Portable personal reception and display device for information tras itted via radio, combined with a watch
This invention relates to a portable personal reception and display device for information transmitted via radio, combined with a watch.
More specifically, the present invention relates to an integrated structure system comprising a radioreceiver to receive information transmitted via radio, associated with a processor and information display unit acting as a controller for the radioreceiver and operating in association with a watch, the assembly being powered by a self- contained electrical energy source associated with an optmized system for economizing energy consumption.
Even more specifically, the present invention relates to a system of the aforesaid type able to display information of various types transmitted via radio in accordance with the system currently known as RADIODATA, this being a supplementary service offered by radiotelephone networks and transmitted in a particular allocation within a transmission channel assigned to a certain radiotelephony transmitter.
For a better understanding of the present invention it is considered useful to briefly describe the type of radiotransmissions to which reference will be made in the preferred embodiment described herein- after.
In broadcasting systems it has been known for some time to more effectively use the radiofrequency channel width assigned to a transmitter by providing supplementary or complementary services without affecting the basic functions of the broadcasting system.
Examples of such more effective channel use are colour TV, so-called TELEVIDEO, and stereophony.
In the case of FM (frequency modulation) radiotransmissions in association with stereophony, it has been proposed to further exploit the FM radiofrequency channel to provide supplementary services transmitted within an auxiliary band which does not interfere either with monophonic transmission or with stereophonic transmission. Of the various proposed systems, reference will be made for the purposes of the present description to the RADIODATA (RDS) system, in the form of a suitably coded transmission as double side band - suppressed carrier modulation (DSB), with its carrier frequency centered on the third harmonic of the stereophonic transmission pilot signal usually centered on 19 kHz. Consequently, the rated frequency of the suppressed carrier is centered on 57 kHz. For further details of this transmission system reference should be made to the specialized publications well known to persons skilled in the art.
It is sufficient herein to state that RDS information is transmitted in code, in packets, with possible identification preamble and an error correction code end part, which information can contain data of various kind such as weather forecasts, road conditions, current news of particular importance, emergency information, etc.
The preamble to the information packet contains data relative to the type of information contained in the packet, for example identified as "weather forecast"; the end part contains a code composed as a certain algorithm with all the preamble information and informative content of the packet (such as an algorithm of the CRC or similar type), which can be reconstructed at the receiving end to determine whether what has been received is correct and to recognize and/or correct errors, and thus determine whether the received information packet is acceptable or must be discarded.
The main object of the present invention is to provide a portable personal reception and display device for information transmitted
according to the aforesaid briefly described techniques, combined with a watch, in particular a wrist-watch, which represents a complete self-contained system.
A further object of the present invention is to provide an economy optimization system for the electrical energy provided by a battery incorporated in the device in order to increase its self-sufficiency.
A currently preferred embodiment of the invention is described herein- after by way of non-limiting example with reference to the figures of the accompanying drawings in which:
Figure 1 schematically represents the spectral allocation of baseband frequencies of an information transmission system to which the device of the present invention is dedicated;
Figure 2 shows a possible time arrangement of the transmission of information of the kind processed by the device of the present invention;
Figure 3 shows the general schematic block diagram of the device of the present invention;
Figure 4 shows the detailed schematic block diagram of the radioreceiver and data decoding part of the device of the invention;
Figure 5 shows the detailed schematic block diagram of the device CPU;
Figure 6 shows the detailed schematic block diagram of auxiliary timing and control circuits of the device of the invention; and
Figures 7a and 7b are flow charts showing the operation of the device of the present invention.
The RADIODATA regulations and the transmission characteristics will be described briefly with reference to the drawings and in particular to Figure 1 and 2. ι
Specifically, Figure 1 shows the baseband allocation of the RADIODATA system. Important for the purposes of the present description are a pilot signal centered on 19 kHz indicated by Pc and the RADIODATA or RDS signal centered on a suppressed subcarrier at the third harmonic of the pilot signal at 19 kHz, i.e. 57 kHz. This RDS signal is transmitted in suppressed carrier double sideband (DSB).
