JPH09321824A - Infrared ray radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continue communication while revising part or all communication parameters during communication between infrared ray radio communication equipments. SOLUTION: A control means 2 converts transmission data into a serial signal in a universal asynchronous receiver and transmitter (UART) 5 and an encoder 8 drives a driver 9 to light a light emitting device 10 and communication is conducted according to a predetermined communication parameter. On the other hand, a signal from an opposite equipment is received by a light receiving device 11 and a comparator 13 compares the level with a prescribed signal level and the result is decoded by a decoder 14 and the control means 2 converts the signal into a parallel signal in the UART 5 and then read. When no reply signal is sent from the opposite equipment due to occurrence of a communication error during communication, the decision is made again and the communication parameter is set and the maintenance is continued.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared wireless communication device equipped with infrared wireless communication means.

[0002]

2. Description of the Related Art IrDA (Inf
This is a communication method that is rapidly becoming popular due to the standardization of specifications by the rared Data Association), and is equipped in notebook personal computers and portable information terminal devices. However, wireless communication using infrared rays is greatly affected by the distance between devices, the direction between devices, and external noise from fluorescent lights, etc.When a shield enters between devices during communication, communication continues until the shield is removed. Becomes impossible to continue. Therefore, due to these factors, the FCS (Fr
When an ame check sequence) error occurs and abnormal data is received, or when data is not received for a certain period of time, a retransmission request signal is generally transmitted to the transmission side.

[0003]

However, in the above-mentioned conventional example, particularly when communication is performed between the portable information terminal device having the infrared wireless communication means and another infrared wireless communication device, the portable information terminal is used. Since the device is held by hand and communicates toward the infrared wireless communication device on the receiving side, the distance between the devices may change during communication, or the direction may change and the infrared optical axis may shift slightly. . In such a case, there is a drawback that communication is not normally performed with the communication parameters once set, a communication impossible state occurs, and the communication must be restarted from the beginning. Further, since the receiving side device receives data continuously and at high speed, other processing may not be in time, and there is a possibility that the receiving buffer may be insufficient and the received data may be dropped.

The object of the present invention is to solve the above-mentioned problems,
Another object of the present invention is to provide an infrared wireless communication device that changes some or all of communication parameters during communication and continues communication.

[0005]

An infrared wireless communication device according to the present invention for achieving the above object is an infrared wireless communication device having an infrared light emitting means, an infrared light receiving means and an infrared wireless communication means. It is characterized in that the apparatus further comprises changing means for changing a part or all of the communication parameters after starting the communication according to the communication parameters set between the infrared wireless communication devices by agreement beforehand.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 is a block diagram of a block circuit of an infrared wireless communication device according to an embodiment, in which a control means 2 including a microcomputer for controlling each part of the infrared wireless communication device 1 is written with a program command and a reference table. ROM3, RAM4 for buffering received data and writing / reading as necessary, UART (Univers) for converting serial data / parallel data
al Asynchronous Receiver and Transmitter) 5, a clock oscillator (Band Rate Generator) 6 which supplies a clock signal for determining the communication speed, and a control means 2 which are respectively connected to a timer 7 which counts time as necessary, and outputs the clock oscillator Is connected to UART5.

The output of the UART 5 is an encoder 8 for encoding the format of the received signal from the UART 5, a driver 9,
It is sequentially connected to a light emitter 10 including an infrared LED emitting infrared rays. In addition, the output of the photodetector 11 which is, for example, a PIN photodiode or the like, which receives infrared rays from a partner device (not shown) and converts them into electric signals
2. A comparator 13 that outputs a high-level signal when the level is reached compared with a predetermined signal level, and a low-level signal when the level is not reached, a decoder that decodes the signal format 14 and UART5 are sequentially connected.

FIG. 2 shows a flowchart, and the operation of this embodiment will be described with reference to the flowchart. When mainly transmitting files, print data, or the like to a partner device (not shown), first, in the infrared wireless communication device 1 that is the primary station side during infrared wireless communication, the communication speed is set to a predetermined initial value, for example, in step S1. Set to 9600 bps. Thus, the control means 2 is set to output a clock signal of 16 times the communication speed, for example, 153.6 KHz, in order to communicate with the clock oscillator 6 at 9600 bps.

At this time, the other party infrared radio communication apparatus having a similar structure (not shown) has an initial value of the communication speed of 960.
It shall be set to 0 bps. After that, in step S2, a signal requesting a connection for data transmission is transmitted to the partner device, and the timer 7 is activated to start counting a predetermined time. When the response signal from the partner device is received in step S3, each communication parameter is negotiated in step S4.

At the time of transmission, if the control means 2 writes 1 byte of parallel data to be transmitted to the UART 5,
The parallel signal is converted into a serial signal in the UART 5, a start bit and a stop bit are added, and the signal is output to the encoder 8 in an asynchronous manner at a communication speed according to the clock signal from the clock oscillator 6. When the output is completed, the control means 2 is notified of the completion of the output, and the next data can be written.

The encoder 8 processes the serial signal received from the UART 5 according to a predetermined method, for example, as shown in FIG.
The signal format as shown in FIG. 3A is converted into the signal format as shown in FIG. Driver 9
Supplies a current to the light emitter 10 when the input signal is at a high level, and the light emitter 10 emits infrared rays.

On the other hand, at the time of reception, the photodetector 11 receives the infrared light transmitted from the other party's device, converts it into an electric signal, amplifies it by the amplifier 12, and then amplifies the signal amplified by the comparator 13 to a predetermined value. As compared with the signal level, a portion above a predetermined level is binarized to a high level, and a portion below a predetermined level is binarized to a low level and output to the decoder 14.

