CN1667551A - Electronic device using multiple push keys - Google Patents
Electronic device using multiple push keys Download PDFInfo
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- CN1667551A CN1667551A CN 200410008030 CN200410008030A CN1667551A CN 1667551 A CN1667551 A CN 1667551A CN 200410008030 CN200410008030 CN 200410008030 CN 200410008030 A CN200410008030 A CN 200410008030A CN 1667551 A CN1667551 A CN 1667551A
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- resistance
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- electronic installation
- resistance string
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Abstract
The invention relates to an electronic apparatus able to use a plurality of keys, which comprises the first electric resistance string with the first head and the second head, the second electric resistance with the third head and the forth head, a plurality of keys and an output joint.The first head of the first electric resistance string is connected to high voltage electricity and the second head of the first electric resistance string is connected to the third head of the second electric resistance string, while the forth head of the second electric resistance string is connected to low voltage electricity, besides, the first and the second electric resistance string separately have p and q series resistances, and p plus q is M.Each key is connected to at least one electric resistance and output joint is located between the first and the second electric resistances, wherein, output joint is used to output analog signal.
Description
Technical field
The present invention is relevant for a kind of electronic installation, and particularly relevant for a kind of electronic device using multiple push keys.
Background technology
In traditional electronic installation, a kind of common key circuit design directly is connected to button general input and output (the General Purpose Input Output of microprocessor (micro processor), GPIO) pin (pin), and directly judge the state of button by microprocessor itself.
Yet,,,, will take many GPIO pins so connect the bond number amount more for a long time when what need because of all special-purpose GPIO pin of each button though the design of this kind key circuit has simply, direct advantage.Because the GPIO pin of microprocessor is limited, so the GPIO pin of preciousness can't be wasted on the key circuit greatly.Therefore, the design of this kind key circuit is more inapplicable on the more electronic installation of number of keys.
A kind of analog-digital converter (Analog-to-Digital Converter, ADC) keyboard (keypad) in order to save the use of GPIO pin, to develop then.Please refer to Fig. 1, its expression tradition has the part circuit diagram of the electronic installation of ADC keyboard.ADC keyboard 20 in the electronic installation 10 comprises a resistance string 16, a M button SW
1-SW
M, and an output node (node) 30.
Resistance string 16 has the resistance R of M+1 series connection
0-R
M, and two ends of resistance string are electrically connected with a high voltage Vcc and a ground voltage respectively.Two ends of each button respectively with ground voltage and two adjacent resistance between node be electrically connected.And 30 of output nodes are in resistance R
0With R
1Between, in order to export an aanalogvoltage.This aanalogvoltage is corresponding to the state of M button.The aanalogvoltage that output node 30 is exported is converted to the digital signal of a correspondence earlier via ADC 50, afterwards, by the microprocessor 60 of electronic installation this digital signal is handled, to carry out the function corresponding to key-press status again.
By above as can be known, ADC keyboard 20 can use the ADC I/O port to reach the purpose of saving the GPIO pin.Can reduce the use number of the GPIO pin of microprocessor though it should be noted that the ADC keyboard, the button of ADC keyboard 20 does not have the function of compound keys.For instance, when button SW1 and SW2 were pressed simultaneously, microprocessor 60 will be judged as only had button SW1 to be pressed.So, when the button of electronic installation has two above compound keys of the use of needs, just must increase the ADC I/O port.Therefore, need not increase under the prerequisite of ADC I/O port, how allow the button of electronic installation have the function of compound keys, must make great efforts improved direction for all relevant practitioners in fact.
Summary of the invention
In view of this, purpose of the present invention is providing a kind of electronic device using multiple push keys exactly, except the number of the GPIO pin that can reduce needed microprocessor significantly, just can allow the button of electronic installation have the function of compound keys with single ADC I/O port.
