JP5005442B2 - Input device using rotary dip switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an input device using a rotary dip switch, capable of effectively utilizing the I/O port of a control IC 11 and reducing a mounting area on a substrate. <P>SOLUTION: In this input device, a key matrix circuit 31 connects row lines H1-H5 through a noise countermeasure circuit 32 to the input terminals R1-R5 of a control IC 33, executes pull-up to a power supply voltage VDD through a resistor R, and further connects the row lines H1-H4 to the terminals A, E, B and D of the rotary dip switch 34 through diodes D1-D4 in a forward direction. The control IC 33 supplies scanning signals outputted from open drain output terminals C1-C5 to the column lines V1-V4 of the key matrix circuit 31 and the common terminal C of the rotary dip switch 34, fetches in the input information of the input terminals R1-R5, and discriminates the operation contents of the key matrix circuit 31 and the setting contents of the rotary dip switch 34 by the timing of the scanning signals and the input information. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an input device using a rotary dip switch used in, for example, a commercial wireless terminal.

  Conventionally, in business wireless terminals such as portable wireless devices, a rotary dip switch (rotary switch) is generally used as a communication channel selection switch (see, for example, Patent Document 1). The rotary dip switch has a fixed position for each rotation angle, and even if the switch state is difficult to see, the user can determine the communication channel selection state by counting the fixed position state when the switch is rotated. There is an advantage of being able to grasp. The rotary dip switch has, for example, a cord system as shown in FIG. 4 and includes a plurality of cord terminals, for example, terminals A, E, B, D and a common terminal C, and a mechanical fixed position when the operation shaft is turned. The state changes from 0 to 15, for example, and 16 communication channels can be selected. Each of these communication channels is set to a different value for the transmission / reception frequency.

  The relationship between the terminals A, E, B, and D and the position states of the 16 channels is set as shown in FIG. 4. For example, when the position state is “2”, the terminals A and E are The switch is electrically connected to the common terminal C, and the terminals B and D are open to the common terminal C. In FIG. 4, black circles indicate that the terminals A, E, B, and D are in conduction with the common terminal C.

  Next, a conventional data capturing method in the rotary dip switch will be described. FIG. 5 is a circuit configuration diagram of a conventional input device used for a commercial wireless terminal or the like.

  In FIG. 5, 10 is a rotary dip switch input circuit unit for selecting a communication channel, 20 is a key matrix circuit unit for performing key input, and 11 is common to the rotary dip switch input circuit unit 10 and the key matrix circuit unit 20. Control IC.

  In the rotary dip switch input circuit unit 10, input terminals I / O 1 to I / O 4 that are general-purpose ports of the control IC 11 are connected to terminals A, E, B, and D of the rotary dip switch 13 via the noise countermeasure circuit 12. The Each connection line between the noise countermeasure circuit 12 and the terminals A, E, B, and D of the rotary dip switch 13 is pulled up to the power supply voltage VDD via the resistor R. Further, the common terminal C of the rotary dip switch 13 is grounded (GND) and held in a low level state.

  The rotary dip switch input circuit unit 10 configured as described above has terminals A, E, B, and D depending on the connection state between the terminals A, E, B, and D of the rotary dip switch 13 and the common terminal C. The state becomes a high level or a low level, and this state becomes input information of the control IC 11. For example, when the rotary dip switch 13 is in the state “2” of the code system shown in FIG. 4, the terminal A and the terminal E are electrically connected to the common terminal C inside the switch and become a low level state. , D are pulled up to the power supply voltage VDD, so that they are in a high level state. By determining and controlling the low level or high level state of the terminals A, E, B, and D as input information of the control IC 11, the fixed position state of the rotary dip switch 13 can be grasped and controlled. Make a selection.

  The key matrix circuit unit 20 includes a key matrix circuit 21 in which, for example, push switches S1 to S20 are arranged in a matrix of 5 rows and 4 columns. The row lines of the key matrix circuit 21 are connected to the input terminals R1 to R5 of the control IC 11 via the noise countermeasure circuit 22 and are pulled up to the power supply voltage VDD via the resistors R, respectively. The column lines of the key matrix circuit 21 are connected to the open drain output terminals C1 to C4 of the control IC 11 via the noise countermeasure circuit 22.

