Project

# Title Team Members TA Documents Sponsor
51 Easy Bake PCB's
 Bhaven Shah
Raghav Narasimhan
Zak Kaminski
 Prannoy Kathiresan design_document3.pdf
final_paper1.pdf
photo1.jpg
photo2.jpg
presentation1.pptx
proposal3.pdf
video
# Easy Bake PCB's

Team Members:
- Bhaven Shah (bhaven2)
- Zak Kaminski (zak5)
- Raghav Narasimhan (rnn3)

# Problem

Often for my RSO, Illini Solar Car, we have to hand solder very small SMD components such as 0603 or even 0402 imperial codes. This often leads to failures on our boards as solder joints fail causing the entire board to short. This negatively affects our team’s performance during our races as we then have to repair the car by finding the source of the issue and then replacing that board. This costs us valuable time in our race as we want to be driving every possible second we are allowed to keep us competitive. Soldering is also a skilled activity, meaning many hours are required to become proficient. These are hours students are losing to work on other projects or school work. Having a reflow oven would save many hours of labor which can be used for design reviews or designing new PCBs.

# Solution

Our solution is to build a custom reflow oven by converting a toaster oven. While this is an item that you can commercially purchase off the shelf, it is not something that our team can fully justify the cost of as good reflow ovens can cost north of $300 USD. Also there are a couple of commercially available products that you can purchase to modify your toaster oven, but they are never in stock to purchase. As there is a parts shortage, we will have to design our own conversion kit that can be built with readily available components. Our reflow oven will also include an alert system that utilizes video to determine if a component has slid out of place. This is something that current commercially available reflow ovens do not include and will be cheap enough that even enthusiasts could build one themselves.


# Solution Components

## Subsystem 1 - Thermocouple:
https://www.adafruit.com/product/269
https://www.digikey.com/en/products/base-product/maxim-integrated/175/MAX31855/82847
The thermocouple system will be used to continually monitor the temperature inside of the toaster oven. Temperature is critical when soldering and ensuring that you have the right temperature will provide excellent results as the Joint Electron Device Engineering Council (JEDEC) Solid State Technology Association has published documentation on “profiles” for reflow soldering that require precise temperatures.

## Subsystem 2 - Camera:
The camera subsystem will be added to constantly monitor the reflow process. It will be a check that ensures that no components are moving during the process causing bad joints to be formed and will immediately stop if it detects that a component has moved too far from its original position.

## Subsystem 3 - Heating & Fan Control:
It is extremely important to use a heating device that produces precise changes in temperature and responds quickly to desired changes in temperature. The fan is also important to not allow the components to overheat.

## Subsystem 4 - Touchscreen:
Used for easy user interaction with the reflow oven in order to set the user’s desired temperature and duration as well as to give visual feedback to the user.

## Subsystem 5 - Power Supply:
Wall outlet and will be converted to the desired range for the on-system chips.

## Subsystem 6 - Microcontroller:
Will take in the temperature and camera data to determine when to turn on or off the fans, when to increase or decrease the temperature in the reflow oven, and alert when the components move in an undesirable fashion. It will also control the touchscreen.


# Criterion For Success
* Reflow solder PCBs with 10% margin of error
* Detect when a component covers less than 70% of the pad and alert the user (further testing required to determine how far a component is allowed to move and still be viable)

Wireless IntraNetwork

Daniel Gardner, Jeeth Suresh

Wireless IntraNetwork

Featured Project

There is a drastic lack of networking infrastructure in unstable or remote areas, where businesses don’t think they can reliably recoup the large initial cost of construction. Our goal is to bring the internet to these areas. We will use a network of extremely affordable (<$20, made possible by IoT technology) solar-powered nodes that communicate via Wi-Fi with one another and personal devices, donated through organizations such as OLPC, creating an intranet. Each node covers an area approximately 600-800ft in every direction with 4MB/s access and 16GB of cached data, saving valuable bandwidth. Internal communication applications will be provided, minimizing expensive and slow global internet connections. Several solutions exist, but all have failed due to costs of over $200/node or the lack of networking capability.

To connect to the internet at large, a more powerful “server” may be added. This server hooks into the network like other nodes, but contains a cellular connection to connect to the global internet. Any device on the network will be able to access the web via the server’s connection, effectively spreading the cost of a single cellular data plan (which is too expensive for individuals in rural areas). The server also contains a continually-updated several-terabyte cache of educational data and programs, such as Wikipedia and Project Gutenberg. This data gives students and educators high-speed access to resources. Working in harmony, these two components foster economic growth and education, while significantly reducing the costs of adding future infrastructure.