transmission of sequences of representative values ​​from measurements of sensors associated with a pneumatic system to a remote receiving device

Abstract

A method for communicating values ​​measured by at least one sensor (21, 22, 23) of a device (20) associated with a pneumatic (11) to a remote receiving element (30), comprising the steps of: acquiring (S1) measurements by the at least one sensor; sampling (S2) and storing (S3) said measurements to form an ordered series; determining (S4) a sequence of values ​​from said ordered series; and transmitting (S5) a frame (40) to the remote receiving element (30), comprising a unique identifier (441) of the device, an increment indicator (442), a format indicator (444) of the value sequence, and this value sequence (443), the latter comprising at least one reference value and a set of representations of other values ​​in the form of a deviation relative to the reference value. Figure for the abbreviation: Figure 1

Description

Title of the invention: Transmission of sequences of representative values ​​from measurements of sensors associated with a pneumatic system to a remote receiving device. Technical field

[0001] This description relates to the transmission of measurement data between a device associated with a mounted assembly comprising a tire and a wheel, and a remote receiving element. It applies particularly to devices comprising sensors, such as temperature or pressure sensors, measuring the condition of the tire.

[0002] It is already known to have sensors on vehicle tires such as TPMS (Tire Pressure Monitoring System) devices, which are tire pressure monitoring systems. They use sensors installed inside or outside the tires to measure the pressure; these measurements are then transmitted wirelessly to an electronic component of the vehicle in order to warn the driver in case of a pressure problem.

[0003] More recently, more complex systems have emerged for tire management, the TMS (“Tire Mounted System” in English) systems which aim to multiply the sensors and provide advanced functionalities through the measured data.

[0004] However, due in particular to the increasing number of sensors and the growing volume of data to be transmitted, various technical problems arise. These problems are mainly related to the energy consumption of these electronic devices, and also to radio transmission issues between them and the remote receiving device.

[0005] Each transmission of a frame to the remote component generates energy consumption. However, for the most efficient pneumatic system management, it is important to have a significant amount of data available for the receiving component, possibly of different types (pressure, temperature, etc.). Increasing the amount of data necessarily leads to an increase in the number of frames to be transmitted and therefore in the energy consumption of the electronic device.

[0006] However, the electronic device is a device associated with a tire that cannot be connected by wire to the vehicle in industrial mode. It must therefore necessarily be electrically powered by a battery. Its autonomy thus depends essentially on the capacity of this battery and its electrical consumption. The electronic device may also be difficult to access, or even impossible to access at all if it is positioned inside a tire, so that it is not possible or desirable to change this battery.

[0007] There is therefore a need to improve current prior art proposals in order to minimize the energy consumption of the electronic device. Description of the invention

[0008] The proposals described therefore aim to improve the situation compared to those of the prior art, and in particular, to reduce the energy consumption of the device associated with the tire.

[0009] To this end, according to a first aspect, a method is proposed for communicating values ​​measured by at least one sensor of a device associated with a pneumatic system to a remote receiving organ, comprising the steps of:

[0010] acquisition of measurements by said at least one sensor;

[0011] sampling and storage of said measurements to constitute an ordered series;

[0012] determination of a sequence of values ​​from said ordered series

[0013] transmission of a frame to said remote receiving device, comprising a unique identifier of said device, an increment indicator, incremented on each transmission, an indicator of the format of said value sequence and said value sequence, said value sequence comprising at least one reference value and a set of representations of other values ​​in the form of a deviation relative to said reference value

[0014] According to preferred embodiments, the process comprises one or more of the following features which may be used separately or in partial or total combination: - said sequence of values ​​is determined so as to partially overlap a previous sequence. - each element of the set of representations of the sequence of values ​​corresponds to the absolute value of a relative deviation multiplied by a multiple of two to which has been added or subtracted the value one to the smallest unit of representations of said relative deviation according to one of the two possible signs for said relative deviation. - said sequence of values ​​includes values ​​from different sensors and / or corresponding to different sampling periods. - said device is positioned on an inner surface of said tire or on a rim associated with said tire or on a valve associated with said tire. said frame is transmitted according to the BLE protocol, specifically in an announcement channel

[0015] Another aspect concerns a device suitable for use with a tire, comprising: circuits adapted to sample measurements acquired by sensors; a memory for storing said measurements to form an ordered series, said circuits being further adapted to determine a sequence of values ​​from said ordered series and to transmit, in conjunction with a radio frequency interface, a frame to a remote receiving device, comprising a unique identifier of said device, an increment indicator, incremented during each transmission, a format indicator of said sequence of values, and said sequence of values, said sequence of values ​​comprising at least one reference value and a set of representations of other values ​​in the form of a deviation relative to said reference value

[0016] Another aspect concerns an assembled unit, or wheel, comprising at least one device as previously described.

[0017] Another aspect relates to a computer program suitable for implementation on a device, the program comprising code instructions which, when executed by a processor, carries out the steps of the process as previously defined.

[0018] Another aspect relates to a data carrier on which at least one series of program code instructions for the execution of a process as previously defined has been stored. Brief description of the drawings

[0019] Other aspects, objectives, advantages and features of the invention will become more apparent upon reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0020] Figure 1 represents a context for the implementation of the process and devices described.

[0021] Fig. 2 schematically represents the architecture of a device according to one embodiment.

[0022] Figure 3 illustrates an illustrative flowchart of a process according to a method of realization.

[0023] Figure 4 illustrates an example of a frame transmitted between a device and a remote receiving organ, according to embodiments.

[0024] Figure 5 illustrates an example of a payload of a frame transmitted between a device and a remote receiving organ, according to embodiments.

[0025] Figure 6 illustrates a concrete example of a succession of frames transmitted by a device, according to one embodiment.

[0026] DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0027] Figure [Fig. 1] shows a mounted assembly, or wheel, 10 comprising a tire 11 and a rim 12. The wheel is intended to be mounted on a motor vehicle.

[0028] A device 20 is associated with the tire 11, that is to say, adapted to provide information on the condition of this tire by means of sensors. This device is an electronic device. It is, for example, a TPMS or TMS device or any other device of the same type having similar functionalities.

[0029] The device 20 can be positioned directly on or within the tire 11. In particular, this device can be positioned and fixed on an inner surface of the tire. The device 20 can also be positioned on the rim 12, or on a valve associated with the tire. Generally, the device 20 is secured to the mounted assembly 10.

[0030] This device is adapted to communicate measurements acquired by the sensors to a remote receiving organ 30.

[0031] This remote receiving device 30 can be located in the motor vehicle. For example, it could be circuits within the set of circuits constituting the vehicle's dashboard. It can then be designed to allow the display of data from these measurements on an interface of this dashboard, in the form of numerical values, indicator lights in case of alarms (determined by exceeding thresholds, for example), etc.

[0032] The remote receiving unit 30 may also be located outside the vehicle. For example, it may be located in a station where the motor vehicle may be parked periodically. This could be a regular parking area for the vehicle, or a maintenance area, for example.

[0033] The measurement communication can be achieved by transmitting a data frame 40 to this remote receiving device. This frame 40 includes, in particular, representative values ​​of these measurements, adapted for processing by the remote receiving device 30.

[0034] Fig. 2 schematically illustrates a possible architecture of such a device 20.

[0035] In this embodiment, sensors 21, 22, 23 are integrated into the structure of the device. Other embodiments may consist of having sensors located outside the device itself and capable of communicating with it by wired or radio means, for example by near-field communication (NFC). (for "Near Field Communication" in English). In this example, 3 sensors are shown, but it is obviously possible to have fewer or more sensors.

[0036] The device also includes processing means 24, or electronic circuits, typically comprising a microcontroller, or processor, and a memory 25.

[0037] The device 20 further comprises a radio frequency interface 26 adapted for transmitting frames 40 to the remote receiving unit 30. This radio interface 26 can conform to various radio communication mechanisms and protocols. In particular, it can conform to short-range radio communication protocols such as Wi-Fi or Wi-Fi Direct, Zigbee, Z-Wave, Bluetooth, or BLE.

[0038] In the case where the transmission itself must minimize the energy consumption of the transmitting device 20, the BLE protocol may be chosen.

[0039] The “Bluetooth Low Energy” (BLE) protocol is a version of the Bluetooth protocol designed to provide low-power wireless communications. BLE is standardized in the IEEE 802.15.1 standard and is part of the Bluetooth specifications adopted by the Bluetooth Special Interest Group (Bluetooth SIG).

[0040] The BLE protocol uses frequency bands of 2.4 GHz and 40 channels distributed between 2402 and 2480 MHz and with a width of 2 MHz.

[0041] According to this protocol, three advertising channels are provided. These are specific channels used for broadcasting advertising messages or frames, particularly for the purpose of establishing a connection: devices listening on these channels can receive advertising messages, which allows a device to initiate a connection. They can also be used to announce its presence (discovery mechanism) or for beacon-type signaling. Data is exchanged between participants after a connection is established, in frames transmitted over the other channels.

[0042] Advertisement frames, transmitted by advertisement channels, are thus opposed to data frames transmitted by other channels.

[0043] The advertising channels are channels 37 (2402 MHz), 38 (2426 MHz) and 39 (2480 MHz). These three channels are strategically located within the frequency band to minimize interference with other technologies using the same band (such as Wi-Fi, which also operates in the 2.4 GHz band).

[0044] Establishing a connection between two parties in a BLE communication poses an energy consumption problem, particularly due to the synchronizations to be performed between them and multiple frequency hops to be performed to transmit and listen in the correct channels.

[0045] Also, according to an embodiment based on this BLE protocol, it is chosen not to establish a connection between the device 20 and the remote receiving organ 30. In particular, the frames 40 are transmitted on an advertisement channel.

[0046] Figure 3 illustrates a flowchart of the described process, according to one embodiment. This flowchart shows a breakdown into steps given for illustrative purposes; it may be possible to subdivide certain steps, aggregate some, or proceed with another breakdown allowing the same final functionality.

[0047] According to this embodiment, a step SI consists of acquiring measurements by the sensor(s) 21, 22, 23. A preliminary step may consist of setting up the measuring device within the assembled unit.

[0048] These sensors may include a pressure sensor. They may also include a temperature sensor, an accelerometer, a rotation sensor, etc. The proposed method is independent of the number and type of sensors considered.

[0049] In a step S2, these measurements are sampled. The sampling process depends in particular on the format of the measurements acquired by the sensors. The sampling frequency is variable; it may depend, in particular, on the type of measurements and their estimated rate of change. These sampling rates can be set during a parameterization phase of the device 20. According to one embodiment, the device 20 may be adapted to receive a parameterization message (for example, emitted by the remote receiving element 30, which would then also be a transmitter) specifying these sampling rates.

[0050] These sampled measurements are then stored, in a step S3, in a memory 25 of the device 20, by the processing circuits 24. An ordered series is thus formed in which each measurement corresponds to a time, or date, according to the sampling chosen.

[0051] In a step S4, a sequence of values ​​is determined from the stored ordered series, with a view to its transmission, in a step S5 within the frame 40 to the remote receiving organ 30.

[0052] Since this frame is of limited size, it is necessary to define an encoding of the measurements so that the transmitted values ​​allow a larger number of measurements to be transmitted.

[0053] In the case of an implementation in which the frames are transmitted on BLE protocol advertising channels, as illustrated in [Fig. 4], this frame 40 comprises a preamble 41 of one byte, an address field 42 of four bytes, a header 43 of two bytes, and a payload 44 (or PDU for "Protocol Data Unit" (Protocol Data Unit). The frame also includes a 3-byte 45-byte error correction code (CRC).

[0054] Preamble 41 is a synchronization field used to indicate the start of the frame.

[0055] For advertisement frames, address field 42 is fixed and has the value 0x8E89BED6. For data frames, this address is unique to the current connection between two devices.

[0056] Header 43 indicates the type of frame: for example, a "connectionless communication" type for an advertisement frame. For such a frame, it also indicates the length of the payload 44, which can be between 0 and 37 bytes.

[0057] Also, the transmission of the sequence of values ​​is constrained in this payload to a maximum of 37 bytes.

[0058] As illustrated in [Fig.5], part of this payload 44 is also used for other information as will be seen later: an identifier 441 of the device 20, an increment indicator 442 and a format indicator 444. The sequence of values ​​then occupies only a part 443 of the payload 44.

[0059] This identifier of device 441 is a unique identifier, that is to say, allowing the device 20 to be identified in a unique way.

[0060] The order of the fields is illustrative.

[0061] Furthermore, transmission on an advertising channel assumes that the remote receiving device 30 is listening to that channel. If this device is a general-purpose device, it must listen to all the channels of the BLE protocol and can only receive a portion of the frames transmitted on the advertising channels.

[0062] Furthermore, the environment of the devices 20 causes interference with radio communications: use of the frequency band by other networks (Wi-Fi in particular), presence of the metal parts of the rim 12, rotation of the assembled unit 10, etc. As a result, a large number of frames 40 are not received by the remote receiving device 30.

[0063] However, since a bilateral connection is avoided, the radio link between device 20 and the remote transmitting unit 30 is unidirectional. It is therefore not possible for the latter to alert the device that it has not received certain frames 40. Moreover, such a request and such repetition would be detrimental since they would generate an additional load for device 20 and therefore an increase in energy consumption, which is precisely what is being avoided.

[0064] It is therefore proposed that the sequence of values ​​transmitted in the frames constitutes a history of the measurements. The remote receiving device 30, receiving such a frame, can thus access measurements corresponding to several dates and thereby determine the evolution over time of the measured quantity (pressure, temperature, etc.).

[0065] As mentioned previously, it may be possible to maximize the number of measurements represented by the sequence of transmitted values, so that a single frame brings a large amount of information to the remote receiving organ 30.

[0066] To do this, different encoding methods can be used.

[0067] Preferably, the measurements are converted into a unit that minimizes the number of digits required to represent them.

[0068] In particular, for pressure, a representation in bars will be preferred rather than in millibars or pascals, for example.

[0069] According to one embodiment, the measurements are encoded so that a sequence of values ​​includes at least one reference value and a set of representations of other values ​​in the form of a deviation relative to that reference value.

[0070] This embodiment is based on the fact that the changes in the measured quantities are slow and that the relative differences are therefore small. Their representation can therefore be encoded in a small number of bytes.

[0071] For example, the reference value can be encoded using 2 bytes and each relative deviation using 4 bits. Thus, if the sequence of values ​​is encoded using 18 bytes, a sequence of 33 values ​​can be encoded. This result can be compared with a conventional encoding in which each measurement would be represented by a value encoded using 2 bytes, which would have allowed only 9 values / measurements.

[0072] According to one embodiment, the encoding of relative deviations can be optimized by a method known as zigzag encoding. This encoding method avoids using a bit solely for the sign of the relative deviation.

[0073] This method consists of, for each element of the set of representations of the sequence of values, taking the absolute value of a relative deviation multiplied by a multiple of two, then adding or subtracting the value "1" to the smallest unit of representations of this relative deviation, according to one of the two possible signs of the relative deviation.

[0074] For example, we add or subtract "1" for the negative sign: negative relative deviations are thus transformed into odd values, while positive relative deviations, due to multiplication by a multiple of "2", are transformed into even values.

[0075] The smallest unit of representation can also be called the last significant digit or the last non-zero digit, whether this relative difference is an integer or a decimal number.

[0076] In other words, this method consists of performing the following manipulation on the relative difference: - if the relative difference is positive, we multiply it by two (or another multiple of two); - if the difference is negative, we multiply its absolute value by two (or another multiple of two) and add one (or subtract one) to the smallest unit of representation of the value.

[0077] Thus, for the distant receiving organ 30, it can test the parity of the encoded gap to determine if it is positive and negative, and perform the inverse manipulation to recover the relative gap, that is: - if the number is even, the relative difference is obtained by dividing by 2 (or another multiple of two), - If the number is odd, the relative deviation is obtained by subtracting (or adding) the value 1 to the smallest unit representing the value, then dividing by 2 (or another multiple of two). The relative deviation is the opposite of the value thus obtained.

[0078] For example, the value 3.14 is positive, so we can just multiply it by two for its encoding, which gives 6.28.

[0079] Since the value -3.14 is negative, we multiply its absolute value (6.28) by two and add 1 to the smallest unit of representation, or last digit (here 8): we thus obtain 6.29. As this value is odd, the receiver will be able to determine that it is a negative relative difference.

[0080] This allows us to gain encoding space to allow the value sequence to transmit more measurements and / or to improve the precision of each measurement represented (i.e. a number of useful bits per value).

[0081] As mentioned previously, maximizing the number of measurements represented by the sequence of transmitted values ​​allows the remote receiving organ 30 to obtain a large amount of information on the history of measurements.

[0082] Furthermore, it may be provided that the sequence of values ​​is determined so as to partially overlap a previous sequence. Typically, the sequence of values ​​partially overlaps the immediately preceding sequence. In other words, according to this embodiment, each frame 40 may include values ​​representing measurements already represented in a previous frame.