  As shown in the timing chart of FIG. 6, the open drain output terminals C1 to C4 of the control IC 11 change in impedance at timings t1, t2, t3, and t4, and at timings t1, t2, t3, and t4. It goes into a low state and a high state at other timings. That is, the control IC 11 takes in the data input by using the software control unit for the key matrix circuit 21 as a scanning type.

When the push switches S1 to S20 are pressed, the key matrix circuit unit 20 changes the row line signal to a low level at the timing t1 to t4, and this state is input to the control IC 11 as input information. Input to terminals R1 to R5. The control IC 11 determines which push in the key matrix circuit unit 20 from the timing t1, t2, t3, t4 when the impedance of the open drain output terminals C1 to C4 changes to a low level state and the input information of the input terminals R1 to R5. It is determined whether the switches S1 to S20 are pressed. For example, when the push switch S2 is operated, the row line connected to the input terminal R1 of the control IC 11 becomes a low level state at the timing t3, so that the control IC 11 is connected to the row line of the input terminal R1 and the open drain. It can be determined that the push switch S2 at the intersection of the output terminal C3 and the column line is pressed.
JP 2006-250666 A

  According to the above conventional input device, the control IC 11 can perform channel selection by grasping the fixed position state of the rotary dip switch 13 from the input information of the input terminals I / O1 to I / O4. Which push switches S1 to S20 are pressed can be determined from the input information of R1 to R5 and the timing of the scanning signals output from the open drain output terminals C1 to C4.

  However, since the general-purpose I / O ports of the control IC 11 are limited, it is necessary to use as few ports as possible. Further, since external input circuits such as the rotary dip switch 13 and the key matrix circuit 21 cannot be shielded, the noise countermeasure circuits 12 and 22 must be installed for each wiring. As a result, there is a problem that not only the wiring restriction on the substrate is imposed, but also the mounting area and the number of parts are increased.

  The present invention has been made to solve the above-described problems, and can be used effectively for the I / O port of the control IC 11, and the rotary dip switch can reduce the number of noise countermeasure circuits and reduce the mounting area on the board. An object of the present invention is to provide an input device using the.

The present invention is a rotary dip switch that includes a key matrix circuit in which a plurality of switches are arranged in a matrix, a plurality of terminals and a common terminal, and outputs a code signal according to the connection state between the plurality of terminals and the common terminal. Scanning signals at different timings sequentially to the diodes provided between the row line of the key matrix circuit and the plurality of terminals of the rotary dip switch, and the column line of the key matrix circuit and the common terminal of the rotary dip switch, respectively. And an input device using a rotary dip switch comprising a control unit that captures a signal generated in a row line of the key matrix circuit ,
Wherein the control unit, said key matrix circuit and the rotary give DIP switch scan signal timing and discriminating means for discriminating the operation contents and settings of the rotary DIP switch of the key matrix circuit by a signal generated row lines of the key matrix circuit And a frequency setting means for variably setting the frequency of the scanning signal according to the reception frequency selected by the portable radio when the input device using the rotary dip switch is applied to the portable radio. It is characterized by that.

  According to the present invention, by incorporating a rotary dip switch in the key matrix circuit unit, an input terminal for capturing key matrix data is used without providing a dedicated input terminal for capturing data of the rotary dip switch in the control unit. Thus, the data of the rotary dip switch can be taken into the control unit, the number of input terminals can be reduced, the circuit configuration can be simplified, and the mounting area on the substrate can be reduced.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a circuit configuration diagram of an input device using a rotary dip switch according to an embodiment of the present invention. In FIG. 1, reference numeral 31 denotes a key matrix circuit. For example, push switches S1 to S20 are arranged in a matrix of 5 rows and 4 columns. The row lines H1 to H5 of the key matrix circuit 31 are connected to the input terminals R1 to R5 of the control unit, for example, the control IC 33 through the noise countermeasure circuit 32 and are pulled up to the power supply voltage VDD through the resistors R, respectively. . As the noise countermeasure circuit 32, for example, a low pass filter configured by combining a choke coil L and a capacitor C is used.