According to purpose of the present invention, a kind of electronic device using multiple push keys is proposed, comprise one first resistance string, one second resistance string, a N button and an output node.First resistance string has one first end and one second end, and second resistance string has one the 3rd end and one the 4th end.First end of first resistance string is electrically connected with a high voltage.Second end of first resistance string is connected with the 3rd end of second resistance string.The 4th end of second resistance string is electrically connected with a low-voltage.In addition, first resistance string has the resistance of p series connection, and second resistance string then has the resistance of q series connection.The summation of p and q is M, and M is the positive integer more than or equal to 3.Each button is in parallel with at least one resistance.Output node is arranged between first resistance string and second resistance string.Output node is in order to export a simulating signal.The voltage of simulating signal is corresponding to the state of M button.
Description of drawings
Fig. 1 represents that tradition has the part circuit diagram of the electronic installation of ADC keyboard;
Fig. 2 represents the part circuit diagram according to the electronic device using multiple push keys of one first embodiment of the present invention; And
Fig. 3 represents the part circuit diagram according to the electronic device using multiple push keys of one second embodiment of the present invention.
The drawing reference numeral explanation
10,100,200: electronic installation
16: resistance string
The 20:ADC keyboard
30,140,240: output node
50,150,250: analog-digital converter
60,160,260: microprocessor
120,220: the first resistance string
130,230: the second resistance string
Embodiment
Embodiment one
Please refer to Fig. 2, its expression is according to the part circuit diagram of the electronic device using multiple push keys of the present invention one first embodiment.The electronic installation 100 of present embodiment comprises one first resistance string 120,130,6 button SW1-SW6 of one second resistance string, an output node (node) 140, an analog-digital converter (Analog-to-Digital Converter; ADC) 150 and one microprocessor (microprocessor) 160.
In this embodiment, first resistance string 120 has the resistance of 3 series connection, and the resistance value of these 3 resistance from top to bottom is R1, R2 and R3 in regular turn.Second resistance string 130 has the resistance of 3 series connection too, and its resistance value from top to bottom is R1 ', R2 ' and R3 ' in regular turn.One end of first resistance string 120 is electrically connected with a high voltage Vcc, and the other end then is connected with an end of second resistance string 130.The other end of second resistance string 130 is electrically connected with a ground voltage.
In addition, button SW1-SW6 is in parallel with resistance R 1-R3 and R1 '-R3 ' respectively.Has output node 140 between first resistance string 120 and second resistance string 130, in order to export a simulating signal SA.The voltage of simulating signal SA is corresponding to the state of button.Simulating signal SA converts microprocessor 160 accessible digital signals to by the ADC 150 that is electrically connected with output node 140 earlier, afterwards, is handled by the microprocessor 160 that is electrically connected with ADC 150, to carry out the function corresponding to key-press status again.
For the relation between the voltage of the state that is illustrated more clearly in button and simulating signal SA, in following table one, list the voltage of the pairing output node 140 of some key-press status.Wherein, make RT=R1+R2+R3 and RT '=R1 '+R2 '+R3 ', and the voltage of output node 140 is tried to achieve according to Circuit theory.It should be noted that in the part of the listed key-press status key-press status that only embodiment was suitable for of table one for this reason.
Can clearly be seen that by table one, the voltage of the output node 140 that is produced when pressing the button more than two, different with the voltage of output node 140 when the next button.In addition, when different two buttons or the button more than two are pressed, output node 140 will produce different voltage levels.The circuit design mode of present embodiment can be so that button has the function of compound keys, and the state of button can be reflected on the voltage of output node 140.Therefore, present embodiment need only use single ADC I/O port, just can allow the microprocessor 160 of electronic installation 100 learn that button SW1-SW6 is that one key is pressed or the state that a plurality of button is pressed simultaneously, and then carry out function corresponding to this key-press status.
