WO1992022048A1

WO1992022048A1 - Method of transmitting signals in an ir remote-control system

Info

Publication number: WO1992022048A1
Application number: PCT/CH1992/000100
Authority: WO
Inventors: Markus Thaler; Urs Jost; Stefan Sigrist; Peter Schmid
Original assignee: Feller Ag
Priority date: 1991-05-30
Filing date: 1992-05-27
Publication date: 1992-12-10
Also published as: FI930356A; PT100553A; NO307677B1; FI111668B; EP0552323A1; EP0552323B1; NO930329L; ES2137184T3; ATE184411T1; FI930356A0; DE59209743D1; CA2088046A1; NO930329D0; JPH06500450A

Abstract

To transmit, from a transmitter to a receiver, signals triggered by prolonged depression of a button, the invention calls for repeat signals (R) to be transmitted while the button is kept depressed. Releasing the button triggers a separate switch signal (S). A burst/pause modulation technique is used to transmit the repeat and switch signals (R and S), the information units being defined by different burst-separation lengths. The burst separations and burst packets are chosen such that IR transmitters with only limited power supplies can be used.

Description

Transmission method for an infrared remote control system

TECHNICAL AREA

The present invention relates to a transmission method for an infrared remote control system for transmitting data sequences or telegrams, triggered by long and short keystrokes on a keyboard, between a transmitter and a receiver, where the different key presses of the keyboard are interpreted.

STATE OF THE ART

Pseudo-continuous processes, for example the sequential running through a series of discrete control values, are conventionally carried out during a keystroke, for example in the case of remote control by transmitting one command per step, or by transmitting a few commands, the non-arrival of a command during a certain time as the end of the Keypress is interpreted, or controlled by the transmission of the beginning and end of the keypress

For the transmission of binary coded data groups resp. Data sequences, i.e. So-called transmission protocols are used for data which are represented by on or off states. A station transmits such data sequences, for example with the aid of high-frequency waves, and a receiving station evaluates the received data sequences, for which purpose it must know the transmission protocol. This essentially determines the form and content of the transmitted data and only makes it evaluable.

A large number of such protocols are known and are used in the entire data transmission technology. The large number of different protocols is mainly explained by the variety of uses, such as data transmission of computer information or purely control information. for apparatus. In particular, data security, integrity and transmission speed are decisive influencing factors, some of which interfere with each other. The transmission medium must also be taken into account.

The object of the invention is to find a transmission method that ensures the safe transmission of a long key press with the smallest possible number of commands, the end of the key press should be recognized as accurately as possible, and which only requires a limited amount of energy

SUMMARY OF THE INVENTION

This object is achieved according to the invention in that repeat signals R are transmitted repeatedly by the transmitter from pressing until the key on the keyboard is released, the release of the key generating a separate changeover signal S and ending the transmission of the repeat signals R, and for transmission the repetition and changeover signals R and S a burst-pause modulation method is provided in the transmitter, the number of burst periods per burst packet of duration TB, and the burst intervals TAO, TA1 ... being chosen in such a way that during the pauses with a power supply low voltage and capacity to charge a memory via a DC / DC converter, which provides the necessary energy and voltage amplitude for the transmission

A preferred embodiment of the invention is characterized in that a circuit is provided which, in the receiving device, does not interpret the lack of a repeat command as the end of the key press but only as an interruption

A further, preferred embodiment of the invention is characterized in that the first repeat signal is emitted after a longer pressing of the key than 400 milliseconds and is repeated at intervals of at most 1 second until the key is released. A special, preferred embodiment of the invention is characterized in that a circuit is provided in the receiver, which after receiving a

Repeat signals during at least the interval of the repeat signals one

Number of discrete control signals generated

By means of the transmission method according to the invention, pseudo-continuous processes can be reliably controlled with the aid of a long button press on the transmitting device, for example of several seconds. If the repetition signal is interrupted, the process is not interrupted, but merely interrupted, and can be continued when the repetition signals are received again. As a result, for example in the case of a light control device, a dimming process which is initiated and continued by means of a long push of a button is not interrupted because of the interruption of the transmission signal, for example by temporarily covering the transmitter-receiver connection, but merely interrupted. As soon as further repetition signals are received, the dimming process is continued in the original direction. When the button is released, a changeover signal is sent, for example, as a separate command for a light control. This changeover signal indicates the end of the current process, for example the dimming process described. In this way, for example, the direction of the dimming function can be reversed and the next repeat signals received cause a dimming effect opposite to the original direction. The preferred embodiments of the invention provide that 16 periods are used per burst packet, and the interval between breaks is at least 10 times the burst packet length

Another preferred embodiment provides that four different information units with four different burst distances are used, with one information unit each for identifying the start or. the end of the data sequence and to represent states 0 and 1.