  In the key matrix circuit 31, among the row lines H1 to H5, the row lines H1 to H4 are connected to the terminals A, E, B, and D of the rotary dip switch 34 through the diodes D1 to D4 in the forward direction. . The diodes D1 to D4 are provided so that the level changes of the row lines H1 to H5 in the key matrix circuit 31 do not affect each other, and details thereof will be described later. The rotary dip switch 34 is composed of, for example, four terminals A, E, B, D and a common terminal C like the conventional rotary dip switch, and has, for example, the code system shown in FIG. You can choose.

  The column lines V1 to V4 of the key matrix circuit 31 are connected to the open drain output terminals C1 to C4 of the control IC 33 via the noise countermeasure circuit 32. The control IC 33 is provided with another open drain output terminal C5 in addition to the open drain output terminals C1 to C4. The open drain output terminal C5 is connected to the common terminal C of the rotary dip switch 34 by a signal line 35. Connected.

  The control IC 33 includes a scanning type software control unit for the key matrix circuit 31 and a scanning type software control unit for the rotary DIP switch 34. The scanning type soft control unit for the key matrix circuit 31 in the control IC 33 outputs scanning signals from the open drain output terminals C1 to C5, and the impedance of the open drain output terminals C1 to C5 as shown in FIG. Is changed in a pulse manner so as to be in a low state at timings t1, t2, t3, t4, and t5, and in a high state at other timings, and scanning timings t1, t1 of the open drain output terminals C1 to C4 are changed. The operation content of the key matrix circuit 31 is determined from t2, t3, t4 and the input information of the input terminals R1 to R5. The software controller for the key matrix circuit 31 has a function of changing the scanning time of the open drain output terminals C1 to C5 in accordance with the transmission / reception frequency selected by the wireless device, as will be described in detail later. .

  Further, the scanning type soft control unit for the rotary dip switch 34 in the control IC 33 grasps the fixed position state of the rotary dip switch 34 from the scanning timing t5 of the open drain output terminal C5 and the input information of the input terminals R1 to R4. Perform channel selection.

  Next, a data capturing operation of the input device according to the above embodiment will be described with reference to a timing chart shown in FIG. 2A is a timing chart showing the timing of scanning signals output from the open drain output terminals C1 to C4 of the control IC 33, and FIGS. 2B to 2D are diagrams for explaining the data capturing operation of the control IC 33. FIG. It is a timing chart.

  FIG. 2B shows the push switch of the key matrix circuit 31 when the rotary dip switch 34 is in the state “1” of the code system shown in FIG. 4, that is, the terminal A is electrically connected to the common terminal C inside the switch. The operation | movement timing chart in input terminal R1-R5 of control IC33 when S2 is pushed is shown.

  When the push switch S2 of the key matrix circuit 31 is pressed while the rotary dip switch 34 is in the state “1”, the input terminal R1 of the control IC 33 is in a low level state together with the open drain output terminal C3 at the timing t3. Therefore, the control IC 33 can determine that the push switch S2 provided between the row line H1 and the column line V3 of the key matrix circuit 31 is pressed. When the terminal A of the rotary dip switch 34 is electrically connected to the common terminal C, only the input terminal R1 of the control IC 33 is in a low level state at the timing t5, so that the software control unit for the rotary dip switch 34 is By recognizing the state of the input terminal R1 by time division, it can be determined that the rotary DIP switch 34 is in the state “1”.

  Further, when the push switch S2 of the key matrix circuit 31 is pressed when the rotary dip switch 34 is in the state “2” (terminals A and E are in conduction with the common terminal C), as shown in the timing chart of FIG. At the timing of t3, the input terminal R1 of the control IC 33 becomes a low level state, and at the timing of t5, the input terminals R1 and R2 of the control IC 33 become a low level. The control IC 33 determines that the push switch S2 of the key matrix circuit 31 has been pressed when the input terminal R1 of the control IC 33 becomes a low level state at the timing t3, and the control IC 33 performs the control IC 33 at the timing t5. When the input terminals R1 and R2 become low level, it can be determined that the rotary dip switch 34 is in the state “2”.

