The goal of this project was to network the plants of our ECE Dept. roof garden and monitor humidity and temperature for efficient watering (and water supply management). Additionaly, we wanted to monitor the number of cars entering (or leaving) the parking area below the garden and convey such information, through our custom, wireless, multi-hop, energy-aware sensor network!
The project was part of lab work, in the context of "TEL404 - Analysis and Design (Synthesis) of Telecom Modules", offered in the 8th semester of Electronic and Computer Engineering Dept., at Technical University of Crete and taught by Assist. Prof. Aggelos Bletsas.
TEL404 provides a critical bridge between telecom theory and practice and assists students to imagine, design, realize, test and improve end-2-end telecom systems/networks. More importantly, teaches students to be bold and adventurous enough to implement (rather than just reflect upon) their ideas.
The theoretical modules of the course include basic receiver architectures (heterodyne, superheterodyne, homodyne, image reject and digital IF recs) [Signal and Systems prerequisite]. Then, they learn to read and understand basic specification quantities related to intermodulation products (IP3) and noise figure (NF) ; they learn to read specs of individual systems (e.g. LNA, PA, Filter) and calculate end-2-end system IP3 and NF [Electronics I prerequisite]. They learn basic microwave engineering (VSWR, Smith Chart and matching) [Electrical Circuits I and II prerequisites]. They also learn the fundamental tradeoffs of resonant systems. Finally, they learn to identify at the circuit level (and not just at the block level) all internal systems of a super-het receiver.
Laboratory work includes learning how to setup a wireless, digital link with programmable, embedded, low-cost, low power, 2.4GHz transceivers, with controllable modulation, transmission power, error correction and baud rate [Telecom Systems I and II]. Programming the low-cost, custom-made transceivers (assembled by the course instructor - "iCubes" v0.1 at the picture above) is realized through an 8051 MCU and code in wonderful, plain, old-fashioned C [Programming I and Embedded Systems prerequisite].
Then, they learn how to interface sensors to ADCs and computers (and also learn the fundamental tradeoffs). Finally, they learn how to design printed circuit boards (PCBs) with professional CAM software, paying attention to basic EMC/EMI rules. Students are asked to design a board, which eventually is sent out for manufacturing [yes, we did that this year!].
That was the first year TEL404 was offered. Much work is left to be done. Hopefully, additional modules next year will include RFIDs and USRPs. It is unquestionable that with such enthusiastic and hard-working students, as those participated this year, the class will continue to be great fun!
The course instructor would like to thank Lab assistant S. Andrianakis for all his valuable help, as well as all members of Telecom Lab.: Prof. Karystinos, Prof. Liavas and Prof. Sidiropoulos for financially supporting the procurements of required equipment and endorsing the idea behind a "telecom synthesis lab course".