The decoder 14 converts the input signal from the encoded signal as shown in FIG. 3C, for example, as shown in FIG.
It is decoded into a signal as shown in and output to the UART 5.
When the UART 5 receives the serial signal from the decoder 14, the UART 5 notifies the control unit 2, deletes the start bit and the stop bit, converts the parallel signal into a parallel signal, and the control unit 2 reads and outputs the parallel signal.

According to the agreement in step S4, if the communication speed is set to 1 Mbps and the data size to be transmitted at one time is decided to be 1 Kbytes with the partner device, in step S5 the communication speed and Each communication parameter such as data size is changed / set, and in step S6, the clock oscillator 6 is set to output a 16 MHz clock signal for communication at 1 Mbps. On the other hand, if the response signal is not received from the partner device within the predetermined time in step S7, it is determined that the infrared wireless communication with the partner device is disabled for some reason. , The process ends.

The signal transmitted by the serial start-stop synchronization method with the start bit and the stop bit added forms a frame 20 as shown in FIG. One frame 2
The entire 0 is sent to the BOF unit 21 composed of a code for displaying the beginning of the frame 20, the address unit 22 for inputting the address code of the partner device, the control unit 23 composed of a code for the control information, and the partner device actually. It comprises a data section 24 for inputting data, an FCS section 25 for error control, and an EOF section 26 composed of a code for indicating the end of the frame 20. The data size at this time is the number of bytes of the data section 24. The frame 20 provided with the data section 24 is called a data frame, and the control frame 20 used as a connection request signal or response signal without the data section 24 is called a command frame. .

In step S8, transmission of desired data is started, and when the transmission is completed in step S9, a signal indicating the end of communication is transmitted to the partner device, and the process is completed. At this time, if communication is not completed in step S8, step 10
Then, in step S10, it is determined whether a communication error has occurred. If there is no communication error, the process returns to step S9. Step S10
If, for example, a response signal indicating reception has not been transmitted from the device on the other side even if it is retransmitted a predetermined number of times, the control means 2 sets the communication speed at this time to the initial value 9 in step S11.
The clock oscillator 6 is reset so as to return to 600 bps.

In this case, the partner device is not able to receive the data normally, or a communication error occurs such that the next signal is not received even if the response signal is transmitted.
Similarly, the communication speed of the partner device is also returned to the initial value of 9600 bps. After that, in step S12, a signal for making an agreement regarding the communication speed is transmitted again, and if there is a response from the partner device, the arrangement is made again, and the communication speed of both is determined to be the maximum possible communication speed under the current situation.

In step S13, it is judged whether or not the arrangement is completed, and if it is completed, the control means 2 is executed in step S14.
If the determined communication speed is 50 Kbps, for example, the clock oscillator 6 is set to output a clock signal of 800 KHz for communication at 50 Kbps, and communication is restarted in step S15. Also step
If it is judged in S13 that the arrangement is not completed, step
When it is determined in step S16 that the response signal is not received from the partner device within a certain period of time in step S16, infrared wireless communication with the partner device is not possible even if the communication speed is reduced. It is judged that there is some cause, and the processing is ended. If there is a response from the partner device in step S16, the process returns to step S13.

The pulse width (high level time) in FIG. 3 (b) is inversely proportional to the communication speed. When the communication speed is increased, the pulse width becomes shorter, and when the communication speed is decreased, the pulse width becomes longer. Therefore, the longer the pulse width of the infrared light emitted by the light emitter 10 is, the easier the light receiver of the partner device receives.

When the present invention is applied to a device whose main function is to receive data, such as a printer, even if the communication is started as described above and print data is received one after another, the printout process cannot be completed in time and is received. It is conceivable that the data buffer may overflow, or the received data may be dropped because the data could not be received.However, it is necessary to solve this problem by lowering the communication speed or resetting the data size. You can

Also, as one of the communication parameters, one of the parameters called the number of continuous data frames that can be continuously transmitted is set even if the command frame for confirming the reception of the data frame is not transmitted, and the transmitting side is set. If a buffer overflows or data is dropped while the receiving device is receiving data from
By changing the number of continuous data frames smaller than the number of continuous data frames set by the first agreement,
Communication can continue.

[0022]

As described above, in the infrared wireless communication device according to the present invention, the distance and direction between the communicating infrared communication devices change, and the communication continues with the communication parameters set by the first agreement. If it becomes impossible, the communication can be continued by resetting the communication parameter that enables communication again. If high-speed reception or continuous reception becomes difficult during data reception, data can be received by changing the communication parameters such as lowering the communication speed or reducing the data size and the number of continuous data frames. Can be

[Brief description of drawings]

FIG. 1 is a block diagram of a block circuit of an infrared communication device.

FIG. 2 is a flowchart.

FIG. 3 is a graph of a signal waveform.

FIG. 4 is a configuration diagram of a frame.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Infrared communication device 2 Control means 5 UART 6 Clock oscillator 8 Encoder 10 Light emitter 11 Light receiver 12 Comparator 13 Decoder 20 Frame 22 Address part 23 Control part 24 Data part 25 FCS part

Claims (1)

[Claims] 1. An infrared light emitting means, an infrared light receiving means,
In an infrared wireless communication device having a wireless communication means by infrared, after starting communication according to the communication parameters set between the infrared wireless communication devices by agreement beforehand, change means for changing a part or all of the communication parameters An infrared wireless communication device characterized by being provided.