US 6,957,133 B1
`
`1
`SMALL-SCALE, INTEGRATED VEHICLE
`TELEMATICS DEVICE
`
`BACKGROUND
`
`1. Field
`
`Embodiments of the present invention relate generally to
`vehicle telematics. More specifically, embodiments relate to
`wireless, internet-based systems that collect, transmit, and
`analyze diagnostic and location—based data from a motor
`vehicle.
`
`2. Description of Related Art
`Some vehicles include global positioning systems
`(‘GPSs’). A conventional GPS features an antenna that
`receives signals from orbiting satellites and a chipset that
`processes these signals to calculate a GPS ‘fix’. The fix
`features data such as a vehicle’s latitude, longitude, altitude,
`heading, and velocity. The fix describes the vehicle’s loca-
`tion with a typical accuracy of about 10 meters or better.
`Light—duty automobiles and trucks beginning with model
`year 1996 include on-board diagnostic (OBD-II) systems as
`mandated by the Environmental Protection Agency (EPA).
`OBD-II systems monitor the vehicle’s electrical,
`mechanical, and emissions systems and generate data that
`are processed by a vehicle’s engine control unit (ECU) to
`detect malfunctions or deterioration in the vehicle’s perfor-
`mance. The data typically include parameters such as
`vehicle speed (VSS), engine speed (RPM), engine load
`(LOAD), and mass air flow
`The ECU can also
`generate diagnostic trouble codes (DTCs), which are 5-digit
`codes (e.g., ‘P0001’) indicating electrical/mechanical prob-
`lems with the vehicle. Most vehicles manufactured after
`1996 include a standardized, serial 16-cavity connector,
`referred to herein as an ‘OBD-II connector’, that makes
`these data available. The OBD-II connector serially com-
`municates with the vehicle’s ECU and typically lies under-
`neath the vehicle’s dashboard.
`
`Conventional GPSs can be combined with systems for
`collecting the vehicle’s OBD-II diagnostic data to form
`‘telematics’ systems. Such telematics systems typically
`include (1) a microprocessor that runs firmware that controls
`separate circuits that communicate with different vehicle
`makes (e.g., Ford, GM, Toyota) to collect OBD-II data; (2)
`a GPS module; and (3) a separate wireless transmitter
`module that transmits the GPS and OBD-II data.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1A is a schematic drawing of a wireless appliance
`according to an embodiment of the present invention.
`FIG. 1B is a schematic drawing of a wireless appliance
`according to an embodiment of the present invention fea-
`turing an integrated antennae and custom ASICs for power
`management, OBD-II communication, GPS, and a wireless
`transmitter.
`
`FIG. 2 is a schematic drawing of a vehicle featuring a
`wireless appliance that communicates with a GPS, a wire-
`less communication network, and an Internet-accessible web
`page according to an embodiment of the present invention.
`FIG. 3 is a screen capture of a web page that displays a
`vehicle’s diagnostic data monitored by the wireless appli-
`ance of FIG. 1B according to an embodiment of the present
`invention.
`
`FIGS. 4A and 4B are web pages displaying, respectively,
`screen captures of a vehicle’s numerical latitude and longi-
`tude and a map showing the vehicle’s location monitored by
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`the wireless appliance of FIG. 1B according to an embodi-
`ment of the present invention.
`FIG. 5 is a schematic drawing of an ASIC used for the
`vehicle-communication circuit of FIG. 1B according to an
`embodiment of the present invention.
`FIG. 6 is a logic diagram for the J1850 VPWM and J1850
`PWM circuits used in the ASIC of FIG. 5 according to an
`embodiment of the present invention.
`FIG. 7 is a logic diagram for the ISO 9141-2 circuit used
`in the ASIC of FIG. 5 according to an embodiment of the
`present invention.
