The SparkFun Photodetector Breakout is an updated version of the SparkFun Particle Sensor Breakout includes the MAX30101, a highly sensitive optical sensor and successor to the MAX30105 and MAX30102. The MAX30101 Breakout utilizes a photon detector to measure the amount of returning light that is reflected back from the LEDs. This is useful for various applications like particle (i.e. smoke) detection, proximity measurements, and even photoplethysmography. To make it even easier to use this breakout, all communication is enacted exclusively via I2C, utilizing our handy Qwiic system. However, we still have broken out 0.1" spaced pins in case you prefer to use a breadboard.