Disassembling the Mouse

lehuijie

Disassembling the Mouse [Copy link]

 I disassembled a mouse that I have been using for more than two years. The USB head had an electrical problem and often failed. I will see if I can post a rescue post one day. Now let's get to the point. This is the body after disassembly.

The body of the mouse

The light source of the mouse is a red LED light. Compared with ordinary LEDs, the light beam of the small light is relatively concentrated. This is related to the work of the mouse.

Mouse light source

The convex lens below is used to make the light more concentrated. The light emitted by the light source is magnified and then passes through the convex lens, reflected on the mouse pad, and the reflected light passes through another convex lens. When the mouse moves, the reflected light source will change. The light source signal is obtained and processed according to the light source detection device of the mouse, and finally the mouse movement data is output according to the HID protocol. This working condition is guessed based on the device and cannot be used as a professional reference.

Convex lens

Optical signal processing chip

Of course, the mouse should also have buttons and a scroll wheel. The buttons should be so crisp when pressed and not in use, and some of the rebound force should be provided by the shell.

In addition, I would like to give you aUSB mouse communication format (this isvonly’s blogreprinted) for your reference. The data that the mouse sends to the PC is 4 bytes at a time: BYTE1 BYTE2 BYTE3 BYTE4. The definitions are: BYTE1 -- |--bit7: 1 Indicates that the change in the Y coordinate exceeds the range of -256~255, 0Indicates that there is no overflow |--bit6: 1 Indicates that X |--bit5: the sign bit of Y coordinate change, 1 indicates a negative number, that is, the mouse moves down |--bit4: the sign bit of X coordinate change, 1 indicates a negative number, that is, the mouse moves to the left |--bit3: Always1 |--bit2: 1Indicates the middle button is pressed |--bit1: 1Indicates the right button is pressed |--bit0: 1Indicates the left button is pressed BYTE2 -- the change in the X coordinate, combined with bit4 of the byte to form a 9-bit signed number. A negative number indicates a left shift, and a positive number indicates a right shift. Use the complement code to express the change amount BYTE3 -- The change amount of the Y coordinate, and the bit5 of the byte form a 9-bit signed number. Negative numbers indicate downward movement, and positive numbers indicate upward movement. Use the complement code to express the change amount BYTE4 -- The change of the scroll wheel.