`DETAILED DESCRIPTION
`
`The following description refers to the accompanying
`drawings that illustrate certain embodiments of the present
`invention. Other embodiments are possible and modifica-
`tions may be made to the embodiments without departing
`from the spirit and scope of the invention. Therefore, the
`following detailed description is not meant
`to limit
`the
`present invention. Rather, the scope of the present invention
`is defined by the appended claims.
`Embodiments of the present invention provide a small-
`scale, wireless, internet-based system for monitoring and
`analyzing a vehicle’s GPS and diagnostic data. Specifically,
`embodiments provide a system that supports the above-
`mentioned functions using a wireless appliance based on an
`integrated, silicon-based architecture. The architecture fea-
`tures an application—specific integrated circuit (‘ASIC’) for
`communicating with multiple types of OBD-II systems. It
`also includes a GPS system and wireless transmitter that use
`antennae that are integrated into the wireless appliance. This
`results in a small, compact device that can be easily installed
`in a vehicle in a matter of minutes.
`
`The wireless appliance monitors location and diagnostic
`data to provide services such as roadside assistance to a
`disabled vehicle or recovery of a stolen vehicle. In a related
`implementation, the appliance provides a GPS-based system
`for alerting a vehicle’s owner that someone other than the
`owner has moved the vehicle (e.g., the vehicle is stolen or
`towed).
`More specifically, in one aspect, the invention provides a
`wireless appliance for monitoring a Vehicle that includes: (1)
`a microprocessor, (2) a vehicle-communication circuit; (3) a
`GPS module; and (4) a wireless transmitter. The wireless
`transmitter receives and transmits location—based data gen-
`erated by the GPS module and diagnostic data collected by
`the vehicle-communication circuit. The vehicle-
`communication circuit is integrated into a single ASIC that
`includes modules for managing dillerent vehicle-
`communication protocols, e.g. ]1850 PWVI (a protocol for
`Ford Vehicle), J1850 VPWM (General Motors), ISO 9141-2
`(Toyota and other Japanese makes), CAN (e.g. ISO—15765;
`a next-generation protocol), Keyword 2000 (Hyundai,
`Mercedes), and J1708 (for medium and heavy—duty trucks,
`such as trucks made by Volvo, Kenworth, CAT, Hino). Each
`protocol is described in more detail below.
`In one embodiment,
`the wireless appliance includes a
`multiplexing circuit that provides electrical communication
`between the microprocessor and one of the modules. The
`multiplexing circuit, for example, can switch electrical com-
`munication from one module to another.
`In other
`embodiments, the vehicle-communication circuit includes a
`microcontroller that connects to the microprocessor using an
`asynchronous serial connection.
`The microprocessor may run firmware that determines the
`vehicle-communication protocol of a host vehicle. Once this
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`US 6,957,133 B1
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`3
`is determined, the microprocessor selects the appropriate
`module in the vehicle-communication circuit that supports
`the vehicle-communication protocol.
`In other embodiments, the wireless appliance includes a
`GPS antenna in electrical contact with the GPS module; a
`radio antenna in electrical contact with the wireless trans-
`mitter; and a single housing that houses the GPS antenna, the
`radio antenna, and all the other components in the wireless
`appliance.
`The wireless appliance can also include an internal bat-
`tery. In this embodiment, the appliance receives power from
`the vehicle’s standard 12-volt battery and uses the internal
`battery as a ‘back up’ power supply in case this power is
`interrupted. In another embodiment, the appliance includes
`a single chipset that includes both the GPS module and the
`wireless transmitter.
`
`In another aspect of the invention, the wireless appliance
`features a substrate (e.g., a printed circuit board) that sup-
`ports the microprocessor,
`the vehicle-communication
`circuit, a GPS module and its antenna, and the wireless
`transmitter and its antenna.