Information transmission is substantially organized as shown in Figure 2. Information groups Gl, G2, G3, ..., each relating to a particular category of information, are transmitted with a periodicity for example of 1 hour or a submultiple.
Each of the groups Gl, G2, G3, ... is composed typically of three parts, namely preamble periods A, D, G, ... for identifying the information category; information periods B, E, H, ...; and periods C, F, I, ... containing a control code for verifying the correctness of the received information content in accordance with well known methods in the data processing field.
The device of the invention will now be described in general terms with reference to Figure 3.
The RADIODATA or equivalent signal transmitted for example in VHF in the 88-108 MHz band is picked up by an antenna 10 and fed to the input of a frequency modulation receiver 11. The signal demodulated and decoded by the receiver 11 is available at its output 12 and is fed to an input of a processor and general control unit indicated overall by 13. The processor and control unit 13 is associated with an assembly of manual controls 14 for feeding commands to said unit 13 via an interface 15
controlled by a strobe signal along a line 16. As will be seen herein¬ after, the purpose of the controls 14 is to select various functions made available by the unit 13. Said unit 13 is arranged to control via a group of lines 17 a first liquid crystal display unit 18 for displaying various options of a menu provided in the control program contained in the unit 13. This latter, via a group of lines 19, controls an alpha- numerical display, possibly with a graphic capacity, indicated overall by 20. In the case shown in Figure 3, the unit 20 is able to display for example eight alphanumerical characters.
The unit 13 frequency controlled by a quartz crystal XI drives a generator 21 for generating operating signals for a stepping motor which controls a watch movement 22 providing a watch function.
The unit 13 is powered by a battery 23, said unit 13 optimizing the energy drain by the device as described hereinafter. For this reason the VHF radioreceiver 11 is powered via a line 24 under the control of the unit 13.
Finally, the tuning of the receiver 11 is controlled by the unit 13 by signals fed along a line 25.
Figure 4 shows the detailed structure of the radioreceiver 11 of Figure 3 from the antenna to the exit point of the decoded signal present on line 11a.
With reference to Figure 4, the radiofrequency signal picked up by the antenna 10 is fed to a radiofrequency preamplifier 30, possibly after filtering through a wide-band radiofrequency filter, not shown, transparent to the frequency range of interest, which in the illustrated case is the 88-108 MHz band.
The signal from the radiofrequency amplifier 30 is fed to a conventional
frequency converter or mixer 31 in a well known manner related to superheterodyne radioreceivers. The output signal from the mixer 31 is filtered through an intermediate frequency .filter 32, for example centered on the rated intermediate frequency at 10.7 MHz, amplified through an amplifier/ limiter 33 and then fed to a frequency modulation demodulator indicated overall by 34. Many types of FM demodulators 34 and intermediate frequency filters 32 can be used, as is well known to a person skilled in the art.
The output signal from the demodulator 34, available along the line 35, has the spectral baseband structure shown in Figure 1.
A local oscillator signal is fed to said mixer 31. This is produced by an oscillator 36 the oscillation frequency of which is varied to effect tuning with variable reactance elements, such as a van"cap 37 driven by a digital/analog converter 38 controlled by a digital signal along a bus 39 associated with the control unit (13 in Figure 1). The digital/analog converter 38 can be one of the many types of DAC converters known in the literature.
In a preferred embodiment, the digital/analog converter 38 is of the PWM (Pulse Width Modulation) type in which a digital word applied to the bus 39 is converted into a pulse the duration of which varies according to the numerical value of the digital word, this pulse being converted into a direct voltage by a charge pump. Clearly, the digital word will have a sufficient number of bits to ensure adequate voltage resolution at the output of the DAC 38, and the rate of application of the digital word to the DAC 38 will be sufficiently high to ensure that the residual ripple in the control voltage applied to the varicap 37 will not create reception problems.
