mituldesai_andrew_bollin

1. WirelessWeatherStation By: Andrew J. Bollin EET, Mitul B. Desai EET Mentor: Xuefu Zhou, Ph.D. College of Engineering & Applied Science University of Cincinnati Budget The budget shown in table # 1 is a complete breakdown of our expenditures needed to complete this project. This budget does not include man hours or research and development costs. Design Requirements The major design objectives that were considered fell under two main categories. The first being hardware; what hardware components do we want to include and what attributes of the weather are we interested in. The second category is software. The objectives we have come up with are wind speed and direction, temperature, humidity, barometric pressure, and ambient light are the sensors that are included. The data is then sent wirelessly to a computer where the collected data is then displayed. Technical Approach The backbone of the weather monitoring unit is the BasicAtomNano 28 microcontroller, it acquires data from the six weather sensors and then sends them to the XBee wireless modem. A second XBee modem is connect to a computer and creates a wireless serial connection with the weather monitoring unit’s XBee modem, over which the data that was collected is sent. This data is then picked up by the graphical user interface which is used to display the most current data and provide an intuitive display of the collected data. The flow chart in figure 1 is a visual representation of how the hardware and software interface with each other. Abstract The weather is constantly changing as many of us have experienced with snow one week and a high temperature in the 80’s the next. How many times have you have woken up in the morning uncertain of what to wear? Maybe a last minute decision is needed to bring a jacket or shed that extra layer. Having weather conditions at your finger tips would help eliminate these problems. This is where you would benefit from our Wireless Weather Station. The station is comprised of sensors that detect barometric pressure, ambient light, humidity, temperature, wind speed and direction. This data is then processed by a microcontroller and relayed to a PC via a wireless connection. The PC can then display the data using a custom Graphical User Interface (GUI). This will give a visual representation of conditions and help make an informed decision. Introduction This wireless, self contained system can be place nearly anywhere accurate weather measurements are needed, and the only additional equipment that is needed is a computer to view the live measurements that are feed to a program. The ease of use and simple interface makes this system a very user friendly device. The limitations of the system are dependent on the sensors that are used. The distance that this system is capable of working depends on the XBee component installed, and can be easy switched out allowing for a longer operating distance. The battery life of the system is limited to the number of charging cycles that the battery can handle. Like the wireless interface, the battery can be changed out for a newer or even larger capacity unit, making this system customizable for the consumers needs. Table #1: Budge Figure 2 shown above, is the schematic of the weather monitoring unit’s printed circuit board. This circuit shows all of the connections that are needed to have a working system. On the final PCB the all of the sensors are going to connected using sockets which will allow easy maintenance if a sensor were to go bad. Below are pictures of the components, and sensors used. Figure 2: Schematic Project Results The final product performance is that of what was described in the project design specification. The weather monitoring unit is self-contained with a battery and solar power source. The XBee wireless modem that is being use will provide up to 120 meter of range and still allow the unit to run for 36 hours on battery alone. Some future improvements that could be pursued include a wireless LCD monitor that will display the incoming data without the need of a computer. If the wireless modem is switched out for a more power full model the working range could be drastically increased into the mile range. Other improvements could be made to the graphical user interface to include an RSS feed to down load weather forecasts, allowing the user to see past, present, and future weather conditions. Barometric Pressure Sensor(1), Wind Speed & Direction Sensor(2), Humidity Sensor(3), Temperature Sensor(4), XBee Modem(5), Ambient Light Sensor (6) 3 1 2 5 4 6 Testing Approach Once the prototyping was complete and a final schematic was produced, the weather monitoring unit was tested by subjecting it to conditions that it would normally face and have to perform under. The wind speed and direction sensors are already weather proof making them easy to test. The other sensors are going to be housed in a weather proof case that will protect them from the very weather they are measuring. Moisture and humidity is the greatest enemy for any kind of electronics. To protect the circuitry that is connected to sensors, a conformal coating will be used to protect the final printed circuit board from moisture, corrosion and thermal shock. Figure 1: Flow Chart