After purchase, reply to your order confirmation email to request a free FRDM-MCXE31B, FRDM-MCXN236, FRDM-MCXA153, or FRDM-MCXA156 coupon to evaluate MCX microcontrollers. The FRDM-K66F is a low-cost development platform for Kinetis K66, K65, and K26 MCUs. * Audio features such as audio codec, digital MEMS microphone, auxiliary audio input jack, headset/analog microphone jack and two inputs for additional analog microphones * Peripherals enable rapid prototyping, including a 6-axis digital accelerometer and magnetometer to create full eCompass capabilities, dual role high-speed USB interface with Micro-B USB connector, a microSD card slot, and connectivity using onboard Ethernet port and headers for use with Bluetooth® and 2.4 GHz radio add-on modules * OpenSDA v2.1, the NXP open source hardware embedded serial and debug adapter running an open source bootloader, offers options for serial communication, flash programming, and run-control debugging * Fully supported in the Arm® Mbed™ platform, with access to free tools and SDK