Finally, an AFC (Automatic Frequency Control) circuit can be incorporated via an output from the demodulator 34 which is connected in
known manner via a switch 40 to the local oscillator 36. The switch 40 is operated by the control unit 13 via a line 41 when a desired radiophonic transmitter has been tuned.
The baseband signal available along the line 35 is fed to a filter 42 which selects the RADIODATA signal centered on the frequency of 57 kHz (Figure 1). For reasons of overall size and of convenience of integrated circuit construction, the filter 42 centered on 57 kHz is preferably of the digital type controlled by digital signals provided along a bus 43 by the control unit 13.
The baseband signal along the line 35 comprising (Figure 1) a pilot signal at the frequency of 19 kHz is fed to a circuit 43 which extracts it and produces the third harmonic at 57 kHz (19 x 3 = 57). The third harmonic represents the reconstruction of the carrier of the RADIODATA signal which, as stated, is transmitted in double side band with suppressed carrier (DSB).
Said DSB signal from the filter 42 and the reconstructed carrier signal from the circuit 43 are fed to a demodulator 44 known in the art as a COSTAS demodulator, the structure of which is known from specialized literature (such as Arthur B. Williams, Designer's Handbook of Integrated Circuits, McGraw-Hill 1984).
The digital RADIODATA signal reconstructed by the COSTAS demodulator is fed to a serial to parallel output shift register indicated at 45, the parallel output of which is fed to a digital comparator 46 which receives a digital control word (Figure 2) from the control unit 13. In this manner, by suitable processing and timing, a signal is obtained at the output 47 of the comparator 46 which indicates to the central unit 13 that a RADIODATA message has been correctly received.
The structure of the CPU forming part of the central unit 13 will now be
described with reference to Figure 5. Figure 5 shows, a CPU 50 consisting of a dedicated microprocessor, for example a 8 bit processor. The CPU 50 is interfaced via a data/address bus 51 in known manner with a -ROM 52 containing the firmware, a RAM 53 divided as can be seen into two parts 54', 54", a first one arranged as a non volatile memory and the second as a conventional RAM; a first controller 55 for the display of messages (20, Figure 3), a second controller for the liquid crystal display (18, Figure 3) and an I/O unit indicated overall by 57.
The CPU is also interfaced with a bus 58 for controlling the digital/ analog converter for tuning the radioreceiver (39, Figure 4), a bus 59 for the RADIODATA signal filter (42, Figure 4), a bus 60 for the digital comparator for the control word (46, Figure 4), a bus 61 for a message data buffer 62 which receives the signals from the lines 11 and 46 of Figure 4, and finally a bidirectional bus 63 for a circuit indicated overall as a timer 64, the purpose of which is illustrated hereinafter.
The circuit part indicated overall as the timer in Figure 5 will now be described with reference to Figure 6.
The timer circuit comprises an oscillator 70 controlled by a quartz crystal XI to provide a time reference for a classical watch function and for other timings. The oscillator 70 is provided in known manner with compensators against shift due to temperature variations and with fine adjustment of oscillation frequency.
The output of the oscillator 70 is fed to a first digital divider 71 and then to a second digital divider 72 proportioned to provide pulses at a correct frequency to a control circuit 73 for a stepping motor operating a conventional watch mechanism indicated schematically by 74.
The counter 72 is provided with auxiliary inputs 75, 76, 77. The auxiliary input 75 is used under the control of a circuit 78 which
senses the state of charge of the general system powering battery 79, in order to increase (or decrease) the division ratio of the counter 72 if the battery 79 is semi-discharged, so as to warn the device user that the worn battery should be replaced.
The circuit 78 for sensing the battery charge operates in the following manner: when the battery voltage falls below a firs guard level, the circuit 78 regulates the control dividers for the stepping motor such that instead of activating one step every second, they activate three steps every three seconds and then, at a second guard level, six steps every six seconds and so on. By proceeding in this manner a considerable reduction is obtained in the battery energy consumption.
When the circuit 78 operates there is therefore a less gradual or more "jumpy" movement of the minute hand.
