JPH0541693A - Infrared ray space communication system - Google Patents

Abstract

PURPOSE:To obtain the infrared ray space communication system capable of simultaneous bi-directional transmission and reception because of the data communication for a computer and its peripheral equipment. CONSTITUTION:In the case of bi-directional communication between equipments 11 and 15, communication units 11 and 16 are established in each equipment. Transmission means 12 and 17, reception means 13 and 18, and microcomputers 14 and 19 are provided on the communication units 11 and 16. When the communication is performed using the communication carrier with the frequency higher than the conventional one, the time sharing bi-directional communication is performed between the communication units and the bi-directional simultaneous transmission and reception is performed between the equipments.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to infrared space communication, and more particularly to data communication between a computer and computer peripherals.

[0002]

2. Description of the Related Art In conventional infrared communication, in the case of a bidirectional remote controller, for example, half-duplex communication is performed between the bidirectional remote controller and the main body of a television or video. This is a method in which when one of them is transmitting, the other is receiving. Regarding the transmission / reception timing of the half-duplex communication method, first, the bidirectional remote control performs the first transmission and then enters the waiting state for reception, while the main body always starts from the waiting state for reception, and after receiving, the reception completion ( Or it was to send a signal). Further, the frequency of the carrier (basic pulse) for conventional communication is 30 to 40 KHz.

[0003]

In the case of communication between a remote controller and devices such as a television and a video, the remote controller mainly performs transmission, and for example, the television may receive the signal and change the channel. Therefore, the half-duplex communication method as described above may be used. However, for data communication between a computer and its peripherals, between a word processor and an electronic notebook, or between competitive game machines, it is not something that either one-sidedly transmits.
It can be considered that the loads of transmission and reception between the devices are almost equal. Therefore, when communication is performed between such devices by the half-duplex communication method, the timings for transmitting and receiving between the two communication devices are not established, and therefore the mutual transmission signals interfere with each other and the reception signals are received. There was an inconvenience that an error occurred in the created data. It is an object of the present invention to solve such a problem and to provide an infrared space communication system capable of bidirectional simultaneous transmission / reception between device bodies without causing interference between communication devices.

[0004]

In order to achieve the above object, the infrared space communication system of the present invention controls a transmitting means, a receiving means, the transmitting means and the receiving means, and a transmission received from a device body. And a control means for converting the data into short-term data and sending the data to the transmitting means, and converting the data received by the receiving means from another device into the long-term data and sending the data to the device body. Units are provided in both devices so that bidirectional simultaneous transmission / reception is possible between the device bodies. Further, at the start of bidirectional communication between the devices, initial communication for timing of transmission / reception is performed.

[0005]

By doing so, although time-divisional bidirectional communication is performed between the communication units, bidirectional transmission / reception can be realized at the same time from the viewpoint of the device main bodies. Also, in the case of bidirectional infrared space communication, it is necessary to decide which is the sender first, but there is no problem because it is decided by performing initial communication when starting communication. ..

[0006]

Embodiments of the present invention will now be described with reference to the drawings.
explain. FIG. 1 is a block diagram showing a communication device embodying the present invention. The device 10 is provided with a communication unit (hereinafter referred to as “unit”) 11, and the device 15 is provided with a unit 16. The unit 11 of the device 10 includes a light emitting element 12 such as an LED, a light receiving element 13 such as a photodiode, and a microcomputer 14, and the unit 16 of the device 15 similarly includes a light emitting element 17, a light receiving element 18, and a microcomputer 19. It is configured. Then, the transmission data transmitted by the light emitting element 12 of the unit 11 of the device 10 is received by the light receiving element 18 of the unit 16 of the device 15, and the transmission data transmitted by the light emitting element 17 of the unit 16 of the device 15 is transmitted by the device 10. The light is received by the light receiving element 13 of the unit 11. Consider a case where the device 10 wants to send certain data to the device 15. First, the device 10 sends the data to be transmitted to the unit 11. The microcomputer 14 of the unit 11 converts the received data into optical data and then transmits the optical data by the light emitting element 12. machine
In the unit 16 of 15, the microcomputer 19 receives the data through the light receiving element 18, reconverts the data, restores the original data, and then sends the data to the device 15. The transmission from the device 15 to the device 10 is similarly performed. The transmissions from units 11 and 16 are controlled so that they do not occur simultaneously. This is because infrared rays of the same wavelength are usually used for communication between the devices, and if they are sent at the same time, interference will still occur. However, in the communication system of the present embodiment, the frequency of the communication carrier is set as high as about 500 KHz, and since the data is also converted, the time required for transmitting and receiving the same amount of data is shortened compared to the conventional case. From the viewpoint of the main devices (10 and 15), it seems that simultaneous bidirectional communication is being performed.

