CN214591372U - Capacitor key detection chip and capacitor key keyboard - Google Patents

Abstract

The invention provides a capacitor key detection chip, which can convert the capacitance value of a capacitor key into a corresponding digital value, has the function of cascade expansion in a scanning chain manner, can be conveniently used in a serial expansion manner, integrates the driving of a light emitting diode, and can be applied to the field of capacitor key keyboards due to the characteristics, so that the capacitor key keyboards with high efficiency, reliability and low cost are developed.

Description

Capacitor key detection chip and capacitor key keyboard

Technical Field

The invention relates to a chip, in particular to a capacitor key detection chip.

Background

The current keyboard implementation modes can be mainly divided into mechanical keyboards, optical signal keyboards, magnetic signal keyboards and membrane keyboards. The mechanical keyboard judges the state of the keys by sensing the connection and disconnection of the metal contacts; the optical signal keyboard judges the key state by detecting whether the light path is blocked; the magnetic signal keyboard judges the key state by detecting whether the strength of the magnetic signal reaches a trigger threshold value; the membrane keyboard judges the state of the keys by detecting the connection on-off of the metal contact and the conductive material. The key detection principle of the various types of keyboards is influenced by dust, and particularly, the dust directly influences the contact conduction characteristics of the mechanical keyboard and the thin-film keyboard; dust can affect the light intensity of the optical signal keyboard, and the magnetic signal keyboard can also be affected by the dust with magnetic conductivity.

The capacitor key keyboard represents the state of keys according to the size of key capacitors and cannot be influenced by dust, the existing capacitor key keyboards are based on matrix layout and control modes, the layout and control modes need partition scanning, the detection speed is low, an LED control matrix is added besides the key control matrix and used for achieving the light effect of the keyboard, and the layout of the keyboard is very complex.

Disclosure of Invention

The invention aims to provide a capacitor key detection chip, and aims to solve the problems of complex layout and high cost of capacitor key keyboard keys and RGB lamp circuits.

The first aspect of the embodiments of the present invention provides a capacitor detection chip, where the capacitor key detection chip includes a capacitor detection module, a communication module and a light emitting diode driving module, and the capacitor key detection chip may be cascaded and expanded for use in a series connection manner;

the capacitance detection module is used for detecting the capacitance value of the capacitance key and converting a corresponding digital value according to the size of the capacitance value of the key;

the serial communication module is used for communicating with a previous-stage capacitor key detection chip or a main controller and communicating with a next-stage capacitor key detection chip or the main controller, sending control information of the main controller to the capacitor key detection chip, and sending a digital value converted by the capacitor detection module or state information of the chip to the main controller;

the light emitting diode driving module is used for driving an off-chip light emitting diode;

in one embodiment, the capacitive key detection chip pins include a clock input pin, a clock output pin, a data input pin and a data output pin, the clock input pin is used for receiving a clock signal from the main control chip or a previous capacitive key detection chip, the clock output pin is used for transmitting the clock signal received from the main control chip to a next capacitive key detection chip, the data input pin is used for receiving a data signal received from the main control chip or the previous capacitive key detection chip, and the data output pin is used for transmitting the data signal to a next capacitive key detection chip or a main controller.

In one embodiment, the power supply end of the capacitive key detection chip is used for providing power supply voltage for the chip, and the ground end of the capacitive key detection chip is used for providing ground voltage for the chip.

In one embodiment, the led driving module of the capacitive key detection chip may drive one or more leds, or may not drive leds.

In one embodiment, the capacitive key detection chip sends the digital value converted by the capacitive detection module to the main controller through the communication interface, and the main controller compares the digital value with a set trigger threshold to determine whether the key is pressed, where the trigger thresholds of different keys may be different, and the trigger threshold of each key may also be set arbitrarily.

A second aspect of the embodiments of the present invention provides a capacitive keypad keyboard, which includes a main controller, one or more capacitive keys, and one or more capacitive key detection chips as described above.

Drawings

The above and other features, nature, and advantages of the present invention will become more apparent from the following description of the embodiments when taken in conjunction with the accompanying drawings in which like reference characters identify correspondingly throughout and wherein:

FIG. 1 is a system diagram of a capacitive key detection chip according to the present invention;

FIG. 2 is a schematic diagram of a pin of the capacitive button detection chip according to the present invention;

FIG. 3 illustrates a schematic diagram of a capacitive keypad of the present invention;

reference numerals:

100, 100_1, 100_2, 100_ 3-capacitive key detection chip;

101, 101_1, 101_2, 101_3 — capacitive key detection chip power pin;

102, 102_1, 102_2, 102_3 — capacitive key detection chip ground pin;

103, 103_1, 103_2, 103_3 — capacitive key detection chip clock input pin;

