The Chronos also includes several free software options to help develop a custom application. Several integrated development environments are available including Code Composer Studio from TI and IAR’s embedded workbench. Every compiler that supports the MSP430 can be used to develop code for the Chronos so it is even possible to do projects using the open-source MSPGCC compiler. Since the eZ430-Chronos is a wireless system, a wireless protocol stack is required to communicate with other devices. Several wireless stacks are currently available, and more will be added in the future. Out-of-the-box the Chronos is pre-loaded with both the SimpliciTI (pronounced like simplicity) network stack from TI as well as BM-Innovation’s BlueRobin protocol. These two options enable the user to communicate with a variety of external devices like heart rate monitors or a computer. SimpliciTI is an open-source RF protocol developed by Texas Instruments. It was designed to be an easy to use protocol which only has a few API calls and consumes less than 8KB of flash and 1KB of RAM. It is typically used in a star network topology, meaning that many end devices communicate to a central access point; however end-device to end-device communication is also possible. The BlueRobin protocol is a low-power, proprietary protocol that enables wireless communication with several compatible fitness sensors including certain heart rate monitors and bike cadence and speed sensors. Since the Chronos is based on the CC430, a very popular microcontroller for wireless communication, any wireless protocol which supports the CC430 will also support the Chronos. For example, Wireless M-bus, a common standard used in metering, as well as 6LoWPAN, the wireless standard for transmitting IPv6 packets in personal area networks, and Dash-7, the 433MHz wireless sensor networking technology, are available to run on the Chronos Platform. Several open-source projects are available online that can be used as a starting point or reference. Many projects have already been posted and are available for download at www.ti.com/chronoswiki.