assignment
Propose a final project masterpiece that integrates the range of units covered, answering:
What will it do?
The device is going to generate energy harvesting the electric potencial produced by a piezo-electric device that vibrates with the wind. The simplicity of the system is an advantage, because its parts are affordable and easy to replace if brocken. The energy is going to be used for comunications, specifically to host a LoRa node for IoT.
Who's done what beforehand?
I didn't find something similar in the Fabacademy repo. This work is inspired in the work of Shawn Frayn (even have a Wikipedia page).
However I made a modification in the transducing system. Frayn uses magnets vibrating inside a coil. I am using the piezo-electric device instead. As long as I know, the system is not yet integrated with a service.
What will you design?
I will desing the mechanical system that orientates the collector to the wind. A sensor system based on sound (microphone) will be used to estimate the wind speed, use it, store it, and send it. We use the information from the wind speed to tense the tape system, and adjusting the frecuency of the vibrating part to the wind speed, and capturing a wider range of flows. I am thinking in implement a PID system (used in drones and self balancing robots) to control the precision of the tension force.
What materials and components will be used?
I am planning of using acrilic for the body. The device is going to wistand the elements, so it have to be water-proof. I guess wood could also be used, but then it will need some treatment. I found a bicycle hub (the rotary part from the front wheel), and I am going to use it as a pivot. The sensor part is going to include two electret microphones with a designed amplifier circuit and an Atiny44 chip with a 20Mhz resonator for processing and sending the signal. A board based on the Atmega 328 with a 20Mhz resonator will be used, for better comunication and performance. This device will control a servo motor that will handle the actuation (tension) on the membrane and energy management. The LoRa communications could be handled by a Raspberry Pi, but this part of the project will have to wait. I am not decided yet about the type of battery for strorage, but I guess it will be a standard Lithium or LiPo.
Where will come from?
Most of the materials exist in stock in the lab. I found the bicycle hub in a store nearby.
How much will they cost?
I still need to calculate weights and volumes, but my guess is under 200USD.
What parts and systems will be made?
The sound sensors boards, the main control board and the structure will be made. The bicycle hub, the electronic components, and possibly the Pi will not.
What processes will be used?
2D and 3D design, electronics fabrication and design, communications, laser cutting, 3D printing, possibly molding and casting/composites.
What questions need to be answered?
I think, if more devices like this are installed, we could use the data form the IoT devices to estimate the wind speeds and patterns. I have no aeolic data for this area, but if we make a succeful remote communication we can test it on the field. In the meantime, we have to relly on lab tests.
How will it be evaluated?
The device will be evaluated in the lab, storing the information onboard or in a separate computer. We will measure Voltage, Amperage and total average input (power). In the case of the LoRa part implementation, this information could be available online, even for future colaboration.