The signals used for actual communication will be described below. FIG. 2A shows a communication carrier in this embodiment. As shown in the figure, the period of this basic pulse is 2.17 μs, that is, its frequency is about 500.
The frequency is KHz, which is 10 times or more higher than the conventional frequency. Eight pulses of this basic pulse are set to T1, and T1 is used to form bits of 0 and 1 as shown in (b). In the case of actual data communication, (b)
The signal shown in is used.

FIG. 3 shows signals used in initial communication described later. (A) is the same carrier as (a) of FIG. 2, and 16 pulses of this basic pulse are set to T2,
As shown in (b), T2 is used to generate the T3 signal. The T4 signal actually used in the initial communication is composed of, for example, the T3 signal for 11 times.

FIG. 4 shows a timing chart of initial communication performed at the start of communication. This is the sending side (hereinafter “main side”) of the first communication between two devices.
(Also referred to as "subordinate side") and the receiving side (hereinafter also referred to as "subordinate side") (sending / receiving are sequentially switched after the first transmission / reception is completed), and when the power is turned on, actual data communication is performed. It will be held once before. Normally, the power is turned off first
The device that has been N becomes the transmission side. A description will be given along the timing chart. First, it is assumed that the power of the device 10 is turned on. It waits for reception for 3 seconds after the power is turned on. If there is no reception during this time, the device 10, as a temporary transmission side, starts transmitting the T4 signal. While the device 10 is waiting for reception, the power of the device 15 is turned on, and similarly, the device 15 is in a reception waiting state.
The device 15 receives the T4 signal from the device 10 during the waiting 3 seconds, but returns the T4 signal after the reception, and the receiving side of the device 15 is confirmed. After transmitting the T4 signal, the device 10 once enters the reception mode and waits for a reply of the T4 signal from the device 15 (4.4 ms). Here, after receiving the T4 signal, transmission and reception of the T4 signal are repeated three times, and when the reply of a total of four times can be confirmed, the transmission side of the device 10 is determined. The four T4 signals are transmitted as slightly different signals. In the present embodiment, specifically, the signal is one in which the number of carrier pulses is changed, but the pulse duty may be changed. In this way, if the T4 signal is changed if it is the same signal, for example, if the device 15 cannot receive the first transmission from the device 10, the T4 signal is transmitted as the transmitting side. This is because the device 10 side does not know that it is not a transmission response and both sides recognize it as the transmission side, and an error occurs during the subsequent data communication. If different signals are used, the signal transmitted by the device 15 and the signal returned by the device 15 do not match, so that the user can recognize that he is not the transmitting side.

In the initial communication, if a reception error occurs in the middle of the process, the process returns to the reception waiting for 3 seconds immediately after the power is turned on and restarts. Also, if you do not receive a reply after waiting 4.4 ms (for example, if the power of the other device is not turned on) after waiting for 3 seconds, send the T4 signal again and receive a reply. Repeat until there is.

FIG. 5 shows a timing chart of actual data communication. In the figure, device 10 is the transmitting side and device 15
Is the receiving side. Here, the receiving side synchronizes with the rising edge (S1 in the figure) of the data output of the transmitting side for each transmission. Specifically, when data is received from the transmitting side (S2), synchronization is established. This is because the devices 10 and 15 are usually equipped with a microcomputer.
Since the microcomputers 14 and 19 are also provided in 11 and 16,
This is because, when operating with each clock, data may be lost due to variations in the clocks. Furthermore, the reason why each transmission / reception is performed is to prevent the deviation from increasing in proportion to the amount of data when a large amount of data is transmitted. One transmission is performed with 8-bit data, and a reply to it is normally 8-bit read 2-bit pin data (described later).
Is added. This transmission / reception is performed for 3.328 ms as shown in the figure.

