Week 25 (Apr. 3, 2019): Current Amplification Solved via Buck Converter

Today, we made the decision of going with the 12V, 600mA induction coil set, as they allowed for a greater distance between the transmitter and receiver, which was a maximum distance of 0.787 inches, as opposed to the 5V, 1500mA induction coil set, which had a maximum charge distance of 0.5 inches.

As a reminder, we are implementing induction charging, also known as wireless charging, to charge the 3.7V Li-ion battery at designated charging stations within the track. This helps to enforce autonomy, which will further eliminate human intervention and manual maintenance of the system.

Because the charge current is smaller, we tried to find a way to increase the charge current used to charge the battery. We settled upon using a buck converter, which decreases voltage with the advantage of increasing current. The buck converter would be placed after the induction receiver and before the battery charger. After some testing, we found that the buck converter could amplify the current to the desired 1A. However, since the battery charger has a maximum charge current of 1A, we decided to lower the charge current to a safer 800mA.

An image of the buck converter is shown below, as well as the Amazon purchase link with all of the product details:

Source: https://www.amazon.com/gp/product/B07JNQFV7F/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1

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Week 30 (May 8, 2019): Prototype Evaluation Day, Final Circuit, Incorporating 3D printed parts, Final Presentation, Posters, & Maker Faire

Today, we held Prototype Evaluation Day. Like the rest of the senior project classes, the advisor walks around the classroom, evaluating the senior project apparatuses, asking the student teams to demonstrate their devices, and explain their design, though processes, and results. Dr. Furman and Ron examined and inspected the Full-Scale model, then the Half-Scale model, and lastly, us, the Small-Scale Team. We had completed our circuit to power one pod car and one of the two induction charging stations prior to Evaluation Day, so we were able to successfully demonstrate the pod car driving around the track as well as the induction charging. While we were still troubleshooting issues with the tablet’s Raspberry Pi communicating with the Arduino, the Arduino is still capable of operating on its own, so we could at least demonstrate the motor driving the pod car around the track and through the offline stations. Depicted below is our final circuit that powers the pod car: Dep...

Week 28 (Apr. 24, 2019): Final motor selection – Mini-Stepper Motor

Since last week, we have been trying to run the new brushless DC motor; however, it is still difficult to control, let alone its speed. Therefore, we had to pursue our alternative motor, the mini-stepper motor that runs at 5V. Found in Arduino starter kits, this mini-stepper motor is accompanied by its dedicated motor driver board, the ULN2003, which is a chip containing a series of Darlington pair transistors. An image of the stepper motor and the ULN2003 board is shown below: Sources: https://www.adafruit.com/product/858 https://www.amazon.com/gp/product/B01CP18J4A/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 We were able to successfully run the new mini-stepper motor with the sample code included with the Arduino starter kit. One benefit to using the sample code is that it utilizes the Stepper library’s functions. One use function is the setSpeed( ) function, which allows the user to set the RPM speed of the stepper motor. We found that the ma...

Week 27 (Apr. 17, 2019): ME 195B - Presentation #2 (Prototyping Stage Continuation) Reflection

Today, we completed Presentation 2, which is our 5 th presentation overall, throughout the entire length of senior project, since last semester. Please refer to our Presentation #2 slides, embedded below. Covering the continuation of our prototyping efforts, we discussed progress on hardware acquisition, integration of components into a working circuit, and programming. Regarding programming, we were still working on the communication between the Raspberry Pi and the Arduino. And while the circuit is also coming together, there was one piece that gave us problems yesterday: the gimbal motor broke and so we had to order another motor that is not a gimbal but is still a brushless DC motor. An image of the new motor is found in our presentation slides below. While this was disheartening at first, we found that the gimbal is not intended for continuous rotation, but instead for precise movement, as they are used for cameras on drones. However, this was still a setback...

Patrick Barrera's Progress for Spartan Superway

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