`
`In another aspect of the invention, the wireless appliance
`features a microprocessor that controls and processes data
`from both the vehicle-communication circuit and the GPS
`module. In this case, the GPS module receives GPS signals
`from an antenna and generates data in response. The GPS
`module then sends the data to the microprocessor to calcu-
`late location—based data. In this embodiment, both the GPS
`and radio antennae may be housed with the wireless appli-
`ance in a single enclosure. In other embodiments, a single
`chipset or ASIC includes both the GPS module and the
`wireless transmitter.
`
`In another embodiment, the wireless appliance features a
`mechanical adaptor based on a connector that powers and
`provides a data link (e.g. a serial connection) to a plurality
`of wireless transmitters that each operate on different wire-
`less networks. For example, the mechanical adaptor powers
`and provides a data link to wireless transmitters operating on
`terrestrial wireless networks such as CDMA, GSM, GPRS,
`AMPS, Mobitex, and DataTac, and satellite networks such
`as ORBCOMM. In this embodiment, the wireless appliance
`only hosts a single wireless transmitter at any time; this
`transmitter can then be replaced with a different device,
`operating on a different network, at a later time. The
`microprocessor is configured to determine the wireless net-
`work associated with the transmitter, and then direct a
`power-conditioning circuit to supply the correct power to the
`mechanical adaptor.
`In another aspect, the invention provides a single ASIC
`that features (1)
`a microprocessor;
`(2) a vehicle-
`communication circuit containing multiple vehicle-
`communication modules;
`(3) a GPS module; and (4) a
`wireless transmitter. In embodiments, the ASIC additionally
`includes a multiplexing circuit configured to switch electri-
`cal communication from one vehicle-communication mod-
`ule to another.
`
`In other embodiments of the present invention, a moni-
`torable vehicle is provided. The vehicle may include, for
`example, an engine, transmission, braking mechanism, elec-
`trical system, on-board diagnostic system, and wireless
`appliance. The on-board diagnostic system is configured to
`query data relating to the vehicle, for example, related to the
`engine, transmission, braking mechanism, and/or electrical
`system.
`In some embodiments,
`the wireless appliance
`includes a substrate, a microprocessor supported by the
`substrate, a vehicle-communication circuit, a GPS module,
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`and a wireless transmitter. The vehicle-communication cir-
`cuit is in electrical communication with the microprocessor,
`includes modules that each manage a vehicle-
`communication protocol, and is interfaced with the on-board
`diagnostic system. The GPS module is in electrical commu-
`nication with the microprocessor and includes a GPS
`antenna connected to the substrate. The wireless transmitter
`is configured to receive and transmit data generated by the
`GPS module and collected by the vehicle-communication
`circuit, and includes a radio antenna connected to the
`substrate.
`In particular,
`The invention has many advantages.
`wireless, real-time transmission and analysis of GPS and
`diagnostic data, followed by analysis and display of these
`data using an Intemet-hosted web site, makes it possible to
`characterize the vehicle’s performance and determine its
`location in real-time from virtually any location that has
`Internet access, provided that
`the vehicle being tested
`includes the below-described wireless appliance. These data
`are complementary and, when analyzed together, can
`improve conventional services such as roadside assistance,
`vehicle theft notification and recovery, and remote diagnos-
`tics. For example, the data can indicate a vehicle’s location,
`its fuel level and battery voltage, and Whether or not it has
`any active DTCs. With these data a call center can dispatch
`a tow truck with the appropriate materials (e.g., extra
`gasoline or tools required to repair a specific problem) to
`repair the vehicle accordingly.
`The primary electrical components of certain embodi-
`ments of the wireless appliance, i.e. circuitry for OBD—II
`communication, power management, battery, GPS, and
`wireless transmission, may be each integrated into a unique
`custom ASIC and housed on a single substrate. Likewise, the
`antennae for both the GPS and wireless transmitter may be
`integrated into the substrate. As such, the wireless appliance
`may take the form of a stand-alone unit that can be easily
`installed and hidden in the host vehicle. This reduces instal-
`lation costs of the appliance and additionally makes it more
`diflicult to disable when stealing a vehicle.
