An Introduction to TinyOS and the Mica2 Programming EnvironmentBrent RoodDepartment of Computer ScienceSUNY [email protected] the proliferation and ever growing popularity of sensor networks in the Computer Science community recently, it has become a topic of study for many graduates and undergraduates alike. However, even with this sudden growth, there is still a large barrier that must be crossed in order to first start programming and utilizing the motes. It is the purpose of this paper to introduce the key concepts involved with programming motes as well as a decent knowledge base covering the basic aspects of the tools used.First, I present the basics involved in the use of motes. This includes their characteristics, physical attributes and methods which can be employed to program them. Next, Iwill discuss the overall TinyOS environment andthe features that it provides. Furthermore, TinyOS employs a powerful modular programming language called NesC, thus it is necessary to touch on this aspect. It is also necessary to discuss the TOSSIM simulation environment which can be extremely useful when debugging TinyOS applications. There are also other features included in the TinyOS distribution which certainly bear mentioning (e.g. TinyViz). Next, I explain my implementation of two routing protocols that I’ve developed in TinyOS and uploaded/tested on mica2 mote hardware. I examine the characteristics of these routing protocols and alsodiscuss the positive and negative aspects that both of these protocols bring to sensor networks.1. IntroductionAs sensor networks gain popularity with the computer science research base, it becomes increasingly necessary for a basic tutorial to overview the basics involved in the use of the tools used for sensor network development and deployment. While there exists a lot of work on this subject in general, it can be said that no paper completely summarizes all the informationnecessary for one to start from scratch, so to speak, and to be able to learn all the necessary aspects and skills needed to utilize motes. The resources containing the information are quite disparate and putting all the pieces of the puzzle together can be quite daunting for the beginner (as it was for me initially).However, the applicability of this pursuit can be called into question. While it is true that sensor networks have yet to have found their “killer app”, it is quite obvious that there are many applications in which sensor networks will thrive, thus making them an interesting research field. Sensor networks can see deployment in battle field scenarios, monitoring enemy movement in order to warn friendly troops of the enemy’s activity. Also, on the flip side of the coin they can be used to track friendlymovement in order to avoid friendly fire. However, the applications are not limited to military uses. Scientists have used sensor networks for a variety of sensing needs from detecting the nesting habits of birds [7] to monitoring the temperature at various levels of a forest. It is clear that sensor networks have a wide range of purposes and as technology grows,it will become more and more feasible to deploy them in various scenarios. As a direct result of these applicability scenarios, it is quite obvious that interest in sensor networks, and as a direct result, research in the sensor network will only grow.For these reasons, this paper pursues giving a “crash course” in sensor networks through the use of an overview of the various aspects initially, followed by direct examples including two separate implementations. The implementations are present to give the reader a concrete example of the steps required to bring a 1sensor network concept from idea to reality. They also serve another role in exemplifying certain concepts that are key to the development of sensor networks. One of these main concepts is energy expenditure which is always a prevalent design concept when discussing sensornetworks. This will be discussed later in the paper.2. Mica2 Mote HardwareThe first aspect that must be discussed in detail is the actual hardware being worked on. Currently, there are many different mote platforms that one can develop on. However, there is one designer that stands out from the crowd. The people at Crossbow have been producing quality sensor network platforms since around 1995. Throughout this time, Crossbow has seen the hardware on these sensors become increasing powerful and useful. Sensors themselves have continually evolved as manufacturing processes become more efficient, also allowing the price of these individual sensors to decrease.Currently, Crossbow offers a variety of sensors at the disposal of users ranging from industrial companies looking to keep tabs on their running equipment to researches looking to use the motes as a development platform. However, the simple matter of the fact is that Crossbow does not offer support in the arena of developing new software for use on its motes. It comes with the current implementation of TinyOS and a number of example applications that can be uploaded onto the motes they manufacture. However, if one attempts to contactCrossbow for developmental support (as I’ve found out), the manufacturer’s of the motes will offer little to no guidance. They claim that TinyOS is a separate arena and not their responsibility. Thus, research into the development of new applications for running on this mote hardware must be done independently.However, once one gets past this lack ofsupport, Crossbow does have a lot to offer [9]. For the purposes of this paper, we will only cover the motes intended for research and skip over the motes specifically designed for use in specific industrial applications. In this venue, wehave several options. One of the newest is the TelosB mote, which has better specifications than previous models in terms of bandwidth, processing power and lower energy usage. However, this paper focuses on the previous generation of mote referred to as the Mica2. The Mica2 is Crossbows third generation of sensor mote (previously, the micaDOT series) and carries with it certain advantages over earlier models. The Mica2 boasts [3]:433, 868/916, or 310 MHz Multi-Channel Radio Transceiver128 Kb program flash memory512 Kb serial flash18 grams total weight2 AA batteries for powerThe important characteristics to take away from this are the overall small size and weight of the device