Pre-Existing System
We are upgrading a sytem that is already in place with wireless research capabilities. The current system collects data with a seismic sensor called a geophone. The data from the sensor goes into a microprocessor which put it into data packets. This system is designed to work with no configuration.
The Benefit
The data is stored on SD cards, and it has to be individually collected from every sensor unit. This means there is a delay between the time the data is recorded and when it is viewed. The wireless upgrade would allow the data to be accessed in real time; the data can be viewed when at the same time it is recorded.
Overall System Description:
The diagram shows the different steps in our system. First, the field unit collects data. Then, the transmitter sends the data to the reciever. The reciever picks up the radio waves from the transmitter. The central database, the computer in this case, gets the data from the reciever so that it can be viewed.
The Radio
The radio is the SiFLEX02. It is a 900-928 MHz spread spectrum radio. It is designed for low power applications, which makes it ideal for this system.
The Projects
Serial Communication
Using the development kit for the SiFLEX02, communication between the radio and a computer has been achieved. The code, written in Python, commicates with the radio using serial packets. By configuring the radios, they can communicate with each other. Modifying this code to be in embedded C, it could be implemented on the actual system
MATLAB Code
The purose of the MATLAB program is to simulate endcoding, and signal transmission.
This program first simulates encoding and transmission of the data. Next, noise is introduced into the data in order to simulate free space losses. Finally, the recieving is simulated and the data is decoded.
PCB Layout
The PCB, printed circuit board, physically connects the radio to the existing board. The schematic for the PCB has been completed.