The Wistone Project: Sensors embedded in roads in order to keep track of maintenance. Our Project: Wireless access and control of the sensors via a 433MHz/2.4GHz transceiver implementing an API over MiWi- a Microchip software stack. Also, a CLI implementation to be used via PC to connect wirelessly for control and data communications.
Figure: General scheme of the Wisdom Stone project. A PC connected to a communication plug, wirelessly communicating with a wisdom stone embedded in the road.
Currently, the stone supports only one sampler – an accelerometer that is used in many systems such as Smartphones, and is known for its low cost and low power consumption.
Initial work included assisting the project supervisor in choosing the different hardware components and development environment. This resulted in the selection of Microchip’s Explorer 16 Dev Boards, a PIC24 microcontroller and the MRF49XA transceiver for sub-GHz frequencies. Additionally, the MiWi software stack for networking was also selected as the basis for the networking layer.
As the WiStone is to be embedded in roads, the 433MHz frequency was selected, under the assumption this radio frequency will penetrate the road surface better. Another result of using a small low frequency transceiver is low power usage, which is a very important element of the final product.
After work was wrapped up on the networking layer we helped in supporting USB communications with a PC; writing and testing a driver for the first accelerometer on the system; and general integration with the other parts of the system’s elements and code.