At the heart of the eZ430 Chronos is a CC430 wireless MCU, specifically CC430F6137. This is an MSP430-based microcontroller with an integrated sub-1 GHz RF transceiver. This kit is available in three different frequency bands: 433, 868 and 915 MHz. These frequency ranges (sub-1 GHz) allow for longer range of system communication and less susceptibility to interference from objects like walls, people, water or microwaves. Disassembling the eZ430 Chronos allows the user access to the two-wire JTAG interface on the CC430. The CC430 controls the whole system. This includes driving the 96-segment LCD, which is a numerical display (so it is limited as some alphanumeric characters can not be displayed), but can do some text and the icons that are built into the watch. Additionally, it has a buzzing capability which can be programmed as an alarm or activated via pushbutton when the watch is fully assembled. This development kit incorporates several different sensors: a three axis accelerometer, a pressure and altitude sensor, a temperature sensor and a voltage sensor typically used to monitor the CR2032 battery that powers the eZ430 Chronos. Included with the development kit is the eZ430 programmer for in system programming. An RF access point is provided as well for wireless data transfer. This allows the user to transmit new firmware images directly to the watch. Finally, a disassembly tool is provided to easily take it apart.