The method according to the invention makes it possible to reliably transmit telegrams or data sequences even with transmitters with a weak energy supply. It is now possible for the transmitter to refresh its energy store during the burst intervals in order to send out the next burst packet with sufficient power. The energy store no longer has to be dimensioned so large to ensure uninterrupted transmission power. Smaller-sized energy stores are also noticeably smaller in terms of dimensions and weight than larger energy stores, which means reduced dimensions and smaller weight, and thus greater ease of use, especially for hand transmitters

DESCRIPTION OF THE INVENTION

An exemplary embodiment of the invention is explained in more detail below with reference to drawings

Show it :

Figure 1 is a block diagram of the transmitter according to the invention

Figure 2 The entire address range of the transmitter

Figure 3 The telegram structure of a telegram to be transmitted

Figure 4 The circuit diagram of the transmitter power

Figure 5.6 The PPM coding and the modulated PPM signal of the transmitter

Figure 7 is a block diagram of the receiver according to the invention

Figure 8 is a block diagram of the preamplifier

Figure 9 A diagram of the signal transmission depending on a long T.

Pushing a button and the corresponding light control Figure 10 A diagram of the signal transmission depending on a short

Key press, and the corresponding ON / OFF control.

WAYS OF CARRYING OUT THE INVENTION

FIG. 1 shows the block diagram of the transmitter 10. The transmitter 10 is, for example, an infrared transmitter for controlling various electrical consumers, such as lighting fixtures, audio devices and window blinds. The transmitter 10 consists of a keyboard 12, a first microprocessor or ASIC 14, a feed 16, an address preselector 18 and a transmission stage 20.

When any key on the keyboard 12 is pressed, the feed 16 is activated via a first control signal S1 of the keyboard 12 and builds it for the microprocessor or ASIC 14 and the supply voltage VS necessary for driving the transmission diode D2 of the transmission stage 20. As soon as the supply 16 has reached the necessary voltage, the microprocessor or ASIC 14 starts up and takes control of the supply 16 with a second control signal S2. The output signal T5 of the keyboard 12 is read in by the microprocessor or ASIC 14 and indicates which key on the keyboard 12 was pressed.

The first control signal S1 and the second control signal S2 are assigned to a logic OR circuit 19 which generates a third control signal S3 which activates the supply 16

The microprocessor or ASIC 14 then generates a fourth address control signal S4 with which the device address AI, A2, A3, A4 .... set on the address selection device 18 with the aid of coding switches 22 is selected by a logic circuit 21.

The addresses are represented, for example, with eight address bits, the address space (see FIG. 2) being logically divided into four banks (2 bits), each with eight groups (3 bits), each with eight device addresses (3 bits)

A group address G can be set on the transmitter 10 using a coding switch 22, and four device addresses can be freely selected within this group. The bank address is hardwired.

The command transmission between the transmitter 10 and the receiver of a control device is based on individual data sequences or telegrams (one * command is transmitted per telegram), the information being digitally encoded.

The telegram structure of a telegram is shown in Fig. 3. A telegram consists of:

- eight address bits

- four data bits

- four data backup bits (CRC coding)

- a start bit SOT (Start of Telegram)

- a stop bit EOT (End of Telegram) The start bit SOT and the stop bit EOT are used for synchronization purposes so that the start or end of a telegram is clearly recognized.

