The MikroElektronika Fan 3 click is the perfect choice for fan speed control and it can operate in seven discrete speed steps. Unlike the PWM regulation which can sometimes cause the infamous coil whining effect on some types of fans, this click board outputs the selected voltage via the MIC29152 voltage regulator from Microchip, driven through the MIC74 - a serial to parallel I/O expander and a fan controller from the same company, keeping it constant at the output. Type Brushless
Interface I2C