CN207817640U - A kind of keyboard circuit based on NE555 multi-harmonic-oscillations - Google Patents
A kind of keyboard circuit based on NE555 multi-harmonic-oscillations Download PDFInfo
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- CN207817640U CN207817640U CN201721815740.6U CN201721815740U CN207817640U CN 207817640 U CN207817640 U CN 207817640U CN 201721815740 U CN201721815740 U CN 201721815740U CN 207817640 U CN207817640 U CN 207817640U
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- circuit
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Abstract
Keyboard circuit of the utility model based on NE555 multi-harmonic-oscillations constitutes multi-resonant oscillating circuit, including NE555, button switching oscillation resistance or capacitance using NE555.Switch different resistance using button or capacitance generates unique different pulse frequency and exports, microprocessor identifies different frequencies to confirm corresponding button, arbitrary keypress function is realized only by an I/O interface of microprocessor, has greatly saved microprocessor I/O interface resources.
Description
Technical field
The utility model is related to a kind of keyboard circuit, specially a kind of keyboard circuit based on NE555 multi-harmonic-oscillations.
Background technology
In microprocessor applications, the keyboard of man-machine interface is important composition link, however the I/O interface resources of microprocessor
It is limited, take traditional Independent keys or matrix keyboard necessarily to occupy a certain number of I/O interface resources, in I/O interface quantities
In the case of scarcity, more button demands receive the restriction of I/O interface resources.
Utility model content
The purpose of this utility model is to provide a kind of keyboard circuits for saving I/O interfaces.
In order to solve the above-mentioned technical problem, the utility model uses following scheme.
A kind of keyboard circuit based on NE555 multi-harmonic-oscillations, including working power circuit, which is characterized in that when further including
Base integrated circuit and button switch oscillating circuit, and wherein button switching oscillating circuit is by multiple key switches, multiple oscillations
Capacitance or resistance composition, one of key switch and an oscillating capacitance or resistance one group of oscillating circuit branch in series,
The positive and negative extreme of working power circuit is connected on after the parallel connection of multigroup oscillating circuit branch respectively；The DIS pins of time-base integrated circuit connect
Between first resistor output end and button the switching oscillating circuit of working power circuit, the VLC pins of time-base integrated circuit,
VHC pins be connected on button switching oscillating circuit input terminal or output end, time-base integrated circuit GND pins ground connection, when basis set
Branch road in parallel with first resistor in working power circuit, time-base integrated circuit are connected at the vdd terminal and the ends REST of circuit
The ends VC by capacity earth, the OUT terminal of time-base integrated circuit carries out data output and passes through capacity earth.
The utility model has the advantage of：By with button multiple resistance or the button that constitutes of capacitance parallel connection switch oscillation
Circuit design switches the resistance of different resistance values or different capacitances using different key, to generate unique different pulse frequency
Output, microprocessor identifies different frequencies to confirm corresponding button, therefore only needs an I/O interface that multiple buttons can be realized
Function has greatly saved microprocessor I/O interface resources, increases the effective usable floor area of chip.
Description of the drawings
Fig. 1 is one circuit diagram of the utility model embodiment.
Fig. 2 is two circuit diagram of the utility model embodiment.
Specific implementation mode
The utility model is described in detail in conjunction with attached drawing.
Embodiment one
As shown in Figure 1, the keyboard circuit based on NE555 multi-harmonic-oscillations, including when working power circuit, 8 foot basis set at electricity
Road NE555 and button switch oscillating circuit, and wherein button switching oscillating circuit is by multiple key switch SB1-SBn, multiple
Oscillation resistance R1-Rn is constituted, one of key switch and an oscillation resistance one group of oscillating circuit branch in series, multigroup
The first resistor R0 output ends of working power circuit, the first electricity of working power circuit are connected on after the parallel connection of oscillating circuit branch respectively
Hold on C1；The DIS pins of 8 foot time base integrated circuit NE555 are connected on the first resistor R0 output ends and button of working power circuit
Between switching oscillating circuit, VLC pins, the VHC pins of 8 foot time base integrated circuit NE555 be connected on button switching oscillating circuit with
Between first capacitance C1 of working power circuit, the GND pins of 8 foot time base integrated circuit NE555 are grounded, and basis set is at electricity when 8 foot
The vdd terminal of road NE555 and the ends REST are connected on branch road in parallel with first resistor R0 in working power circuit, basis set when 8 foot
At the ends VC of circuit by the second capacitance C0 ground connection, the OUT terminal of 8 foot time base integrated circuit NE555 carries out data output and passes through
Third capacitance C ground connection.