Exactly one of these device addresses is assigned to each key of the keyboard 12. The device address specified in the output signal A5 of the logic circuit 21 determines the three least significant bits of the address field in the telegram (FIG. 3). At the same time, the group address G set with the coding switch 22 is read in and determines the three higher-order address bits of the telegram. The two most significant bits of the address field are filled with corresponding bank addresses. Depending on the length of the keystroke on the keyboard 12, the four data bits are used to represent the corresponding commands. The address and data field generated in this way is supplemented with the further bits for data backup (CRC Coding) and so the telegram (Fig. 3) is formed

The microprocessor 14 carries out a burst-pause modulation (pulse position modulation and subsequent carrier frequency modulation) and generates a transmit control signal TM for actuating a transmit amplifier 24 which is connected in series with the transmit diode D2

This transmit amplifier 24 generates the transmit current IS through the diode D2, which generates light signals in the infrared range in accordance with the current. Since the supply cannot provide enough energy to generate the transmit current IS, a capacitor C1 is used for intermediate storage of the energy, which is dimensioned in this way that an entire telegram with at least the current strength IS can be sent.

As soon as no further telegrams have to be sent due to the key being pressed (key released), the microprocessor or ASIC 14 deactivates the supply 16 by means of the second control signal S2, with which the current consumption in standby mode can be reduced to a negligible value.

The circuit of the feed 16 is shown in FIG. 4 Only one battery 26 with a low voltage (1.5 volt cell) is used to supply the transmitter 10. However, a higher voltage is required to control the infrared transmitter diode D2 and the microprocessor or ASIC 14. This is achieved by the battery 26 A magnetic DC / DC converter 28 is connected in series, which transforms the low input voltage VB to a higher voltage level VS. A control circuit 32 is activated via the control input 30 of the third feed control signal S3, thus switching a transistor T1 and on Current IL begins to flow through a coil L. A quantity of energy proportional to the current is stored in the coil L. If the transistor T1 is now switched off, the energy in the coil dissipates and flows through a diode D4 into the capacitor C1, which causes a voltage to build up across the capacitor C1 repeated switching on and off of the transistor T1, energy packets are transmitted into the capacitor C1, which gradually builds up the voltage. This continues until the desired voltage VS is built up across the capacitor C1. The control circuit 32 determines that the desired voltage has been reached and detects it switching the transistor T1 on and off periodically until the control voltage UR drops below a predetermined value. The periodic switching on and off is generated by an oscillator, and the coil L can also be used as a frequency-determining component. The oscillator is built in the control circuit 32

When the infrared transmitter 10 is activated, the voltage converter 28 is put into operation. The voltage of the battery 26 is thus transformed to the desired, higher voltage level VS and is preferably stored in the capacitor C1 as an energy supply. After a defined period of time, the telegram to be transmitted is transmitted by means of of the controlled transmit amplifier 24 and the infrared diode D2 and the capacitor C1 is thus partially emptied again. This makes it possible, for example, to get by with a single 1.5 volt cell as the energy source. The IR transmitter 10 can thus be made smaller than conventional, or have more space for the transmitter electronics. Fewer batteries also need to be replaced.

The telegram transmission method is shown schematically in FIGS. 5, 6

Only a limited power supply is available in transmitter 10 (battery, 1.5 V, type AAA), which is why the transmission method must be selected in this way that the required range (approx. 20 m) and the service life (approx. 3 years under normal conditions of use) for the battery 26 can be maintained.

The telegram is transmitted using a burst pause modulation method. For this transmission, the individual bits are encoded in the microprocessor 14 using a PPM method (pulse position modulation) and then modulated with a carrier frequency. The information carrier in this encoding is the distance between two pulses (TAO, TA1 FIG. 5).

A total of four different distances are used: EOT, "O", "1" and SOT. Since the unmodulated PPM process is broadband, the individual pulses are modulated with a carrier frequency (447.5 KHz) in such a way that 16 periods of the carrier frequency are transmitted per pulse. Such a pulse packet is referred to as a burst with the burst length TB (32 us). The modulated PPM signal (FIG. 6) is referred to as a BPM signal (burst position modulation). This coding and modulation method is very energy-saving since energy is only consumed during the burst phases and the distances between the bursts (TAO, TB, TA1-TB, etc.) can be used to at least partially fill up a temporary energy store, especially if the burst distances are chosen much larger than the burst length.