  When the push switch S2 of the key matrix circuit 31 is pressed when the rotary dip switch 34 is in the state “5” (terminals A, E, and B are electrically connected to the common terminal C), the timing chart of FIG. As shown, the input terminal R1 of the control IC 33 becomes a low level at the timing t3, and the input terminals R1, R2, and R3 of the control IC 33 become the low level at the timing t5. The control IC 33 determines that the push switch S2 of the key matrix circuit 31 has been pressed when the input terminal R1 of the control IC 33 becomes a low level state at the timing t3, and the input of the control IC 33 at the timing t5. When the terminals R1, R2, and R3 are at a low level, it can be determined that the rotary dip switch 34 is in the state “5”.

  In the example of FIGS. 2B to 2D, the operation when the push switch S2 of the key matrix circuit 31 is pressed has been described. However, the same applies when other push switches are pressed. Can be determined. Further, even when the push switches S1 to S20 are not pressed, the state of the rotary dip switch 34 from “0” to the state of the rotary dip switch 34 is determined from the scanning timing t5 of the open drain output terminal C5 of the control IC 33 and the input information of the input terminals R1 to R4. “15” can be discriminated.

  As described above, the control IC 33 can determine the key operation of the key matrix circuit 31 from the timings t1 to t4 by the scanning of the open drain output terminals C1 to C4 and the input information of the input terminals R1 to R5, and the open drain output terminal C5. The channel selection can be performed by grasping the states “0” to “15” of the rotary dip switch 34 from the scanning timing t5 and the input information of the input terminals R1 to R4.

  Next, the operation of the diodes D1 to D4 provided between the row lines H1 to H4 of the key matrix circuit 31 and the terminals A, E, B, and D of the rotary dip switch 34 will be described.

  When the diodes D1 to D4 are provided as shown in FIG. 1, for example, when the rotary DIP switch 34 is set to the state “2” (terminals A and E are in conduction with the common terminal C), the key matrix is used. If the push switch S2 of the circuit 31 is pressed, the input terminal R1 of the control IC 33 goes to the low state at the timing t3 and the input terminal R1, at the timing t5, as shown in the timing chart of FIG. R2 is in the low state, and the control IC 33 can normally determine the operation of the push switch S2 and the state “2” of the rotary dip switch 34.

  However, if the diodes D1 to D4 are not present, for example, when the push switch S2 of the key matrix circuit 31 is pressed while the rotary dip switch 34 is set to the state “2”, the rotary dip switch 34 is turned on at the timing t3. As the terminal A goes to the low state, the terminal E conducting to the terminal A and the row line H2 of the key matrix circuit 31 also go to the low state. As a result, even if the push switch S6 of the key matrix circuit 31 is not pressed, the input terminals R1 and R2 of the control IC 33 are in a low state at the timing of t3, and the control IC 33 indicates that the push switches S2 and S6 are pressed. Misunderstood. In order to prevent such erroneous recognition of the control IC 33, diodes D1 to D4 are provided so that the level changes of the row lines H1 to H5 in the key matrix circuit 31 do not affect each other.

  The input device according to the present invention incorporates the rotary dip switch 34 into the key matrix circuit unit as shown in the above embodiment and simplifies the circuit configuration by using the rotary dip switch data capturing method as a scanning type. When implemented in a wireless terminal, there is a possibility of affecting the performance of the wireless device depending on the scanning time. In particular, when the harmonic component of the scanning signal is the same as the reception frequency, problems such as deterioration in reception sensitivity can be considered. For this reason, in the present embodiment, the software control unit provided in the control IC 33 has a function of changing the scanning time of the open drain output terminals C1 to C5 according to the transmission / reception frequency selected by the wireless device. The performance degradation of the is prevented.

  Hereinafter, the processing operation when the scanning time of the open drain output terminals C1 to C5 of the control IC 33 is set according to the transmission / reception frequency selected by the wireless device will be described with reference to the flowchart shown in FIG.

  The software control unit provided in the control IC 33 checks whether or not the radio transmission / reception frequency is selected as shown in step A1 of FIG. When the transmission / reception frequency is selected, the selected transmission / reception frequency is fs, the reference scanning time for the open drain output terminals C1 to C5 is Ts, the timer minimum setting time is Tn, and the integer N is “0” (step A2). Then, the remainder M is obtained by dividing the transmission / reception frequency fs by the scanning frequency (1 / Ts) (step A3).

