FR2719685A1 - Computer interface which permits pointing device to simulate mouse function - Google Patents

Abstract

The interface collects the signals (1,1) indicating the position and state (1,6) of buttons. The signals are amplified (1,2) and stored (1,3). They are then transformed (1,7) into position data which characterises a movement value. A unit (1,5) records the button state and detects any change. A unit (1,7) reassembles the data and codes it in a required form. A unit (1,8) emits at any required instant the data in the unit (1,7). The system is integrated in a pointer housing which generates the signals (1,1, 1,6) or in a independent housing. The power supply is taken from the computer or from an independent source.

Description

Interface allowing a pointing device
to simulate the operation of a mouse
The present invention relates to a device for replacing a mouse with another pointing device usually not provided for this purpose.

Computer-type computer peripherals output analog signals that are interpreted by an interface card plugged into the main board of the computer. These interface cards receive analog signals, transform them into digital data, and transmit them directly to the data bus of the computer. It is therefore not possible to use these devices when the correct card can not be added to the computer. This is the case with laptops and most workstations that have no room in their case
On the other hand, almost all computers offer the possibility of using an external mouse. The present invention allows another device to be connected in place of the mouse.

The data acquired at the input of the device can be of analog or digital type. The following description of the device was made by separating it into six functional modules. We can possibly combine these functional modules, invert the order, and consider not using some of them The six functional modules forming the device are (see diagram 1)
a module (1.2) for acquiring and amplifying the signals (1.1) coming from the peripheral;
a module (1.3) for decoding the input data (1.1). This decoding can consist of a conversion of analog signals into numeric values possibly signed. If the input signals (1.1) are digital or all-or-nothing, the decoding will rather consist of an interpretation and formatting in the form that is most useful to us;
a module (14) for transforming digital data representative of a position into digital data representative of a movement. We will see further what method to use for this transformation and what devices are needed to perform it;
a module (1.5) for managing additional signals (1.6) acquired as input, whether or not from the interface device. These signals can be digital or analog signals. For example, they can be buttons for the device. The module (1 5) delivers digital data characterizing the input signals (1.6), ie their current value or their value at the last reception of a signal from the module (1.8). This module may have functions other than the delivery of these digital data, in particular in the case where the number of signals (1.6) is too large;
a module (1.7) for formatting the data that one wishes to emit. This formatting module accepts data from modules (1.4) and (1.5). It uses this data to put it in the format corresponding to the communication protocol of the simulated mouse. We will later see that this formatting can be done in different ways for the same protocol, according to the preferred embodiment;
a module (1.8) which emits after possibly serializing the results leaving the module (1.7). This module is responsible for deciding whether to emit or not. Here again, the choice of the instant of the emission depends on the embodiment. The data will be serialized if the mouse management protocol that is simulated requires it. The data (1.9) issued by the module (1.8) are the only ones transmitted by the device.

Our device differs essentially from the electronic device commonly found in a mouse in that the input signals are characteristic of a position P and not of a movement M. Whereas the electronic device of the mouse receives sensors the amount of movement performed for a certain period, the signals acquired at the entrance of our device are characteristic of a position. This fundamental difference leads to the necessity of carrying out the transformation described below.

Hypotheses:
Let P = (Px, Py) be the characteristic vector of a position, and come from the signals acquired at the input. The components can be optionally signed. We denote PO = (POx, POy) the so-called rest position.

 Let M = (Mx, My) be the characteristic vector of a quantity of motion that one wishes to obtain after transformation. The Mx and My components can also be signed.

 Let ai, a2, bl, b2, cl and c2 be parameters whose value is not imposed. However, we see that the absolute values of al and a2 are used to calibrate the value of the result. The choice of the sign of al and a2 is also important because it allows to give opposite signs to the components of M and P as needed.

Formula: Mx = ai (b1 Px-POx) + c1
My = a2 (b2 Py - POy) + c2
In practice, it is essential for the proper functioning of the device that the value of PO can really be considered as representative of the rest position.

Note that the transformation was presented using a two-component P vector as a two-component M vector because it is the most common configuration. This formula obviously extends to the case of the transformation of an n-component vector P into an n-component vector M. The case of a transformation of a vector P a n components into a vector M with m components where m and n have different values is also possible but goes beyond the scope of this presentation.