Stop bit EOT 14 * TB bit O 19 * TB bit l 24 * TB start bit SOT 29 * TB

A burst packet of duration TB has, for example, 16 periods, ie 16 short light flashes are emitted by the IR transmitter diode D2. After a distance of the duration TAO, a second burst packet is emitted again. The burst intervals TAO, TA1 are chosen so that the transmitter 10 has enough Time remains, namely TAO - TB, in order to prepare the still missing energy for the transmission of the following burst packet if it does not always have a sufficient energy reserve. This means that transmitters with a weak energy source can transmit Such infrared signals can be used in that they do not continuously emit a weak signal, but only emit a stronger signal, the burst, for a limited period of time. In particular, the dimensions and the weight of the transmitting device can thus be reduced, since the energy source, in particular in hand-held transmitters, is usually the heaviest and most inflexible element in terms of dimensions

The receiver 36 (FIG. 7) thus evaluates the burst distances between the received burst packets, recognizes the various telegrams, and forwards them to an evaluation circuit 38 in accordance with the above coding.

The receiver 36 consists of a receiving diode Dl which converts infrared signals into current, a preamplifier 40 which pre-processes the received weak current signals in such a way that they can be further processed by a downstream second microprocessor 42 of the evaluation circuit 38.

In the receiver 36, the infrared light signal (light burst packet) is converted into a current burst with the receiving diode D1. A bandpass 44 (FIG. 8) can be used to filter this current burst, which sufficiently dampens all disturbances that are not in the range of the carrier frequency is capable of allowing the bursts to pass Most interference frequencies in the infrared range are in the frequency range around 40 kHz (e.g. ballasts etc.)

The preamplifier 40 (FIG. 8) is designed in such a way that the received signals are first filtered and then amplified. After the amplification, the number of periods of the received signal is counted in a pulse counter 46 and if the required number of periods has been received, a single receive pulse S5 is forwarded to the second microprocessor or ASIC 42, which then evaluates the intervals between these pulses

The evaluation circuit 38 of the receiver 36 also contains two coding switches 48 for determining the device address AI (3 least significant bits) and the group address G (3 more significant bits). The second microprocessor 42 reads these addresses when a command telegram is received and compares the address field with the address set on the receiver 36. If the addresses match, the command is saved for further processing, otherwise it is discarded. At the same time the command telegram is checked for incorrect transmission with the aid of the data backup bits. If the received telegram is found to be not in order, the telegram is rejected.

The evaluation circuit 38 further contains a memory 50 (RAM / EEPROM) for storing states for the control of the control unit 52. The so-called MODE inputs inform the microprocessor 42 which type is to be controlled by the control unit 52, with which it then does the corresponding Retrieves the program in the program memory 54 (ROM). It is thus possible to use a single microprocessor 42 to generate a number of different control signals S6 for different types of control units 52 (for example phase control, relays, etc.), depending on the MODE inputs.

FIG. 9 shows a diagram of the transmitter transmission from a long button press with infrared transmission of the telegrams using a restricted energy supply in the transmitter for controlling continuous and pseudo-continuous processes with only one button.

A key (for example T1) on the keyboard 12 of the transmitter 10 is pressed at the time TD and released at the later time TE, as shown in FIG. 9 in the upper diagram

If the keystroke lasts longer than TW (TW is 400 ms), the keystroke is interpreted as "long", and from this point on repeat signals R (or HOLD commands) are sent at a distance TR from the first (microprocessor 42) until the key is released at time TE. In this connection, a switchover signal S (or TOGGLE command) is sent by the microprocessor 42, and the transmission of the repeat signals R ends. At the same time, the release of the key causes a reversal of direction for the control variable. A long key press can be used, for example, to control a pseudo-continuous process so that the output control signal S7 of the control unit 52 of the receiver 36 is changed by a small amount delta S in small time steps delta T, e.g. dimming lights.

