Nova Fitness SDS011

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1

one year working Nova Fitness SDS011 sensor with a rusty metal cover

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2

desolder the + and - terminals for the diode on the top right corner

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3

remove screws showing the photocell (rectangular on the right)

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4

close on the photocell. The cell is connected to the circuit board on the back. On the right showing the terminal for the laser diode.

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5

remove the fan from the top cover. Look pretty clean inside.

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6

looking for accumulated dust but did not found much

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7

found dust on the baffle where the air is coming in and on the wall before pulling out by the fan

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8

close on the where the dust was accumulated

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9

This is where the magic started to happen. The laser diode pulses light across the airflow path and somehow, PM2.5 concentration is estimated by a photocell placing on the ceiling

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10

remove the metal cover and looking for the brain of the sensor

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11

STMicroelectronics NUCLEO-F031K6 chip

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12

Under the cover with the main IC, and TI 77 as the op-amp