A description will be given along the timing chart. When the initial communication is completed and the devices of the transmission side and the reception side are determined, the transmission side actually starts data transmission. Here, it is assumed that the device 10 is the transmitting side and the device 15 is the receiving side. The timing chart shows the time when data of 8 bits is output from the device 10 to the unit 11 (3.3.
28 ms) is a division, but the transmission side and the reception side are synchronized with each other at each time as described above.
At timing 1, the device 10 outputs data 0 of 8 bits to the unit 11. In the figure, Δ represents data conversion by the unit, but data 0 is converted to optical data for transmission at timing 1. At timing 2, the device
The data 1 is output from the unit 10 to the unit 11, and the unit 11 transmits the data 0 converted at the previous timing and then converts the data 1. On the other hand, the unit of the receiving device 15
The 16 receives the data 0, and at the same timing 2, the optical data is converted to the original data. Timing 3
Then, the device 10 outputs the data 2 to the unit 11, the unit 11 transmits the data 1 converted at the previous timing, receives the data from the device 15 side, and then converts the data 2. On the other hand, the unit 16 of the device 15 on the receiving side receives the data 1 and transmits (replies) the data 0 received at the previous timing, and then at the same timing 3, the optical data is changed from the optical data to the original data with respect to the data 1. Is being converted.
Also, at the same timing 3, the data 0 converted at the previous timing is sent to the device 15.

From timing 4 onward, the procedure is the same as that of timing 3. The transmission side unit transmits the data output from the device at the timing one before and the reply data of the data transmitted at the timing two before. Is received and the output data is converted at that timing. Also,
The receiving unit receives the data from the sending side,
After returning the data received at the previous timing, while converting the data received at that timing, 1
The converted data is sent to the device at the previous timing. As described above, the transmission and reception between the unit 11 and the unit 16 is half-duplex communication in which one is a transmission and the other is a reception, but the transmission time and the reception time are shortened by increasing the frequency of the carrier. In addition, data conversion can be performed within each timing of performing them.
On the other hand, the device 10 and the unit 11, and the device 15 and the unit 16
Since data is continuously transmitted and received between the two devices, it is equivalent to performing double communication from the viewpoint of the devices 10 and 15 (pseudo double communication).

The receiving side transmits (replies) the received data after completing the reception of the data in order to inform the transmitting side of whether or not the data is correctly received. Although not written in the timing chart, the sending side checks if the returned data matches the sent data. The unit can perform transmission and reception, and data conversion at one timing because the frequency of the communication carrier is higher than before, so the time required for transmission and reception is shorter, This is one factor that enables bidirectional simultaneous transmission and reception.

In the above-described data communication, the slave device 15 may have a reading deviation depending on the data speed. Timing charts of this reading shift are shown in (a) and (b) of FIG. (A) is when the data speed is slow, and (b) is when the data speed is fast. • is the sample timing point. In the figure, S3 is the timing for ending the reading of data once, that is, the transmission timing point to the main unit.
In the case of (a), since the transmission timing is delayed if all 8 bits of data are read, 7 bits from 9-0 to 9-6 and 2 bits of pin data read earlier are read.
9 bits are transmitted and timing is adjusted, then 9-7 is read at the next reading timing and transmitted. Further, in the case of (b), the transmission timing will be accelerated only by reading the 8-bit data,
Waiting for the transmission timing causes the data of 1 bit of 10-0 data to be missed. Therefore, the next 1 bit of 10-0 data is also read and 11 bits of data 9 bits and pin data 2 bits are read.
Transmit t to adjust the timing. With this processing, even if the data speed changes due to the clock timing or the like, no data is lost during reception.

The above pin data will be described. Pin data consists of 2 bits and is a unit (11 and 16)
The information of a certain terminal indicates the state of transmission / reception, that is, the current transmission mode or reception mode.
The pin data of this unit can be read using data 8bi
This is carried out at the same time as the reading of t, and at the time of replying the data, the pin data of 2 bits and the data of 8 bits (7-9 bits if there is a deviation) are transmitted. This is for checking the control of transmission and reception during data communication.