Because of the limited energy supply (battery) in the transmitter 10, the distance TR of the repetition signals must be chosen to be sufficiently large (little energy consumption). consumption and thus increased battery life), on the other hand, the end of the key press should be able to be detected as precisely as possible by the receiver 36, for example to be able to set the end value as precisely as possible when dimming. For this purpose, the switchover signal S is sent when the key is released and the receiver 36 interprets this as the end of the key press. The distance TR between the repeat commands can thus be chosen to be large (800 ms). The time steps delta T for the control variable are small in relation to the distance between the repeat commands R (approx. 60 ms) and the end value can still be set precisely because the switch signal is sent immediately when the button is released.

An error in the transmission of the repeat signal R is not interpreted in the receiver 36 as the end of the keystroke, which would also result in a change of direction, but rather as an interruption, the time period TT until the interruption being detected being greater than the time period of the interval TR of the repeat commands R is selected (TT: ls). If such an interruption is detected at the time TU, the control signal S7 is no longer changed until a repeat signal R is received again, in this case no change in direction is noted. The absence of the final changeover signal S is interpreted as an interruption, i.e. a subsequent long button press on the transmitter 10 is interpreted in the receiver 36 as a resumption of the original button press

Fig. 10 shows the diagram of the transmitter transmission for a short button press that lasts less than 400 ms. A changeover signal S is sent by the microprocessor or ASIC 14, which switches the receiver 36 to ON or. OFF switches depending on whether the current state is OFF or. Was one.

The HOLD function is used to establish a logical connection between transmitter 10 and receiver 36 and is used to transmit a long key press (> 400 ms).

A short key press generates a switchover signal S or switchover telegram, a long key press generates repeat signals R or repeat telegrams, followed by a switchover telegram S when the key is released.

Claims

PATENT CLAIMS

1. Transmission method for an infrared remote control system for transmitting data sequences or telegrams, triggered by long and short key actuations of a keyboard (12) between a transmitter (10) and a receiver (36) where the different key presses of the keyboard (12 ) are interpreted, characterized in that repetitive signals (R) are repeatedly transmitted from the transmitter (10) from pressing to releasing a key of the keyboard (12), the releasing of the key generating a separate changeover signal (S) and the transmission of the repetition signals (R) is ended, and a burst pause modulation method is provided in the transmitter (10) for the transmission of the repetition and changeover signals (R) and (S), the number of burst periods per burst packet being the duration TB, and the burst distances TAO, TAl ... are chosen to convert during these pauses despite a power supply (26) with low voltage and capacity via a DC / DC r (28) charge a memory which provides the necessary energy and voltage amplitude for the transmission

2. Transfer method according to claim 1, characterized in that a circuit is provided which, in the receiver (36), lacks a Repetier¬ signal (R), which repeats after a longer press than 400 milliseconds and at intervals of at most 1 second until Release of the key is sent, not interpreted as the end of the key press but as an interruption

3. Transmission method according to claim 1, characterized in that 16 periods are used per burst packet, four different information units with four different burst spacings being required in order to each have an information unit for identifying the start or. the end of the data sequence and the representation of states 0 and 1 and that the burst spacing is at least 10 times the burst packet length

4. Transmission method according to claim 1, characterized in that the voltage converter necessary for the generation of the transmission energy is a magnetic converter, which is followed by a capacitor (Cl) for the intermediate storage of the energy

5. Transmission method according to claim 1, characterized in that the

Receiver (36) generates a number of discrete control signals (S7) after receiving a repeat signal (R) during at least the interval between the repeat signals

6. Data transmission device between an infrared transmitter (10) and an infrared receiver (36), in which the transmitter (10) contains a keyboard (12) with an address selection circuit (18) and at least one transmitter diode (D2) characterized in that a microprocessor or ASIC (14) is provided in the transmitter (10), which carries out PPM coding and a subsequent carrier frequency modulation in order to generate a transmission control signal (TM) that is used to control a transmission amplifier (24) which is connected in series with at least one transmitter diode (D2) is required, and that the microprocessor or ASIC (14) deactivates the supply (16) of the transmitter (10) when the button is released.

7. Data transmission device according to claim 6, characterized in that the receiver (36) contains at least one receiving diode (Dl) which is controlled by a microprocessor or ASIC (42) so that the received pulses or burst packets of the receiving diode (Dl) are filtered and shaped in a preamplifier (40) and that the microprocessor or ASIC (42) evaluates the distances between the pulses in order to recognize the different telegrams.