104, 104_1, 104_2, 104_3 — capacitive key detection chip clock output pin;

105, 105_1, 105_2, 105_3 — capacitive key detection chip data input pin;

106, 106_1, 106_2, 106_3 — capacitive key detection chip data output pin;

107, 107_1, 107_2, 107_3 — capacitive key detection chip led driver pin 1;

108, 108_1, 108_2, 108_3 — capacitive key detection chip led driver pin 2;

109, 109_1, 109_2, 109_3 — capacitive key detection chip led driver pin 3;

110, 110_1, 110_2, 110_3 — capacitive key detection chip detects capacitive pins;

120-capacitive key detection chip communication module;

121-capacitive key detection chip capacitive detection module;

122-capacitive key detect chip LED drive module;

130_1, 130_2, 130_3 — capacitive keys;

140 — master controller;

141 — master controller clock output pin;

142 — host controller data output pin;

143 — master controller data input pins;

150 — system ground;

151 — system power supply.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Embodiments of the present invention will now be described with reference to the accompanying drawings in detail. Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Further, although the terms used in the present invention are selected from publicly known and used terms, some of the terms mentioned in the description of the present invention may be selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Furthermore, it is required that the present invention is understood, not simply by the actual terms used but by the meaning of each term lying within.

Fig. 1 is a diagram of main functional blocks of a capacitive key sensing chip, the capacitive key sensing chip 100 includes a communication module 120, a capacitive sensing module 121, and a light emitting diode driving module 122, a VDD pin 101 is a power port of the chip, a VSS pin 102 is a ground port of the chip, an SCK _ I pin 103 is a clock input port of the chip, an SCK _ O pin 104 is a clock output port of the chip, an SDI pin 105 is a data input port of the chip, an SDO pin 106 is a data output port of the chip, a LED1 pin 107, an LED2 pin 108, and an LED3 pin 109 are three light emitting diode driving pins of the chip, and a CIO pin 110 is a sensing capacitive pin of the chip. The SCK _ I pin 103 and the SDI pin 106 are connected with the communication module 120 to provide a communication clock and input communication data for the chip; the SCK _ O pin 104 and the SDO pin 106 are connected to the communication module 120, and send a communication clock and output data to the outside of the chip; the communication module 120 is connected to the capacitance detection module 121, and provides control information for the capacitance detection module 121 and reads out output information of the capacitance detection module 121; the communication module 120 is connected to the led driving module 122, and provides control information for the led driving module 122; the CIO pin 110 is connected with the capacitance detection module; the LED1 pin 107, the LED2 pin 108 and the LED3 pin 109 are connected to the LED driving module 122, and control the LED light effect outside the chip.

The first embodiment is as follows:

fig. 2 shows a pin diagram of the capacitive key detection chip according to the present invention.

As shown in fig. 2, the capacitive button detection chip has the following pins: a power supply pin VDD-101, a ground pin VSS-102, a clock input pin SCK _ I-103, a clock output pin SCK _ O-104, a data input pin SDI-105, a data output pin SDO-106, a light emitting diode 1 drive pin LED 1-107, a light emitting diode 2 drive pin LED 2-108, a light emitting diode 3 drive pin LED 3-109, and a detection capacitor pin CIO-110.

In the embodiment, the capacitive button is connected to the CIO pin 110, and the button capacitance detection chip 100 converts a corresponding digital value according to a capacitance value of the capacitive button. The clock input pin SCK _ I103, the data input pin SDI 105 and the output pin SDO 106 can control or inquire the working state of the key capacitance detection chip 100, read the conversion result, and control the working state of the LED1 pin 107, the LED2 pin 108 and the LED3 pin 109, thereby controlling the working state of the LED lamp driven by the chip. The clock output pin SCK _ O104 buffers and outputs the clock signal of the clock input pin SCK _ I103.

In another embodiment, there may be only one or n led driving pins, or no led driving pins.

In another embodiment, the SCK _ O pin 106 may be eliminated.

Example two:

fig. 3 is a schematic diagram of a capacitive keypad according to the present invention, in which three capacitive keys, three capacitive key detection chips and a main controller are taken as examples to illustrate the working principle of the capacitive keypad.

