Oscar has written an article describing a technique he’s used for reading multiple analog sensors with one MCU ADC pin. He was designing a line-following robot and wanted to read several infrared sensors without having to dedicate an analog read pin for each. His solution uses “a Schmitt trigger inverter whose output has resistors connected in a series of different values attached to a common point. From this point the voltage value is measured, which will be different depending on the active sensor, being able to know the position of the robot.”
You can find the complete explanation of Oscar’s project on his website. Note that this is a multi-lingual post.
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