Check the listing for details. Freescale TWR-K21D50M 32-bit ARM MCU, New open-box. Condition: New – Open box. Listed at 159.95 USD. The TWR-K21D50M module is a development board for the Kinetis® K11, K12, K21 and K22 MCUs, which are ideal for optimized, cost-sensitive security applications. This Tower® module is designed to enable rapid prototyping and development for applications requiring medium embedded memory densities, security through tamper detect and crypto unit and communication through USB. The TWR-K21D50M module operates as a standalone debug tool and can also be combined and used as part of the modular Tower System development platform. Includes supporting cables & new coin battery Microcontroller MK21D MCU: MK21DN512AVMC5 or MK21D512VMC5 in a 121 MAPBGA Connectivity Standalone USB 2.0 on-the-go (full speed) Tower connectivity for access to UART, SPI, I²C Debug Integrated, open source JTAG Sensors MMA8451Q 3-axis accelerometer Tamper pin header Tower® Plug-In (TWRPI) Components Potentiometer 4 LEDs Pushbuttons Nd battery holder