Crucial questions for the semester
#
- If we’re trying to light up an LED with a 5 V supply, why do we need a resistor in series?
- How much power can 5 V drive into a 100 ohm resistor? Could the resistors in your project kit handle that?
- Does a motor get hotter when it’s going fast or slow? Why?
- Can you store more energy in a 100 uF capacitor or in a lithium ion battery of the same volume?
- Why are extension cords rated for a certain voltage and current? How is a cord with higher ratings different?
- Using the stuff in your project kit, devise a few different ways to overload your voltage regulator circuit and tell us which one would dissipate the most power, and why.
- How much energy is there in an AA battery? In a 9V battery? Which has higher energy density by volume, and why?
- Compared to the N-channel set-up, what would you need to do differently to use a P-channel MOSFET to switch your 12-V DC gearmotor on and off?
- What would be the advantages of using the P-channel as a high-side driver instead of a low-side driver?
- How would you select an appropriate motor for a robot elbow?
Learning objectives
#
- Complete five hands-on circuit design projects:
a. Build a prototype and PCB of a breadboard power supply that accepts power from a 12 V wall supply and emits 12 V, 5 V, and 3.3 V at the same time.
b. Build a prototype and PCB of an H-bridge motor controller to make a motor spin both ways.
c. Build an electromechanical game including microcontroller, moving mechanical element, and user input.
d. Build a an internet-connected, electromechanical device that can traverse an obstacle.
e. Coordinate with other electromechanical devices in an internet-connected system.
- Distinguish between voltage and current and apply working definitions of voltage and current to explain energy transfer in simple circuits.
- Describe the relationships among voltage, current, resistance, and power.
- Gain proficiency with breadboard prototyping.
- Turn a breadboard prototype into a printed circuit board using PCB design software.
- Explain how to use transistors to control high power with low power.
- Compare and contrast different types of motors (DC, stepper, and servo) and build circuits incorporating each kind.
- Explain how an H-bridge motor controller works.
- Learn the basic code/upload/test/debug cycle for microcontrollers.
- Gain basic familiarity with microcontroller hardware.
- Gain familiarity with incorporating microcontroller hardware peripherals into circuit designs, including the i2C module, PWM module, and serial port module.
- Gain enough familiarity with Python programming to code an electromechanical game controlled by an RP2040 microcontroller.
- Describe how the internet works.
- Gain familiarity with Linux basics and explain how they relate to the functioning of a Raspberry Pi.
- Identify the main components and functions of the Raspberry Pi.
- Describe the basics types of control in the context of the motor(s) used in course projects, and RP2040 or RPi.
- Become familiar with the frequency domain and digital filters.
- Reflect on strengths and weaknesses of one’s project management approach in an open-ended design project.
- Gain exposure to managing a bill of materials, supply chain, and verification vs validation.
- Build engineering ethics fluency by exploring the impact of internet-connected electronic technologies on various stakeholders, including in environmental and societal contexts.
- Define discriminatory design, explain a case where it has occurred, and identify an approach to avoid it.