  Next, it is determined whether or not the remainder M is “0” (step A4). That is, it is determined whether the harmonic component of the scanning frequency (1 / Ts) is the same as the transmission / reception frequency fs. The remainder M is “0” (the harmonic component of the scanning frequency (1 / Ts) is the transmission / reception frequency fs). If it is the same, the value of N is incremented by “+1” (step A5), and the process of “Ts = (Ts + N * Tn)”, that is, the value obtained by adding the timer minimum setting time Tn to the scanning time Ts is set as the scanning time Ts. (Step A6). Thereafter, returning to step A3, the remainder M is obtained by dividing the transmission / reception frequency fs by the scanning frequency (1 / Ts) using the scanning time Ts set in step A6.

  When it is determined in step A4 that the remainder M is not “0”, the scanning time of the open drain output terminals C1 to C5 is set to Ts (step A7).

  By setting the scanning time Ts of the open drain output terminals C1 to C5 as described above, it is possible to prevent the harmonic component of the scanning noise due to the scanning signal from being the same as the reception and transmission frequency, and to cause adverse effects such as deterioration in reception sensitivity. Can be prevented.

  According to the above embodiment, since the rotary dip switch 34 is incorporated in the key matrix circuit section and the rotary dip switch data fetching method is a scanning type, a dedicated input terminal for fetching data of the rotary dip switch 34 is provided in the control IC 33. Without being provided, the data of the rotary dip switch 34 can be taken into the control IC 33 by using the input terminals R1, R2,... For taking the key matrix data, and the number of input terminals and the number of noise countermeasure circuits can be reduced. The configuration can be simplified and the mounting area on the substrate can be reduced.

  In the present embodiment, the software control unit provided in the control IC 33 has a function of changing the scanning time of the open drain output terminals C1 to C5 in accordance with the transmission / reception frequency selected by the wireless device. Even when applied to a commercial wireless terminal, it is possible to prevent the harmonic component of the scanning noise caused by the scanning signal from becoming the same as the reception / transmission frequency, and to prevent adverse effects such as deterioration in reception sensitivity.

  In the above embodiment, the case where the communication channel is selected by the rotary dip switch 34 has been described. However, even when the communication channel and the system are selected by the rotary dip switch 34, the embodiment can be implemented in the same manner. It is.

  Further, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying constituent elements without departing from the scope of the invention in the implementation stage.

It is a circuit block diagram of the input device using the rotary dip switch which concerns on one Embodiment of this invention. It is a timing chart for explaining the switch operation of the key matrix circuit and the operation of fetching the setting contents of the rotary dip switch. 4 is a flowchart showing an operation in the case where the scanning time of the open drain output terminal of the control IC is set according to the transmission / reception frequency selected by the wireless device in the embodiment. It is a figure which shows the code system example of a rotary dip switch. It is a circuit block diagram of the input device using the conventional rotary dip switch. It is a timing chart which shows the scanning signal with respect to the key matrix circuit of the input device using the conventional rotary dip switch.

Explanation of symbols

  S1 to S20 ... push switches, R1 to R5 ... control IC input terminals, C1 to C5 ... control IC open drain output terminals, D1 to D4 ... diodes, H1 to H5 ... key matrix circuit row lines, V1 to V4 ... Column line of key matrix circuit 31... Key matrix circuit 32. Noise countermeasure circuit 33. Control IC 34. Rotary dip switch 35.

Claims (1)

A key matrix circuit in which a plurality of switches are arranged in a matrix, a rotary dip switch that includes a plurality of terminals and a common terminal, and outputs a code signal according to a connection state between the plurality of terminals and the common terminal, and the key Applying scanning signals to the diodes respectively provided between the row lines of the matrix circuit and the plurality of terminals of the rotary dip switch, and the column lines of the key matrix circuit and the common terminal of the rotary dip switch at different timings, An input device using a rotary dip switch comprising a control unit that captures a signal generated in a row line of a key matrix circuit ,
Wherein the control unit, said key matrix circuit and the rotary give DIP switch scan signal timing and discriminating means for discriminating the operation contents and settings of the rotary DIP switch of the key matrix circuit by a signal generated row lines of the key matrix circuit And a frequency setting means for variably setting the frequency of the scanning signal according to the reception frequency selected by the portable radio when the input device using the rotary dip switch is applied to the portable radio. An input device using a rotary dip switch.

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