| 摘要 |
A variable resistance measuring loop having compensation function for environmental factor is disclosed. The measuring loop comprises a central processing unit CPU connected by one end of the variable resistance to the PO.1 leg thereof, and the other end being connected to the PO.2 leg thereof, the center end thereof being connected to a drain of a charging switch transistor Q, the base of the transistor Q being connected in series with a resistance R to the PO.3 leg of the CPU, the emitter of the transistor Q being connected to VDD power source end, the drain being conductive with the PO.0 leg and being connected in series with a charging/discharging capacitor C to a common ground, characterized in that the two ends of the variable resistance is connected to a control loop which is connected to a capacitor charging/discharging and the amount of movement is calculated via a discharging formula, and due to the two ends of the variable resistance is connected, the measuring loop is not affected by environment factors in the mouse cursor controller circuit.
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