Embodiment two
As shown in Fig. 2, the keyboard circuit based on NE555 multi-harmonic-oscillations, including when working power circuit, 8 foot basis set at electricity
Road NE555 and button switch oscillating circuit, and wherein button switching oscillating circuit is by multiple key switch SB1-SBn, multiple
Oscillating capacitance C1-Cn is constituted, one of key switch and an oscillation resistance one group of oscillating circuit branch in series, multigroup
The second resistance R1 output ends of working power circuit, the cathode of working power circuit are connected on after the parallel connection of oscillating circuit branch respectively
End；The DIS pins of 8 foot time base integrated circuit NE556 are connected on the first resistor R0 output ends and working power of working power circuit
Between the second resistance R1 input terminals of circuit, VLC pins, the VHC pins of 8 foot time base integrated circuit NE555 are connected on button switching
Between oscillating circuit and the second resistance R1 output ends of working power circuit, the GND pins of 8 foot time base integrated circuit NE555 connect
Switch the output end of oscillating circuit in button, the vdd terminal of 8 foot time base integrated circuit NE555 and the ends REST are connected on working power
Branch road in parallel with first resistor R0 in circuit, the ends VC of 8 foot time base integrated circuit are by the second capacitance C0 ground connection, when 8 foot
The OUT terminal of base integrated circuit NE555 carries out data output and is grounded by third capacitance C.
NE556 also can be selected in time-base integrated circuit.
Keyboard circuit of the utility model based on NE555 multi-harmonic-oscillations constitutes multi-resonant oscillating circuit using NE555, including
NE555, button switching oscillation resistance or capacitance.Switch different resistance using button or capacitance generates unique different pulse frequency
Rate exports, and microprocessor identifies different frequencies to confirm corresponding button, only by an I/O interface reality of microprocessor
Incumbent meaning keypress function, has greatly saved microprocessor I/O interface resources.
Claims (1)
1. a kind of keyboard circuit based on NE555 multi-harmonic-oscillations, including working power circuit, which is characterized in that base when further including
Integrated circuit and button switch oscillating circuit, and wherein button switching oscillating circuit is by multiple key switches, multiple oscillations electricity
Perhaps resistance composition, one of key switch and an oscillating capacitance or resistance one group of oscillating circuit branch in series, it is more
The positive and negative extreme of working power circuit is connected on after the parallel connection of group oscillating circuit branch respectively；The DIS pins of time-base integrated circuit are connected on
Between first resistor output end and button the switching oscillating circuit of working power circuit, VLC pins, the VHC of time-base integrated circuit
Pin be connected on button switching oscillating circuit input terminal or output end, time-base integrated circuit GND pins ground connection, when basis set at electricity
The vdd terminal on road and the ends REST are connected on branch road in parallel with first resistor in working power circuit, the VC of time-base integrated circuit
End carries out data output and passes through capacity earth by capacity earth, the OUT terminal of time-base integrated circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721815740.6U CN207817640U (en) | 2017-12-22 | 2017-12-22 | A kind of keyboard circuit based on NE555 multi-harmonic-oscillations |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721815740.6U CN207817640U (en) | 2017-12-22 | 2017-12-22 | A kind of keyboard circuit based on NE555 multi-harmonic-oscillations |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207817640U true CN207817640U (en) | 2018-09-04 |
Family
ID=63329939
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201721815740.6U Expired - Fee Related CN207817640U (en) | 2017-12-22 | 2017-12-22 | A kind of keyboard circuit based on NE555 multi-harmonic-oscillations |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207817640U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109394262A (en) * | 2018-09-19 | 2019-03-01 | 深圳市威尔德医疗电子有限公司 | A kind of color ultrasound keypad and ultrasonic system |
-
2017
- 2017-12-22 CN CN201721815740.6U patent/CN207817640U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109394262A (en) * | 2018-09-19 | 2019-03-01 | 深圳市威尔德医疗电子有限公司 | A kind of color ultrasound keypad and ultrasonic system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20180904 Termination date: 20191222 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |