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alexaverificationtools

biot_savart

This project was to explore Biot Savart's law that relates the magnetic field along an axis through a solenoid. I built a test probe using a hall effect sensor that moves along the axis with exact precision using a stepper motor. The stepper motor is controlled by a circuit I built on a custom PCB. I chemically etched the PCB using negative photoresist, developer, and chemical etchant. The Hall effect sensor is amplified with an opamp and connect to an analog to digital converter(ADC). The ADC sends magnetic field strengh data to a raspberry pi. The sensor is driven along the axis and samples measurements at timed interval. The variable in the system is a change in current applied to the coil. It is observed that the magnetic field is non-linear at a certain point due to the inheritant resistance of the copper wire and the max. densitity of magnetic lines of flux in an air core.

blackwidowfreertos

Embedded RTOS code for stepper controller

camera_slider

Camera Slider project using python to control two stepper motors with a user interface that includes a small oled screen and three buttons. Several challenges arose for this project. The primary challenge is portability. As an astrophotgrapher, I require the camera slider to be portable. The challenge with this is two stepper motors pull a lot of current. To deliver this current, I created a 3D print that would repurpose the lithium batteries used on my portable hand drill. The drill has 20V output and can deliver current on an order of 1-2A per hour. The second challenge was torque. I needed my camera, 5lbs, to be able to move in a vertical direction. Most commercial camera sliders cannot move at this steep of an angle. The second problem was the H-bridge stepper driver. I used an L293D H-bridge driver which turns out to have a low continuous current spec. As a result, the chip get's extremely hot. I designed my PCB utilizing a DIP chip in order to facilitate fast replacment. I also use a large heat sink to manage the heat. Another problem with the camera slider is the elements. My timelapses often take me to extreme altitudes and the preciptation tends to cause my camera lens to fog up. I use the heat created from the IC chip to defog the lens. I do this by moving air into the control module, over the chip, and exhaust it with a fan, through a hose, and onto the camera lens.

cse373

Advanced Data Structures

ee371_lab1

This is my revision control repository for EE 371 (Digital Circuits)

greenhouseautomation

Green House Automation Project

images

Images for hosting

lambdaservice

AWS Lambda functions for Alexa Skill (Flash Card Service) and Scheduler.

pcbdesign

To manage my PCB Design files across multiple computers.

pycontroller

Generic interface between game controller and user controlled objects such as motors, actuators, LED's, etc.

test_repo_pylinter_v1

Demo repo to accompany YouTube video demonstrating how to use the pylinter GitHub action