[0083] This embodiment makes it possible to reconstruct a more complete history even in the event of the loss of a frame 40, by taking advantage of this redundancy.

[0084] To do this, frames 40 may include an increment flag 442.

[0085] This increment indicator allows a frame 40 to be identified uniquely, modulo the size of this field 442, but which is designed so that two frames cannot have the same increment indicator within a sufficiently long time interval to generate ambiguity.

[0086] The increment indicator can be generated by means of a simple counter implemented by the circuits 24 of the device 20. During each transmission of a frame 40, this counter is incremented by one unit (it can be incremented before the transmission or after the transmission, according to operational choices).

[0087] Thus, the remote receiving organ 30 can use the increment indicator in order to position the received frames relative to each other, that is to say, to order them.

[0088] This increment number also makes it easy to determine which frames were not received.

[0089] Thus, the content of an unreceived frame can be reconstructed, at least partially, by the remote receiving organ 30, using the contents of the immediately preceding and following frames.

[0090] For example, it is assumed that 33 measurements are represented by the value sequences of each frame 40. An overlap rate of 33% is assumed. It can then be considered that - a Tl frame comprises a sequence of values ​​corresponding to measurements from ml to m33, - a T2 frame comprises a sequence of values ​​corresponding to measurements from m22 to m55, - a T3 frame comprises a sequence of values ​​corresponding to measurements m44 to m66.

[0091] If frame T2 is not received by the remote receiving device 30, it can nevertheless reconstruct a history from frames T1 and T3: [ml-m33 ; m44-m66]. The effect of the loss of frame T2 is thus minimized (interval [m33-m44]) due both to the redundancy of information transmission between several frames, and to the identification of frames that can be scheduled upon reception for the increment indicator 442.

[0092] Furthermore, as previously discussed, a device may include several sensors. The measurements from these different sensors must therefore be transmitted to the remote receiving unit 30.

[0093] According to one embodiment, a frame 40 transmits a sequence of values ​​corresponding to a single sensor, i.e. representing only pressure or temperature measurements, etc.

[0094] According to another embodiment, the sequence of values ​​can include values ​​from the different sensors. Thus, the sequence of values ​​is subdivided into sub-sequences, each corresponding to a sensor 21, 22, 23. For example, the 18-byte field 443 can be divided into 3 sub-fields, not necessarily of equal size, each corresponding to one of these sensors.

[0095] Furthermore, according to one embodiment, the sequence of values ​​may correspond to different sampling periods.

[0096] The variety of sampling periods makes it possible both to help reconstruct a measurement history in case of frame losses, but also to address distinct problems.

[0097] Thus, it is advantageous to have - a history of pressure and / or temperature measurements at short intervals in order to estimate load behavior at the coupling, but also - on a longer scale (for example, one pressure measurement over 8 hours or over 24 hours) to allow the detection of a slow leak, or - on an even longer scale (for example one measurement per day over 8 days or a month) in order to monitor the behavior and condition of a tire on a vehicle returning from a mission to the depot.

[0098] As with the different sensors, these different samples can be distributed in specific frames or within the same frame.

[0099] Thus, a sequence of values ​​may comprise a first part relating to a first sampling period and a second part relating to a second sampling period, for example. Other parts and sampling periods may also be added.

[0100] For example, a sequence of values ​​could include - The first 4 values ​​correspond to a one-hour sample, - the following 4 values ​​corresponding to a 4-hour sampling; - The following 4 values ​​correspond to a 16-hour interval.

[0101] Thus, if the remote receiving device 30 receives a frame 40 every hour, containing 16 values, it can reconstruct a 64-hour history with hourly accuracy.

[0102] It may be provided that the devices 20 can transmit frames according to one or more of the modalities described above.

[0103] In the latter case, a format indicator 444 (which may form part of the field 443 corresponding to the sequence of values) allows the frame type to be indicated and a format to be defined for this sequence of values ​​to be defined.

[0104] In particular, this format indicator can specify: - the type of measurement: pressure, temperature, acceleration, etc. - the unit of encoding these measurements: pascals, hectopascals, bars..., degrees Celsius, Fahrenheit... - the type of encoding: each measurement on a fixed number of bits, or encoding with a reference value and relative deviations - one or more sampling periods, and the corresponding subdivision of the sequence of values ​​according to these sampling periods, - etc.

