UP interface, FICED interface and Tmos interface, and the K-UP interface, FICED interface and Tmos interface are respectively connected to three IO ports of the single-chip microcomputer; the Tmos interface of the LED display module and the AD sampling circuit multiplex the IO port of the single-chip microcomputer.

3. The multi-channel LED control circuit with multiplexing of AD interface and IO interface as claimed in claim 2, characterized in that: In the LED display module, the operating voltage of the light emitting diodes whose anodes are connected to the Tmos interface is above 2.5V.

4. The multi-channel LED control circuit with multiplexing of AD interface and IO interface as claimed in claim 1, characterized in that: The AD sampling circuit is a temperature sampling circuit.

5. The multi-channel LED control circuit with multiplexing of AD interface and IO interface as claimed in claim 4, characterized in that: The AD sampling circuit contains a thermistor NTC, the lower end of the thermistor NTC is grounded, the upper end of the thermistor NTC is respectively connected to one end of a resistor R20, one end of a resistor R14 and one end of a capacitor C19, the other end of the resistor R20 is connected to a power supply VDD, and the other end of the capacitor C19 is grounded; the other end of the resistor R14 is connected to one end of a capacitor C9, the other end of the capacitor C9 is grounded, one end of the resistor R14 connected to the capacitor C9 is connected to a single-chip microcomputer, and a sampling signal is output to the single-chip microcomputer; one end of the resistor R14 connected to the capacitor C9 and the LED display module reuse the IO port of the single-chip microcomputer.

6. The multi-channel LED control circuit with multiplexing of AD interface and IO interface as claimed in claim 1, characterized in that: The single chip microcomputer adopts chip U2 with model number FU6572T.

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