The formatting of the data packet in the format as it would be if the packet came from a mouse is done using Mx, My and possibly other signals (1.6 in Figure 1) corresponding to the state of buttons. We will call S the vector whose components are characteristic of these latter signals.

Four alternatives can be envisaged when formatting and sending data packets.

 A.1) The data packets simulating the mouse are transmitted at regular intervals to the signal of a clock and are constructed by directly using the values of Mx, My and S.

 A.2) The transmitted data packets are constructed as in 1) using M'x, M'y and S, but M'x and M'y are preexisting values and selected according to the value of Mx and My. The data packets are then emitted at intervals proportional to Mx2 + My2 or to IMx1 + lMyl, or to any other combination of the components of M and S.

A.3) Case A.1, but no packet is sent when the input signals are equal to a reference value called "idle state"
A.4) Case A.3, but the packets are still issued if the value of one of the components of S has changed since the last broadcast
The format in which the formatting is done depends entirely on the type of mouse whose operation is to be simulated. The data resulting from this formatting can be entirely, partially or not at all pre-existing. The formatting can therefore be done in several ways according to the alternative (A1 to A4) that we adopt.

The transmission of the data delivered by the formatting module can be done "in series" or "in parallel" The transmission module must possibly be able to perform this serialization. He must also decide whether or not to send the data. Whatever the alternative A1, A2, A3 or A4, there will be emission at least if the value of one of the components of the vector S has changed since the last transmission (this information is obtained via the module (1.4 For Al A3 and A4 alternatives there will also be an issue if one of the data to be transmitted has changed since the last issue.For Alternative A3, there will be an issue if the duration since the last issue is considered sufficient. .

Each of the functional modules mentioned and described above can be realized by means of printed or integrated electronic circuits, possibly programmed, and combined with conventional electronic components. In particular, it should be noted that it is possible to use a microcontroller. Finally, let us add that our device can be removable or physically integrated in the pointing device and that it can draw a source of electricity in the connection with the computer to which it is connected, or by another means (battery or electrical socket) , or by a combination of both Our device must also be able to transmit some of the electrical energy available to the pointing device which it acquires the data.

The present invention can be adapted for any pointing device delivering one or more signals, analog or not, characteristic of a position and not a displacement, it can be in particular made for the use of a joystick (more commonly called joystick) analog.

In this case, the analog signal received at the input of the device is an electrical current of which one of the characteristics (voltage, intensity) varies. Two signals of this type are accepted at the input of the device as well as other inputs denoting the state of buttons. format of data packets delivered at the output can be adapted to any protocol Packets can be serialized or not
The descriptions below show the adaptation of the present invention to the case of the interconnection of an analog IBM PC-compatible computer analog joystick with the serial port called "mouse port" managed according to the "Miçrosoft" protocol ( the name of the company
Microsoft) mouse management.

According to the "Microsoff" mouse management protocol, the mouse must emit three octet-sized data packets (eight bits) at each mouse movement event, pushing a button, releasing a These three bytes sent in series by the mouse have the following format
D7 D6 D5 D4 D3 D2 D1 W
01 1 1 BD BG Y7 Y6 X7 X6
02 1 0 X5 X4 X3 X2 X1 XO
03 1 0 Y5 Y4 Y3 Y2 Y1 YO
The three bytes are transmitted in the order 01, 02, 03, bit D7 first (then D6 to W). The bits BG and BD are respectively for the left and right buttons of the mouse; they take the value O when the corresponding button is pressed and 1 when it is released. The signed byte formed by the bits X7 to XO (XO being the least significant bit and X7 the sign) indicates the amount of movement made by the mouse on the left / right axis since the last data transmission. The byte is positive if and only if the mouse went to the right, negative if and only if it went to the left and no if and only there has been no movement since the last show. byte Y 7 YO for the high-low axis is positive if and only if the mouse is pointing downwards, negative if and only if it is pointing downwards and null if there has been no displacement.