In addition, also can learn by table one, the magnitude of voltage of output node 140 except relevant with the state of button, also with each resistance string in the resistance value of resistance very direct relation is arranged.Therefore, in order to allow different key-press status produce different output voltage values, in order to avoid microprocessor 160 erroneous judgements, in the resistance of each resistance string, the resistance value summation of wantonly two resistance preferably is not equal to the resistance value of the arbitrary resistance in all the other resistance.Next, will be example with first resistance string 120 in the present embodiment, illustrate that in the application of reality the resistance value that will how to design the resistance in the resistance string just can reach above-mentioned requirement.
Table one: the voltage table of comparisons of the key-press status of first embodiment and output node 140.
| The state of button | The voltage of |
| Do not have and push any button | ????Vcc*[RT’/(RT+RT’)] |
| Push SW1 | ????Vcc*[RT’/(RT+RT’-R1)] |
| Push SW2 | ????Vcc*[RT’/(RT+RT’-R2)] |
| Push SW3 | ????Vcc*[RT’/(RT+RT’-R3)] |
| Push SW4 | ????Vcc*[(RT’-R1’)/(RT+RT’-R1’)] |
| Push SW5 | ????Vcc*[(RT’-R2’)/(RT+RT’-R2’)] |
| Push SW6 | ????Vcc*[(RT’-R3’)/(RT+RT’-R3’)] |
| Push SW1+SW2 | ????Vcc*[RT’/(R3+RT’)] |
| Push SW2+SW3 | ????Vcc*[RT’/(R1+RT’)] |
| Push SW1+SW3 | ????Vcc*[RT’/(R2+RT’)] |
| Push SW1+SW4 | ????Vcc*[(RT’-R1’)/(RT+RT’-R1-R1’)] |
| Push SW5+SW6 | ????Vcc*[R1’/(RT+R1’)] |
| Push SW1+SW2+SW3 | ????Vcc |
| Push SW4+SW5+SW6 | ????0 |
Referring again to Fig. 2 and table one.In order to simplify circuit design, the resistance value of three resistance that can be by making resistance string becomes geometric ratio progression relation, reaches to make in the resistance string, and the resistance value summation of wantonly two resistance is not equal to the requirement of the resistance value of another resistance.The common ratio of geometric progression preferably is 2.For instance, resistance value R1, the R2 of three resistance in first resistance string 120 and the ratio of R3 can be 1: 2: 4.So, when pressing keys SW1, SW2, SW3, SW1+SW2, SW2+SW3 and SW1+SW3, the magnitude of voltage that output node 140 is exported is all inequality.
In the same manner, if the resistance value of three resistance of second resistance string 130 is the geometric progression relation, then pressing keys SW4, SW5, SW6, SW4+SW5, SW5+SW6 and SW4+SW6, the magnitude of voltage that output node 140 is exported is all inequality.
If the resistance value in first resistance string 120 and second resistance string 130 is R1=R1 ', R2=R2 ' and R3=R3 ', so, then when nothing was pushed any button and pushed SW1+SW4, the magnitude of voltage that output node 140 is exported all equaled Vcc/2.In the same manner, when pushing SW2+SW5 or SW3+SW6, the magnitude of voltage that output node 140 is exported also can equal Vcc/2.Therefore, when the design composite key function, should avoid pushing simultaneously two and lay respectively in two resistance string, the button in parallel with the resistance of same resistance value.
Though present embodiment has 3 resistance with first resistance string 120, and it is that example is done explanation that second resistance string 130 has 3 resistance too, yet, according to spirit of the present invention, first resistance string 120 might not equate with the resistance number of second resistance string 130, also not necessarily to equal 3, as long as the number of all resistance of first resistance string 120 and second resistance string 130 sum total is more than or equal to positive integer 3, and first resistance string 120 and second resistance string 130 be minimum to comprise a resistance, can make the button of electronic installation have the function of compound keys.
In addition, present embodiment equates to be that example illustrates with the number of button with the total number of resistance.Yet according to spirit of the present invention, the number of button might not equate with the total number of resistance, as long as each button is in parallel with at least one resistance.That is to say that the sum of resistance can be more than or equal to the number of button.