[0105] For example, a given value for this field can refer to a catalogue of possible formats, which is shared by the device 20 and the remote receiving organ 30. In this way, by considering this format indicator 444, the latter can decode the entire sequence of values, so as to recover the encoded measurements.

[0106] The frame 40 thus prepared is then transmitted to the remote receiving device 30. As previously described, it can be transmitted in a BLE protocol advertising channel. However, other protocols are also conceivable, including future developments of this protocol, or other protocols based on the same principles.

[0107] Figure 6 illustrates a concrete example of a succession of T1, T2..T8 frames transmitted by a device 20.

[0108] On the x-axis are an ordered series of measurements (the numbers 1 to 28 representing an order of measurements, 28 representing the oldest measurement temporally).

[0109] Frames T1 to T8 are transmitted successively, in that temporal order. Frame T1 is the oldest transmitted.

[0110] Each frame corresponding to the same format (identical format identifier 444) which corresponds to 3 different sampling periods: a period of 1 for a duration of 5 measurements, then a period of 3, then a period of 6. Thus, the frame Tl includes measurements 8, 9, 10, 11, 12 (period of 1), 15, 18 and 21 (period of 3), and 27 (period of 6).

[0111] It is assumed that the T3 and T7 frames are lost (i.e. not received by the distant receiving organ 30).

[0112] The redundancy of the data present in each frame allows for the reconstruction of a majority of the data, particularly the most recent data. In this case, only measure 19 would be missing because it is (in the example) transmitted only by frame T3. Obviously, other frames before frame T1 or after frame T8 could also allow for the reconstruction of this measure 19, despite the missing data from frames T3 and T7.

[0113] More generally, the present proposals are not limited to the examples and embodiments described and illustrated. In particular, they are susceptible to numerous variations accessible to those skilled in the art, some of which have been described previously or simply mentioned.

[0114] Of course, the present invention is not limited to the examples and embodiment described and illustrated, but is defined by the claims. In particular, it is susceptible of numerous variations accessible to those skilled in the art.

Claims

Demands

1. A method for communicating values ​​measured by at least one sensor (21, 22, 23) of a device (20) associated with a pneumatic (11) to a remote receiving organ (30), comprising the steps of: acquiring (S1) measurements by said at least one sensor; sampling (S2) and storing (S3) said measurements to form an ordered series; determining (S4) a sequence of values ​​from said ordered series; transmitting (S5) a frame (40) to said remote receiving organ (30), comprising a unique identifier (441) of said device, an increment indicator (442), incremented at each transmission, an indicator of the format (444) of said sequence of values, and said sequence of values ​​(443), said sequence of values ​​comprising at least one reference value and a set of representations of other values ​​in the form of a deviation relative to said reference value.

2. A method according to the preceding claim, wherein said sequence of values ​​is determined so as to partially overlap a previous sequence.

3. A method according to any one of the preceding claims, wherein each element of the set of representations of the sequence of values ​​corresponds to the absolute value of a relative deviation multiplied by a multiple of two to which has been added or subtracted the value one to the smallest unit of representations of said relative deviation according to one of the two possible signs for said relative deviation.

4. A method according to the preceding claim, wherein said sequence of values ​​comprises values ​​from different sensors and / or corresponding to different sampling periods.

5. A method according to any one of the preceding claims, wherein said device (20) is positioned on an inner surface of said tire (11) or on a rim associated with said tire or on a valve associated with said tire.

6. A method according to any one of the preceding claims, wherein said frame is transmitted according to the BLE protocol, in particular in an advertising channel.

7. A computer program capable of being implemented on a device (20), the program comprising code instructions which, when executed by a processor, carries out the steps of the process defined in claims 1 to 6.

8. Device (20) suitable for being associated with a pneumatic (11), comprising - circuits (24) adapted for sampling measurements acquired by sensors (21, 22, 23) - a memory (25) for storing said measurements to constitute an ordered series, said circuits being further adapted for determining a sequence of values ​​from said ordered series and for, in collaboration with a radio frequency interface (26), transmitting a frame (40) to a remote receiving organ (30), comprising a unique identifier of said device (441), an increment indicator (442), incremented at each transmission, a format indicator (444) of said sequence of values, and said sequence of values ​​(443), said sequence of values ​​comprising at least one reference value and a set of representations of other values ​​in the form of a deviation relative to said reference value.

9. Assembled assembly (10) comprising a device (20) according to the preceding claim.

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