| 摘要 |
A light intensity sensor includes photodiode or other light sensitive device, and a capacitor connected to the photodiode. A microcontroller measures the time interval required for the capacitor to reach a predetermined voltage level. The current produced by the photodiode as a function of the light intensity is known, such that the time interval can be used to determine the light intensity. The microcontroller is configured to reset the capacitor voltage to zero after the predetermined voltage level is reached, and the measuring process is repeated.
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