Embodiment two
Please refer to Fig. 3, its expression is according to the part circuit diagram of the electronic device using multiple push keys of one second embodiment of the present invention.Electronic installation 200 comprises one first resistance string 220,230,3 button SW1-SW3 of one second resistance string, an output node 240, an analog-digital converter 250 and a microprocessor 260.
First resistance string 220 only contains a resistance, and the resistance value of this resistance is R1.Second resistance string 230 includes the resistance of two series connection, and its resistance value from top to bottom is R1 ' and R2 ' in regular turn.One end of first resistance string 220 is electrically connected with a high voltage Vcc, and the other end of first resistance string 220 then is connected with an end of second resistance string 230.The other end of second resistance string 230 is electrically connected with a ground voltage.
In addition, button SW1-SW3 is in parallel with resistance R 1 and R1 '-R2 ' respectively.When pushing different buttons, the pairing voltage of output node 240 meeting output key states is shown in following table two.The simulating signal SB that output node 240 is exported is handled this digital signal by the microprocessor 260 of electronic installation 200 after being converted to the digital signal of a correspondence by ADC 250 earlier again, to carry out the function corresponding to this key-press status.
It should be noted that in the listed key-press status of table two and only be the part of the key-press status that present embodiment was suitable for.Wherein, when resistance value R1 ' is not equal to resistance value R2 ', pressing keys SW2 and pressing keys SW3, the output voltage of output node 240 will be different.
Second embodiment is that with the difference of the first embodiment maximum number of the resistance in two resistance string is different.Can clearly be seen that by Fig. 2 first resistance string 120 and second resistance string 130 among first embodiment all have three resistance.That is the key circuit design in the electronic installation of first embodiment has symmetry.And can clearly be seen that by Fig. 3 first resistance string 220 among second embodiment only has a resistance, second resistance string 230 then has two resistance.That is the key circuit design in the electronic installation of second embodiment does not have symmetry, and the number of all resistance of two resistance string sum total is 3.
Therefore, as shown in the above description, no matter be symmetrical expression or the design of the key circuit of asymmetric, the number that needs only all resistance of two resistance string is summed up more than or equal to positive integer 3, just can be so that the button of electronic installation has the function of compound keys.
Table two: the voltage table of comparisons of the key-press status of second embodiment and output node 240.
| The state of button | The voltage of output node 240 |
| Do not have and push any button | ????Vcc*[(R1’+R2’)/(R1+R1’+R2’)] |
| Push SW1 | ????Vcc |
| Push SW2 | ????Vcc*[R2’/(R1+R2’)] |
| Push SW3 | ????Vcc*[R1’/(R1+R1’)] |
| Push SW2+SW3 | ????0 |
Compare with traditional electronic devices, key circuit in the electronic installation of the present invention designs except the number of the GPIO pin that can reduce needed microprocessor significantly, more just can be so that the button of electronic installation has the function of compound keys with single ADC I/O port.In addition, electronic installation of the present invention only need use a connecting line, can finish being electrically connected between the keyboard on being disposed at the microprocessor of system on the circuit board and being disposed at control circuit board.Use the electronic installation of a plurality of ADC I/O ports electronic installation of the present invention of comparing to have more to reduce and is connected the wire rod material cost with tradition, and the advantage of the degree of reduction electromagnetic interference (electromagnetic interference).
Claims (13)
1. electronic device using multiple push keys comprises at least:
One first resistance string has p resistance of connecting, and this first resistance string has one first end and one second end, and this first end is electrically connected with a high voltage;
One second resistance string, resistance with q series connection, this second resistance string has one the 3rd end and one the 4th end, this second end of this first resistance string is connected with the 3rd end of this second resistance string, the 4th end of this second resistance string is electrically connected with a low-voltage, the summation of p and q is M, and M is the positive integer more than or equal to 3;
N button, respectively this button is in parallel with at least one resistance; And
One output node is arranged between this first resistance string and this second resistance string, and this output node is in order to export a simulating signal, and the voltage of this simulating signal is corresponding to the state of these buttons.
