Mikroe Smoke 2 Click features the Analog Devices ADPD188BI complete photometric system for smoke detection using optical dual-wavelength technology. The module combines the dual photodetector with two separate LEDs and a mixed-signal photometric front-end ASIC. It’s housed in a package that prevents light from going directly from the LED to the photodiode, without first entering the smoke detection chamber. It supports an SPI and I2C serial interface, although only one is allowed at any given time in the actual application.