`Moreover, integrating multiple conventional circuits into
`custom ASICs reduces manufacturing costs and increases
`reliability of the appliance. Specifically, the ASICs replace
`conventional discrete circuit components (e.g., resistors and
`capacitors) that are expensive and time-consuming to fab-
`ricate on a printed circuit board, and that tend to fail over
`time due to heat and vibration. This ultimately increases the
`cost effectiveness and reliability of the wireless appliance.
`A wireless appliance according to embodiments of the
`present invention can also be easily transferred from one
`vehicle to another, or easily replaced if it malfunctions. No
`additional wiring is required to install the appliance; it is
`powered through the vehicle’s OBD—II connector (assuming
`that such a connector is present in the vehicle) and using a
`back-up battery. The appliance can also be connected
`directly to a vehicle’s electrical system,
`thus making it
`unnecessary to even use an OBD—II connector.
`Embodiments of the present invention may be useful in a
`wide range of vehicles. Examples of such vehicles include
`automobiles and trucks, as well as commercial equipment,
`heavy trucks, power sport vehicles (e.g., motorboats,
`motorcycles, all-terrain vehicles, snowmobiles, jet skis, and
`other powered sport vehicles), collision repair vehicles,
`marine vehicles, and recreational vehicles. Further, embodi-
`ments may be useful in the vehicle care industry.
`Although OBD—II diagnostic systems are disclosed herein
`for illustrative purposes, it is to be appreciated that embodi-
`ments of the present invention may be employed with other
`systems.
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`US 6,957,133 B1
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`5
`FIG. 1A is a schematic drawing of a small-scale wireless
`appliance 10 according to an embodiment of the present
`invention. The wireless appliance 10 includes a micropro-
`cessor 8, a vehicle-communication circuit 4, a GPS module
`2, and a wireless transmitter 9. The wireless appliance 10
`may be installed in a vehicle.
`The GPS module 2 generates location-based data.
`The vehicle-communication circuit 4 collects diagnostic
`data relating to the vehicle. In an embodiment, the vehicle-
`communication circuit 4 includes modules 6a, 6b, .
`.
`.
`, 611
`for managing different vehicle-communication protocols,
`such as, for example, J1850 PWM, J1850 VPWM, ISO
`9141-2, CAN, Keyword 2000, and J1708. As such,
`the
`vehicle-communication circuit 4 may collect data from any
`vehicle that utilizes a protocol among those supported by
`modules 6a, 6b,
`.
`.
`.
`,
`611.
`In an implementation,
`the
`vehicle-communication circuit is integrated into a single
`ASIC.
`
`The microprocessor 8 is in electrical communication with
`the GPS module 2, the vehicle-communication circuit 4, and
`the wireless transmitter 9.
`The wireless transmitter 9 receives and transmits location-
`based data generated by the GPS module 2 and diagnostic
`data collected by the vehicle-communication circuit 4.
`FIG. 1B shows a small—scale wireless appliance 13
`according to an embodiment of the present invention that
`monitors diagnostic and location-based data from a host
`vehicle and wirelessly transmits these data to an Internet-
`accessible website. The wireless appliance 13 features: (1) a
`data-generating portion 15 that generates both diagnostic
`and location-based data; (2) a data-processing portion 17
`that processes and wirelessly transmits the diagnostic and
`location-based data; and (3) a power—management portion
`19 that supplies power to each circuit element in the appli-
`ance. The circuit elements in each portion 15, 17, 19,
`described in more detail below, are each integrated into
`small-scale, silicon-based microelectronic devices (e.g.,
`ASICs). This means that the entire wireless appliance 13 can
`be incorporated into a single ‘chip set’, described by a
`reference design, thereby reducing its size, manufacturing
`costs, and potential post-installation failures.
`The data-generating portion 15 features a chipset-based
`GPS module 20 that receives wireless signals from orbiting
`GPS satellites through an integrated GPS antenna 21. To
`reduce cabling in the wireless appliance 13 and costs asso-
`ciated with its installation, the integrated GPS antenna 21
`may attach to a metal ground plane within the appliance.
`Once the antenna 21 receives signals from at least three
`satellites, the GPS module 20 processes them to calculate a
`GPS ‘fix’ that includes the host Vehicle’s location-based
`data, e.g. latitude, longitude, altitude, heading, and velocity.
`The GPS module 20 calculates location-based data at a
`programmable interval, e.g. every minute.
`The data-generating portion 15 communicates with the
`host vehicle through an electrical/mechanical interface 23
`that connects to the vehicle’s 16-cavity OBD-II diagnostic
`connector. The diagnostic connector,
`typically located
`underneath the vehicle’s steering column, provides direct
`access to diagnostic data stored in memory in the vehicle’s
`ECU. The entire vehicle-communication circuit 25 is inte-
`grated into a single ASIC and manages communication
`through the electrical/mechanical interface 23 with separate
`modules 25a—25e for different vehicle buses (e.g.,
`those
`featured in Ford, GM, Toyota). Each module 25a—25e is a
`separate integrated circuit within the vehicle-
`communication circuit 25. FIGS. 5-7, described in detail
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`below, show detailed schematic drawings of embodiments
`of both the vehicle-communication circuit and some of the
`modules included therein. The modules feature circuit ele-
`ments that communicate according to vehicle-specific
`protocols, described below with reference to Tables 1 and 2.
`The vehicle-communication circuit additionally includes
`logic that detects the communication protocol of the host
`vehicle, and then selects this protocol to communicate with
`the vehicle. Once the protocol is selected,
`the electrical/
`mechanical interface 23 receives diagnostic data from the
`vehicle and passes it through the vehicle-communication
`circuit 25 to the data-processing portion 17 for analysis.
`It is to be appreciated that the specific protocols supported
`by the vehicle-communication circuit 25 of FIG. 1B are
`merely examples. In some embodiments, more, fewer, or
`other protocols may be supported by a vehicle-
`communication circuit.
`
`The data-processing portion 17 features a 16-bit ARM7
`microprocessor 27 that receives and processes diagnostic
`data from the data-communication circuit 25 and location-
`based data from the GPS module 20. For example,
`the
`microprocessor 27 can process diagnostic data describing
`the host vehicle’s speed, mass air flow, and malfunction
`indicator
`light
`to calculate,
`respectively, an odometer
`reading, fuel efliciency, and emission status.
`The microprocessor 27 additionally stores firmware and
`pre and/or post-processed diagnostic data in a memory
`module 29. The memory module 29 additionally stores an
`operating system (e.g., Linux) that runs on the micropro-
`cessor 27. During operation, the memory module can addi-
`tionally function as a ‘data logger’ where both diagnostic
`and location-based data are captured at high rates (e.g.,
`every 200 milliseconds) and then read out at a later time.
`With firmware the microprocessor 27 formats the diag-
`nostic and location-based data into separate packets and
`serially transfers these packets through a universal modem
`adaptor 35 to a wireless modem 31. Each formatted packet
`includes, e.g., a header that describes its destination and the
`wireless modem’s numerical
`identity (e.g.,
`its ‘phone
`number’) and a payload that includes the data. The wireless
`modem 31 operates on a wireless network (e.g., CDMA,
`GSM, GPRS, Mobitex, ORBCOMM) and transmits the
`packets through an antenna 33 to the network. The antenna
`33 is typically embedded into a circuit board or mechanical
`housing that supports the wireless modem 31. Once
`transmitted,
`the packets propagate through the network,
`which delivers them to an Internet-accessible website, for
`example, as described in more detail with reference to FIG.
`2.
`
`The universal modem adaptor 35 provides power,
`mechanical support, and a serial interface to the wireless
`modem 31 through a multi-pin mechanical connector 37.
`The connector’s pin configuration powers and supports a
`variety of different modems that, in turn, can operate on
`different wireless networks. One modern (e.g. a Mobitex
`modem) can be easily replaced with another (e .g., a satellite
`modem) that has better wireless coverage within a particular
`region. The firmware running on the microprocessor 27 is
`configured to recognize the wireless modem 31 attached to
`the universal modem adaptor 35 (using, e.g., the modem’s
`electronic serial number) and format outgoing packets
`accordingly. In this way the wireless appliance can be easily
`configured to operate on different wireless networks
`throughout the world.
`The power—management portion 19 of the wireless appli-
`ance 13 features a power supply and power-conditioning
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`US 6,957,133 B1
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`7
`electronics 39 that receive 12 volts DC power from the
`electrical/mechanical interface 23 and, in turn, supply regu-
`lated DC power to circuit elements in the data—generating 15
`and data—processing 17 portions. Typically the 12 volts from
`the vehicle’s battery is switched to a lower voltage, e.g.,
`3.3—5 volts, to power the circuit elements. The mechanical
`interface 23, in turn, attaches to the host vehicle’s diagnostic
`connector, which receives power directly from the vehicle’s
`standard 12-volt battery. An internal battery 41 connects to
`the power supply and power—conditioning electronics 39 and
`supplies power in case the wireless appliance is discon-
`nected from the vehicle’s power-supplying diagnostic con-
`nector. Additionally,
`the power supply and power-
`conditioning electronics 39 continually recharge the internal
`battery 41 so that it can supply back-up power even after
`extended use.
`
`FIG. 2 shows a schematic drawing of an Internet-based
`system 52 that uses the above-described wireless appliance
`13, or related embodiments thereof, to monitor both diag-
`nostic and location-based data from a host vehicle 12. The
`wireless appliance 13 connects to the vehicle’s OBD-II
`diagnostic connector 51 and collects diagnostic data by
`querying the vehicle’s ECU 55 through a cable 56. In
`response to a query, the ECU 55 retrieves data stored in its
`memory and sends it along the same cable 56 to the wireless
`appliance 13. The GPS module in the wireless appliance 13
`measures the vehicle’s location-based data using an antenna
`21 that is typically integrated into the wireless appliance or
`hidden within the vehicle (e.g., under the vehicle’s
`dashboard). To calculate the vehicle’s location, the antenna
`21 collects signals 62 from an overlying constellation of
`GPS satellites 60 and sends these signals to the GPS module
`for processing.
`During operation, the wireless appliance 13 formats the
`diagnostic and GPS data in separate data packets and
`transmits these packets through an embedded radio antenna
`33 over an airlink 59 to a base station 61 included in a
`wireless network 54. As described above,
`the embedded
`antenna 33 is typically included in a mechanical housing or
`circuit board used in the wireless appliance. The data
`packets propagate through the wireless network 54 to a
`gateway software piece 55 running on a host computer
`system 57. Using the gateway software piece 55, the host
`computer system processes and stores data from the data
`packets in a database 63. The host computer system 57
`additionally may host a web site 66 that, once accessed,
`displays the data. A user (e.g. an individual working for a
`call center) accesses the web site 66 with a secondary
`computer system 69 through the Internet 67.
`FIG. 3 shows a sample web page 130 included in the
`website of FIG. 2, for example, that displays diagnostic data
`collected from the ECU of a particular vehicle as described
`above. The web page 130 includes a set of diagnostic data
`131 and features fields listing, for example, an acronym 132,
`value and units 134, and brief description 136 for each
`datum. During typical operation,
`the wireless appliance
`automatically transmits sets of diagnostic data 131 like the
`one shown in FIG. 3 at periodic intervals, e.g. every 20 to 40
`minutes. The Wireless appliance can also transmit similar
`data sets at random time intervals in response to a query
`from the host computer system (sometimes called a ‘ping’).
`FIGS. 4A and 4B show sample web pages 150, 152
`included in the website of FIG. 2, for example, that display,
`respectively, GPS data 154 and a map 158 that together
`indicate a vehicle’s location 156. In this case, the GPS data
`154 include the vehicle’s latitude,
`longitude, a ‘reverse
`geocode’ of these data indicating a corresponding street
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`address, the nearest cross street, and a status of the vehicle’s
`ignition (i.e., ‘on’ or ‘o ’ and whether or not the vehicle is
`parked or moving). The map 158 displays these coordinates
`in a graphical form rela ive to an area of, in this case, a few
`square miles. In typical embodiments, the web pages 150,
`152 are rendered each time the GPS data are periodically
`transmitted from a vehicle (e.g., every 1-2 minutes) and
`received by the data—processing component of the website.
`Both the map and a database that translates the latitude and
`longitude into a reverse geocode are accessible though an
`Internet-based protocol, e.g. XML, Web Services, or TCP/IP.
`Companies such as MapTuit, MapQuest, and NavTech sup-
`port software that provides such maps and databases.
`As described above, the vehicle-communication circuit 25
`in FIG. 1B is a custom ASIC that features individual
`modules for managing communication protocols for differ-
`ent vehicles. Table 1, below, summarizes protocols for J1850
`PWM/VPWM and ISO 9141-2, their baud rate and pulse
`width specifications, and a representative sample of vehicles
`that support the protocol.
`
`TABLE 1
`
`Communication Protocols for Vehicles
`
`Protocol
`J1850 PWM
`J1850 VPWM
`ISO 9141-2
`
`Vehicle
`Ford
`GM, Chrysler
`Toyota, Chrysler
`
`Baud Rate (kbits/s)
`41.6
`10.4
`10.4
`
`Pulse Width
`constant
`variable
`constant
`
`These protocols are also described in detail in the follow-
`ing publications listed in Table 2.
`
`TABLE 2
`
`Protocol
`Reference
`Source
`Protocol
`Reference
`Source
`
`References Describing Vehicle-Communication Protocols
`J1850 PWM and J1850 VPWM
`‘Implementing the J1850 Protocol’
`ftp://download.intel.com/design/intarch/papers/j1850 wp.pd.f
`ISO 9141-2
`‘Automotive ISO 9141 Serial Link Driver’
`http://roadrurmeresng.dibe.unigc.it/EESS.Kit/
`Software%2Oe%2DdoCun1entazione/
`Data%20sl1eets%20componenti%20elettronici/
`IC%20Analogici/mc33199rev0f.pdf
`
`FIG. 5 shows a schematic diagram of an ASIC 175 and
`microprocessor 27 according to an embodiment of the
`present invention. ASIC 175 is used for the vehicle com-
`munication circuit 25 that connects to the host vehicle
`through a mechanical/electrical interface to the vehicle’s
`OBD-11 diagnostic port. The ASIC 175 features separate
`modules 25a—e that
`individually support communication
`protocols for J1850 VPWM, J1850 PWM, ISO-9141, CAN
`(e.g., ISO-15765), Keyword 2000, and J1708, for example.
`The ASIC 175 includes an internal microcontroller 177 that
`
`the ARM7
`connects to an external microprocessor (e.g.,
`microprocessor 27 in FIG. 1B) through a data link 179, e.g.
`an asynchronous serial channel. The microcontroller 177
`additionally connects to and receives data from each
`vehicle-communication module 25a—e through a first set of
`general-purpose input/output (GPIO) pins 180. Asecond set
`181 of GPIO pins in the microcontroller control a multi-
`plexer 178. The multiplexer 178 contains a third set of pins
`182 that switch between the five vehicle-communication
`modules 25a—e.
