Day 3 July 8th- Team projects get underway

Chris:

When you begin figuring out where to purchase materials for your project, there are four highly recommended websites to start with. The first is Amazon, where we buy a large portion of our supplies; MIT has special accounts that ensure fast, discounted shipping compared to the general public. For physical materials like metal, wood, and motors, Grainger and McMaster-Carr are excellent choices, with the latter being a favorite among MIT engineers. Finally, if your project requires electronic components, Digi-Key is the ideal place to look.

If you find yourself struggling with the next steps of your project, conducting a simple online search can provide invaluable guidance. Try typing a brief, five- to eight-word description of your project into Google, followed by the word "DIY." Because few ideas are entirely unprecedented, you will likely find videos or tutorials from people who have built something similar. While you should not simply copy their work, you can use their solutions—such as specific circuit designs—as a starting point to help guide your own project's direction.

As our workspace is becoming increasingly crowded, it is important to claim a designated area while remaining mindful of those around you. We have extra tables in the back, and you are welcome to move up to the front to work. On days when there are no conflicting programs, we might even expand into the hallway or the classroom across the hall. Try to find a space to call your own, but remember to spread out politely and avoid crowding your peers out of their work areas.

Later this week, you will participate in mid-design reviews, giving you the opportunity to pitch your idea to MIT professionals who have not yet seen your work. These sessions, which will likely take place on Thursday or Friday, serve a dual purpose. First, they allow you to practice presenting your concepts clearly and concisely. Second, explaining the technical aspects of your design to fresh eyes will likely prompt insightful questions that you have not yet considered, providing you with 15 minutes of valuable feedback.

Throughout the summer, you will receive a vast amount of advice from various people, but it is ultimately up to you to filter and apply it. You should listen respectfully to everyone's input. However, you must decide for yourself which suggestions are actually right for your project, rather than blindly following someone just because they insist their way is the only correct way to do it.

Visitors from Turkey:

Animal Prosthetics:

Rocket delivery:

  Discussion centered around design of a landing system, with both steering and landing gear.

Designing landing gear:

Star Glasses:

 

It was suggested to combine this with Google Sky Map

Radio System:

Team wants to combine analog radio transmitter with a digital message.

Prof Jim Bales consulted with the team on the design of analog radio communications:

https://www.circuitbasics.com/amplitude-modulated-transmitters/

Method 1: Build a Microcontroller Walkie-Talkie (Recommended)

This is the most beginner-friendly approach because it uses pre-certified radio modules. Using an RF module means you do not need an amateur radio license to start testing. []

Components Needed (Per Unit):

1 x Arduino Nano or ESP32 microcontroller
1 x nRF24L01 or ESP-NOW Wi-Fi transceiver module
1 x Electret microphone module
1 x Speaker (8-ohm, 0.5-watt) and a small audio amplifier (like the PAM8302)
1 x Push-button (to act as the "Push-to-Talk" switch)
1 x Breadboard and jumper wires (for prototyping)
1 x 9V or 3.7V Li-ion battery [1, 2, 3, 4, 5, 6]

How to Assemble It:

Power & Ground: Connect the 3.3V output of your Arduino or ESP32 to the transceiver module. Place a 470 μF capacitor across the power lines to filter voltage spikes and stabilize power. [1]
Audio Input: Connect the microphone module's output to an analog pin (e.g., A0) on the microcontroller. [1]
Audio Output: Connect the speaker to your audio amplifier, and connect the amplifier to a digital/DAC pin on the microcontroller. [1, 2]
Push-to-Talk (PTT): Wire the push-button to a digital pin and ground. This button will tell the microcontroller when to switch from "listening" to "broadcasting". [1, 2, 3, 4]
Program: Upload a simple transceiver script using the Arduino IDE. Libraries like RF24Audio for Arduinos or ESP-NOW for ESP32s handle the heavy lifting of audio data transfer. [1, 2, 3]

Method 2: The Analog / RF Approach

If you want to build the physical radio from fundamental components (without digital code), you will need basic soldering and RF electronics knowledge.

Components Needed (Per Unit):

Transistors (like BF494 for the modulator and 2N3866 for amplification)
Variable capacitor (1 pF to 40 pF) and an inductor to tune to your target frequency (e.g., 27 MHz or an FM band frequency)
Electret microphone and an Op-Amp (like the LM386) for audio
12-ohm speaker
RF Antenna [1, 2, 3]

How to Assemble It:

The Transmitter: Solder your microphone to the audio amplifier circuit. Connect that output to a transistor oscillator circuit to convert your voice into a high-frequency radio wave. [1, 2]
Tuning: Use a variable inductor or variable capacitor to align the frequency of your circuit to the desired band. [1]
The Receiver: Build an AM/FM receiver circuit (a mixer IC like the SA612AN is very popular for this) to extract the electrical audio signal from the airwaves. [1, 2]
Finally, feed that extracted signal into an Op-Amp and directly to your speaker. [1]

Grab and Go System:

     Discussed practicality of a drone-based retrieval system, due to limited lifting capabilities of consumer drones, difficulty of grabbing items, and navigation. I suggested starting with a warehouse-type robot that collects selected items from motorized spiral dispensers into a cart. They said the most important part of the project to them is the claw mechanism, which they want to build themselves; the do not want to buy a claw kit.