this is a non-functional unit showing 900 ug/m3 readings. The design looks neat, compact and many test points
after removing the plastic cover, here the core of the sensor. The diode was removed. The terminals for the diode is far left on the board
under the metal, the cover is the circuit board which features an STM32F030F4 microprocessor.
close up on the main chip. The circuit looks very nice.
the circuit board with a laser diode with Level 4 printed