FIG. 7 shows a flowchart of a main routine for controlling the entire communication. This routine and the initial communication routine described below are routines executed by the microcomputers (14 and 19 in FIG. 1) provided in the units of both devices that perform communication. When this routine starts in step # 100, power ON reset processing is performed in step # 105, and then in standby mode waiting for interrupt in step # 110, waiting for interrupt. At step # 200, an interrupt is generated by turning on the power, and the power-on interrupt routine is activated. Here, it is checked in step # 205 whether the initial communication is completed, and if it is completed, the procedure proceeds to step # 215, and if not completed, the step # 210 is performed.
To execute the initial communication routine. After the initial communication is completed, actual data communication is performed in step # 215.
In step # 220, it is checked whether an error has occurred. If there is no error, the process returns to step # 215 to repeat the data communication.
When it is determined in step # 220 that an error has occurred, the error processing routine is executed in step # 225, the process returns to step # 205, and the initial communication is performed again. Here, the description of the error processing routine is omitted. Although omitted in the figure, the execution of the main routine is stopped when an interrupt due to power OFF occurs.

FIG. 8 shows a flowchart of the initial communication routine of step # 210 of FIG. As described above, this is a routine that is performed prior to the actual data communication and determines the master-slave relationship (transmission side-reception side) between the communicating devices. When this routine starts in step # 300, first, in step # 305, a timer for 3 seconds is set. In step # 310, it is determined whether there is a reception. If there is a reception, proceed to step # 350, and if not, step # 315.
Check to see if 3 seconds have passed. If it has not elapsed, the process returns to step # 310 to wait for reception. If there is no reception after 3 seconds, the T4 signal is transmitted in step # 320. Step
In # 325, see if there is a reply from the device of the communication partner. If there is no reply, it returns to step # 305 and waits for reception for 3 seconds again. If there is a reply, check whether the T4 signal transmitted in step # 330 has been returned. If the transmitted signal does not return, return to step # 305 and start over. If the T4 signal is confirmed in step # 330, the communication is confirmed four times in step # 335.
If the 4 signals have been transmitted / received, if not yet, return to step # 320 to transmit the T4 signal. If the transmission / reception of 4 times has been completed, the main side is recognized in step # 340, and step # 340 is executed. Return to the main routine at 345. If there is a reception during the reception waiting for the first 3 seconds, the process proceeds to step # 350. In step # 350, it is confirmed whether the received signal is the T4 signal. If it is not the T4 signal, a data error has occurred, and the process returns to step # 305. If T4 signal can be confirmed, step
Return T4 signal with # 355. In step # 360, it is checked whether or not the T4 signal has been received and returned four times as a communication confirmation. If not yet, in step # 365, it is checked whether there has been a reception. If there is a reception, the process returns to step # 350, and if there is no reception, the process returns to step # 305. If the reception and transmission of the T4 signal have been completed four times, the slave side is recognized in step # 370, and the process returns to the main routine in step # 345.

[0019]

As described above, according to the present invention,
Two-way communication between devices is possible, and cableless can be achieved between devices that are currently performing two-way communication using cables etc., so wiring work is saved and compared to communication using radio waves. You can also reduce costs.

[Brief description of drawings]

FIG. 1 is a block diagram of a communication device embodying the present invention.

FIG. 2 is a diagram showing signals used in data communication.

FIG. 3 is a diagram showing signals used in initial communication.

FIG. 4 is a diagram showing a timing chart of initial communication.

FIG. 5 is a diagram showing a timing chart of data communication.

FIG. 6 is a diagram showing a timing of data reading deviation.

FIG. 7 is a diagram showing a flowchart of a main routine of control of overall communication.

FIG. 8 is a diagram showing a flowchart of an initial communication routine.

[Explanation of symbols]

 10 Equipment 11 Communication unit 12 Light emitting element 13 Light receiving element 14 Microcomputer 15 Equipment 16 Communication unit 17 Light emitting element 18 Light receiving element 19 Microcomputer

Claims (2)

[Claims] 1. A method of performing spatial communication between two devices by infrared rays, which controls a transmitting means, a receiving means, the transmitting means and the receiving means, and transmits the transmission data received from the equipment body in a short time. And a control unit for converting the data from another device received by the receiving unit to a device for a long time and transmitting the data to the device body. Infrared space communication system, which is installed in the device and is capable of bidirectional simultaneous transmission and reception between device bodies. 2. The infrared space communication system according to claim 1, wherein at the start of bidirectional communication between the devices, initial communication for performing transmission / reception timing is performed.