`
`During operation, the microprocessor 27 determines the
`communication protocol of the host vehicle, such as by
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`US 6,957,133 B1
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`9
`monitoring the baud rate and pulse width characteristics of
`the host vehicle’s communication protocol
`through the
`mechanical/electrical interface. In another embodiment, the
`microprocessor determines the communication protocol of
`the host vehicle by testing each protocol in an effort to
`establish communication. The microprocessor then selects
`the protocol
`that successfully communicated with the
`vehicle. In still another embodiment, the microprocessor is
`configured to test outputs of a diagnostic system in the host
`vehicle. For example, the microprocessor may test whether
`respective output pins of a diagnostic connector are active.
`Certain communication protocols use a predetermined sub-
`set of output pins for communication. Therefore, the pres-
`ence of electrical signals on a particular subset of output pins
`may indicate that the host vehicle is utilizing the vehicle-
`communication protocol associated with that particular sub-
`set.
`
`After the host vehicle’s vehicle-communication protocol
`is determined, the microprocessor 27 then communicates the
`protocol to the microcontroller 177 over the data link 179.
`Using two pins in the third set of pins 182, the multiplexer
`178 selects one of the five modules 25aw to communicate
`with the host vehicle. A third pin in the third set of pins 182
`either enables a module by providing power, or disables a
`module by removing power. In this way, the multiplexer 178
`effectively selects the module that is used to communicate
`with the host vehicle.
`
`FIGS. 6 and 7 show, respectively, logic diagrams 200, 210
`used for vehicle-communication modules supporting the
`J1850 PWM/VPWM and ISO 9141-2 protocols described
`above according to embodiments of the present invention.
`As indicated above in FIG. 5, these logic diagrams represent
`circuits that function as individual modules within the
`data-communication circuit and are integrated directly into
`the ASIC.
`
`Other embodiments are also within the scope of the
`invention. In particular, logic diagrams and corresponding
`circuits other than those described above can be used to
`implement protocols such as J1850 PWM/VPWM, ISO
`9141-2, CAN, Keyword 2000, and J1708. These protocols
`can be implemented using integrated silicon-based solutions
`(e.g., a custom ASIC), or using transistors or conventional
`circuit elements. Similarly, hardware architectures other
`than that described above can be used for a wireless appli-
`ance such as wireless appliance 13. For example, the ARM7
`microprocessor used to run the appliance’s firmware may be
`contained within the GPS module or the wireless modem. Or
`a different microprocessor may be used. And the antennae
`for both the modem and the GPS module can be imple-
`mented using different configurations. In one embodiment,
`for example, either or both antennae may be implemented as
`discrete circuits directly onto the circuit board. Similarly,
`active antennae, which are conventionally used for GPS,
`may also be used for the radio antenna connected to the
`wireless modern. In another embodiment, the internal bat-
`tery may be a solar cell.
`In yet another embodiment, a wiring harness may be used
`to attach the wireless appliance to the vehicle’s OBD-II
`diagnostic connector. This allows the wireless appliance to
`be hidden in the vehicle, thereby making the device effective
`for recovery of stolen vehicles.
`The packets described above may be transmitted at pre-set
`time intervals (e.g., once every 20 minutes for diagnostic
`data; once every minute for GPS data). Alternatively or
`additionally,
`the transmission may be performed when
`authorized by a user of the system (e.g., using a button on
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`the website). In still other embodiments, the transmission is
`performed when a data parameter (e.g. engine coolant
`temperature) exceeds a predetermined value. Or a third
`party, such as the call center, may prompt
`transmission
`and/or analysis of data.
`In other embodiments, a radio modern used to transmit
`GPS data may employ a terrestrial GPS system, such as a
`‘network-assisted’ GPS available on chipsets designed by
`Qualcomm, Inc. In this case GPS data is determined by
`processing data from both satellites and terrestrial base
`stations. In addition, the wireless appliance may be inter-
`faced to other sensors deployed in th