The inputs 76, 77 cause fast advancement of the hour and minute hands of the watch mechanism 74 under the command of the control unit 80 following operation of pushbuttons of the unit 14 which are associated with an interface 15. The pushbuttons control, for example, Hall effect sensors suitably connected to the unit 80 by means of a bus 81. The interface 15 is strobed with a command 16 for example at the rate of one pulse every three seconds, provided by a divider 82 controlled by the oscillator 70.
The oscillator 70 is also connected to a divider 83 for providing pulses spaced apart by 60 minutes along a line 84 to periodically activate the system. An output 85 with a repetition rate of one second is fed from the divider 82 to a further counter 86 controlled by a line 88 from the unit 80 to provide repetition pulses every 20 seconds along the line 87.
The electrical energy provided by the battery 79 is delivered, under the control of an electronic switch 89 operated by the line 90, only at
determined times to the radioreceiver and to the associated circuitry in order to minimize electricity consumtpion and thus increase the life of the battery 79.
The operation of the device according to the present invention will now be described with reference to the flow chart of Figures 7a and 7b.
It will be assumed that the device has just been switched on or that the command fed along the line 84 of Figure 6 every 60 minutes has produced the START state (block 100).
From block 100 the control passes to the "RESET to 60 min" block 101 which feeds a command 102 to the power control unit (line 90 of Figure 6) which also feeds electrical energy from the battery 79 to the radio- receiver, to the CPU 50, to the display unit, etc.
The program comes together again at the point 103, from which the CPU 50 initiates the tuning sweep of the radioreceiver 11 of Figure 1 by feeding digital words along the bus 39 connected to the DAC converter 38 which controls the tuning elements 37. The operation of the receiver does not require detailed explanation as it is of well known structure.
Tuning is therefore controlled by the block 104 until the comparator 46 of Figure 4 generates a signal along the line 47 corresponding to the decision block 105. If a correct word is not received the tuning control 104 searches for a further transmitting station unitl a correct identification word signal is obtained along the line 47, corresponding to an affirmative decision of the block 105.
At this point the RDS data, corresponding for example to the group defined as "5A", is decoded in the block 106 and the messaage data are written into the RAM 53 of Figure 5 (block 107).
If the decision block 108 finds that the data are not yet finished the writing operation proceeds along the loop 109. If the data are finished, the control -passes to the block 110 which controls the power on to the device CPU.
Control then passes to the menu selection block 111 (using the controls 14, 15 of Figures 3 and 6), which activates (via 112) the menu display 113. The decision block 114 now acts for any required menu change. The subsequent blocks 115, 116, 117, 118 and 119 of the flow chart of Figure 7b check the timings and the correctness of the data received. The block
119 decides whether correct data have not been received for instance for a time t = 10 seconds. In such a case, the control passes to the block
120 which turns off the display. If however correct data have been received control passes from the block 119 to the block 121 for display of RADIODATA messages.
The aforegoing description based on the flow chart of Figures 7a and 7b is given by way of non-limiting example.
It should also be noted that the firmware of the data processing system can be varied in terms of particular circuit and/or component arrangements based on the choices made during the design of the device according to the invention.
In addition, with regard to the radioreceiver, various different types of reception/demodulation arrangements are possible for the radio signals carrying the required information. In the limit, single-chip radioreceivers can be used, of which only the external characteristics are known, whatever their effective internal structure is.
Equally, with regard to the calculation, data processing and data display circuits, numerous arrangements currently available in the state of the art for the integration of complex functions are conceivable.
In addition, the RADIODATA system given as the example is also to be considered only indicative and non-limiting, in that a person skilled in the art can easily conceive other transmission systems either of dedicated type or integrated as auxiliary transmissions on standard transmissions with or without an auxiliary subcarrier.
Finally, the present invention has been described with reference to a currently preferred embodiment given by way of non-limiting example only, and modifications can be made thereto in practice by a person skilled in the art but without leaving the field of protection of the present patent.