Figure 2 shows the embodiment of the invention for this configuration
The input currents (2.1 and 2.2) of the device are amplified by means of variable resistors or operational amplifiers (2.3 and 2.4) connected in series, this amplification making it possible to adjust the sensitivity of the device; the amplifiers (2.3) and (2.4) must therefore be able to be handled from the outside, the results of this amplification being respectively (2.5) and (2.6).

 - (2.5) and (2.6) are each redirected to an analoginumeric converter. The values delivered by these two converters (2.7) and (2.8) are unsigned bytes (by arbitrary choice: these values could have been signed). These converters are such that the value (2.9) delivered by the converter (2.7) increases relative to that delivered to the idle state if the joystick is tilted to the right and decreases if it is tilted to the left.

Similarly the value (2.10) delivered by the converter (2.8) increases if the handle is tilted backwards and decreases if it is bent forward. The value indicative of the state of the stick at rest is not zero.

 - The values (2.9) and (2.10j can be recorded in buffers (2.11 and 2.12) controlled by an external switch (2 17) .The user will have to operate this switch when the joystick is at rest so that the The values recorded in buffers bufX and bufY correspond to the signal delivered by the stick at rest, and the values maintained in (2.11) and (2.12) are (2.13) and (2.14) it is of course inadvisable to modify the sensitivity of the device. as soon as the idle state has been registered since the value of the idle state may no longer correspond to (2.13) and (2.14) It is noted that the values (2.13) and (2.14) could have been pre-recorded in the case the device would be inseparable from the device to which it is connected.

- Two subtractors (2.15) and (2.16) perform the operations
(2.19) = (2.9) - (2.13)
(t) (2.18) (2.10) - (2.14)
The values (2.19) and (2.18) correspond respectively to the bytes X7..X0 and Y7..Yc) which will be outputted from the device. These are two signed bytes. We can predict that if the mathematical values (2.19) and (2.18) exceed the bounds of a signed byte [-128 .. + 1271, they will take the value of the nearest terminal.

 - The values (2.19) and (2.18) with the state of the buttons (2.26) and (2.27) can be put in the form of three bytes (see above) by judiciously arranging the corresponding lines (device 2.21) The corresponding values additional buttons can not be used in this case.

 - The values (2.26) and (2.27) are maintained in the buffers (2.28) and (2.29). There is recording when the device emits data, that is to say the signal (2.22) of (2.20).

- A combination of logic gates (2.20) makes it possible to see if the value of (2 19) and (2.18) are non-zero or if the state of one of the buttons has changed since the last data transmission (c ' ie if (2.30) ez (2.26) or (2.31) <> (2.27)). In this case the data can be issued; The transmission authorization is transmitted by the signal (2.22) at a frequency dependent on the clock (2.32)
- If the data can be transmitted (that is, when the signal 2.22 indicates it), each byte (2.23) is serialized in turn by the module (2.24), as was said earlier.

The serial data (2.25) is redirected to the output. The state of the buttons is also saved in the corresponding buffers

Claims (6)

 1) Device for connecting a pointing device to a computer, replacing the mouse, characterized by the fact that it accepts as input signals characteristic of a position, that it converts them into characteristic values of a move, and because it emits these transformed data after putting them in a specific format simulating the operation of the replaced mouse. 2) Device according to claim 1 characterized in that the transformation consists of subtracting  the characteristic value of a position a characteristic value of the rest position (also called stable or origin or initial), in that the result of this subtraction is multiplied by a coefficient (positive or negative), in that the result of this multiplication is added a constant, and in that the result of these operations can be obtained by any electronic means (programmed or not) as long as the result is the expected one. 3) Device according to claim 1 or claim 2 characterized in that the characteristic signals of a position accepted input are of analog nature and are transformed into digital data. 4) Device according to any one of the preceding claims characterized in that in addition to characteristic data of a position, the device acquires its input signals characterizing the state of buttons. 5) Device according to any one of the preceding claims characterized in that it formats the data it has in a format specific to the type of mouse whose operation is simulated, and emet these data formatted periodically , but does not issue if these data are for a zero value part and for another part have not changed since the last issue. 6) Device according to any one of the preceding claims characterized in that it draws its power supply in its connection with the computer to which it is connected and an additional power source if the first is considered insufficient.