As shown in fig. 3, the capacitive keypad 200 includes a main controller 140, three capacitive keys 130_1, 130_2, and 130_3, and three capacitive key detecting chips 100_1, 100_2, and 100_ 3; the power pins 101_1, 101_2, 101_3 of the three capacitive key detection chips 100_1, 100_2, 100_3 are connected to the system power supply VDD 151; the ground pins 102_1, 102_2 and 102_3 of the three capacitive key detection chips 100_1, 100_2 and 100_3 are connected to a system ground VSS 150; the three capacitive buttons 130_1, 130_2 and 130_2 are respectively connected to the CIO pins 110_1 and 110_2 and 110_3 of the CIO pins 110_1 and 100_2 and 100_3 of the capacitive button detection chip 100_ 1; the clock SCK _ O of the main controller 140 is connected to the clock input pin SCK _ I103 _1 of the capacitive key detecting chip 100_1, the clock output pin SCK _ O104 _1 of the capacitive key detecting chip 100_1 is connected to the clock input pin SCK _ I103 _2 of the capacitive key detecting chip 100_2,

the clock output pin SCK _ O104 _2 of the capacitive key detection chip 100_2 is connected to the clock input pin SCK _ I103 _3 of the capacitive key detection chip 100_ 3; the data output pin SDO 142 of the main controller 140 is connected to the data input pin SDI 105_1 of the capacitive key detection chip 100_1, the data output pin SDO 106_1 of the capacitive key detection chip 100_1 is connected to the data input pin SDI 105_2 of the capacitive key detection chip 100_2, the data output pin SDO 106_2 of the capacitive key detection chip 100_2 is connected to the data input pin SDI 105_3 of the capacitive key detection chip 100_3, and the data output pin SDO 106_3 of the capacitive key detection chip 100_3 is connected to the data input pin SDI 143 of the main controller 140; the led driving pins 107_1, 108_1, 109_1, 107_2, 108_2, 109_2, 107_3, 108_3, and 109_3 of the three capacitive key detecting chips 100_1, 100_2, and 100_2 are respectively connected to the cathode of one led, and the anode of the led is connected to the system power supply VDD 151.

In the second embodiment, the clock input pins SCK _ I103 _2 and 103_3 of the capacitive key detecting chips 100_2 and 100_3 are respectively connected to the clock output pin of the previous capacitive key detecting chip, and in another embodiment, the clock input pins SCK _ I of all the capacitive key detecting chips may be directly connected to the clock output pin of the host controller instead of the clock output pin of the previous capacitive key detecting chip.

In the second embodiment, three capacitive key detecting chips 100_1, 100_2 and 100_3 constitute one scan chain, and in another embodiment, a plurality of capacitive key detecting chips may constitute a plurality of scan chains.

In the second embodiment, each capacitive key detection chip drives three light emitting diodes, and in another embodiment, each capacitive key detection chip may drive only one light emitting diode or may not drive the light emitting diodes.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that these are by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.

Claims (8)

1. A capacitor key detection chip is characterized in that: the capacitance key detection chip comprises a capacitance detection module, a communication module and a light emitting diode driving module, and can be used in a scanning chain manner in a cascading and expanding manner;

the capacitance detection module is used for detecting the capacitance value of the capacitance key and converting a corresponding digital value according to the size of the capacitance value of the key;

the serial communication module is used for communicating with a previous-stage capacitor key detection chip or a main controller and communicating with a next-stage capacitor key detection chip or the main controller, sending control information of the main controller to the capacitor key detection chip, and sending a digital value converted by the capacitor detection module or state information of the chip to the main controller;

and the light emitting diode driving module is used for driving the off-chip light emitting diode.

2. The capacitive button detection chip of claim 1, wherein: the capacitor key detection chip pins comprise a clock input pin, a clock output pin, a data input pin and a data output pin, wherein the clock input pin is used for receiving clock signals from the main control chip or a previous capacitor key detection chip, the clock output pin is used for transmitting the clock signals received from the main control chip to a next capacitor key detection chip, the data input pin is used for receiving data signals received from the main control chip or the previous capacitor key detection chip, and the data output pin is used for sending the data signals to a next capacitor key detection chip or a main controller.

3. The capacitive button detection chip of claim 1, wherein: the power supply end of the capacitor key detection chip is used for providing power supply voltage for the chip, and the ground end of the capacitor key detection chip is used for providing ground voltage for the chip.

4. The capacitive button detection chip of claim 1, wherein: the light emitting diode driving module of the capacitance key detection chip can drive one or more light emitting diodes or not drive the light emitting diodes.

5. The capacitive button detection chip of claim 1, wherein: the capacitance key detection chip sends the digital value converted by the capacitance detection module to the main controller through the communication interface, the main controller compares the digital value with a set trigger threshold value to judge whether the key is pressed, the trigger threshold values of different keys can be different, and the trigger threshold value of each key can be set at will.

6. A capacitive keypad, comprising: the capacitive touch key detection chip comprises a main controller, one or more capacitive touch keys and one or more capacitive touch key detection chips as claimed in any one of claims 1 to 5.

7. The capacitive keypad of claim 6, wherein: the capacitive key detection chip can be distributed on one scan chain or a plurality of scan chains.

8. The capacitive keypad of claim 6, wherein: each capacitive key detection chip may or may not drive one or more light emitting diodes.

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