2. electronic installation as claimed in claim 1, wherein, this electronic installation also comprises:
One analog-digital converter is electrically connected this simulating signal is changed back output one digital signal with this output node; And
One microprocessor is electrically connected with this analog-digital converter, and this microprocessor is in order to handle this digital signal, to carry out the function corresponding to these key-press status.
3. electronic installation as claimed in claim 1, wherein, p and q are the positive integer more than or equal to 1.
4. electronic installation as claimed in claim 1, wherein, this first resistance string only contains one first resistance, and this second resistance string contains one second resistance and one the 3rd resistance, and this second resistance and the 3rd resistance have different resistance values.
5. electronic installation as claimed in claim 1, wherein, p and q are the positive integer greater than 1, and p equates with q.
6. electronic installation as claimed in claim 5, wherein, this first resistance string contains one first resistance and one the 4th resistance, this second resistance string contains one second resistance and one the 3rd resistance, this first resistance links to each other with this first end of this first resistance string, this second resistance links to each other with the 3rd end of this second resistance string, and this first resistance and this second resistance have same resistance value, and the 3rd resistance and the 4th resistance have same resistance value.
7. electronic installation as claimed in claim 1, wherein, this first resistance string contains at least three resistance, and the resistance value summation of wantonly two resistance is not equal to the resistance value of the arbitrary resistance in all the other resistance.
8. electronic installation as claimed in claim 7, wherein, the resistance value of these resistance of this first resistance string is one first a geometric progression relation.
9. electronic installation as claimed in claim 8, wherein, the common ratio of this first geometric progression is 2.
10. electronic installation as claimed in claim 1, wherein, this second resistance string contains at least three resistance, and the resistance value summation of wantonly two resistance is not equal to the resistance value of the arbitrary resistance in all the other resistance.
11. electronic installation as claimed in claim 10, wherein, the resistance value of these resistance of this second resistance string is one second a geometric progression relation.
12. electronic installation as claimed in claim 11, wherein, the common ratio of this second geometric progression is 2.
13. electronic installation as claimed in claim 1, wherein, M equates with N.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410008030 CN1667551A (en) | 2004-03-08 | 2004-03-08 | Electronic device using multiple push keys |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410008030 CN1667551A (en) | 2004-03-08 | 2004-03-08 | Electronic device using multiple push keys |
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| Publication Number | Publication Date |
|---|---|
| CN1667551A true CN1667551A (en) | 2005-09-14 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410008030 Pending CN1667551A (en) | 2004-03-08 | 2004-03-08 | Electronic device using multiple push keys |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101907925B (en) * | 2009-06-08 | 2012-07-04 | 纬创资通股份有限公司 | Key circuit, electronic device and television using same, and testing method |
| WO2019037240A1 (en) * | 2017-08-24 | 2019-02-28 | 歌尔科技有限公司 | Key configuration method, key operation method, device and electronic apparatus |
| CN114035697A (en) * | 2021-11-26 | 2022-02-11 | 中国电子技术标准化研究院 | Low-radiation anti-electromagnetic-interference keyboard and mouse simulation device and method |
-
2004
- 2004-03-08 CN CN 200410008030 patent/CN1667551A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101907925B (en) * | 2009-06-08 | 2012-07-04 | 纬创资通股份有限公司 | Key circuit, electronic device and television using same, and testing method |
| WO2019037240A1 (en) * | 2017-08-24 | 2019-02-28 | 歌尔科技有限公司 | Key configuration method, key operation method, device and electronic apparatus |
| CN114035697A (en) * | 2021-11-26 | 2022-02-11 | 中国电子技术标准化研究院 | Low-radiation anti-electromagnetic-interference keyboard and mouse simulation device and method |
| CN114035697B (en) * | 2021-11-26 | 2023-10-03 | 中国电子技术标准化研究院 | Low-radiation anti-electromagnetic-interference keyboard and mouse simulation device and method |
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