ECE 110 Final Project for Fall 2021

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Final Design Project, Fall 2021

Obstacle Avoidance with a Push-Button Stall

Final Project Day 3 Considerations

As we move into the final week of Final Project Design, we would like to make sure all teams are prepared for writing the final report and providing a strong video presentation. Furthermore, we would like to make sure all individuals are prepared for the Question and Answer Demo session where TAs will ask each student some questions regarding the project and request a hardware-based measurement in defense of their response. This short list will give you and your team items to consider as you complete your project.

The Team-Submission Video

Rubric

Will be prerecorded and due before the final meeting the week of Nov. 29 through Dec. 3.
The video should start with a circuit schematic (hand drawn or otherwise) of the entire project solution. This page should also include the netIDs of all students who contributed to the team production of the video, in fact, each student should be highlighed in a small portion of the video regarding their contribution if possible.
With the car's motors disconnected, use the M2k to demonstrate the Trigger of the ultrasonic sensor on channel 1 (the triggered channel) and the echo signal on channel 2.
With the motor's connected, demonstrate the reaction of the wheel(s) to the sensor(s)'s input.
With the car near a wall, demonstrate how it reacts to the wall.
Videos should be no more than 5 minutes in length and in mp4 format.

Design Report

Rubric

Design is often based on assumptions grounded in science and math. After a prototype is constructed, those assumptions can be challenged by empirical data and the project design altered in response. In the building of the car, there are many things you might consider with respect to both analysis and design. While you do not need to include all of these items in your project, each is within your reach and each will strengthen your project.

The 9-to-5-volt converter was designed for 50 mA drawn by the load. Did you explain your design (math and science)? What does your load actually draw from this new 5-volt source? Could this knowledge change your design thinking? Did you consider using IV characteristics to model the Thevenin-equivalent circuit of this 5-volt source? Comment: always be careful to consider items like power limits when making attachments to devices for IV characterization.
Did you both predict (math and science) and then verify (empirical analysis) the RC time constant for the delay circuit? Did you meet the customer's request? Would the use of the M2k oscilloscope improve your ability to demonstrate your technical competence?
The potentiometer is more prone to damage than is the use of discrete resistors used below their power rating. If you used potentiometers on your board, might you consider using your digital multimeter to first measure, then replace the values of the potentiometer with discrete resistor components? Comment: Some designs may want to retain the potentiometer for long-term tuning which is fine, but you might mention why.
Did you revisit your final design to clean it up, perhaps using smaller wires (less prone to breaking), better choices of wire color (easier debugging), fewer components where possible (considering cost), and less space on the board?
Did you give consideration to what the 5-volt output and the 9-volt output are driving? Did you make it difficult to make a mistake where these two sources might be shorted together?
With the car functioning, did you give thought to how you could make it work better? Track closer or further from the wall? Don't forget to ask your customer (TAs) for feedback!
Are you prepared to answer questions regarding your part of the circuit? How might you double [the duty cycle] or decrease [the period]. What design criteria caused you to choose the design values you used?

Rubrics

Final Design Report (written)
Final Design Team Video

Final Project Description

Primary Responsibility	Resources	Comments


Outline of the Final Project	Wall-follower #1 (short version) [.mp4] Wall-follower #2 (long version that exposes an accecptable error when the car loses sight of the wall) [.mp4]	You and your team will work to build a wall-following (one sensor) or an obstacle-avoiding (two sensor) car for which the ultrasonic sensor(s) will cause the car to move away from walls and other obstacles. A wall-following solution must have a (no-wall present) tendancy to drift to the right that is countered by a corrective steer to the left as it nears a wall. The single sensor will face to the right. The obstacle-avoidance solution should go relatively straight until an obstacle on the right or left results in a proper correction for avoidance. The dual sensors will face one to the right, one to the left. Furthermore, a push-button will enable the car's handler to temporarily stall the wheels to make it easier to set the car down and make quick adjustments or repairs or to make it easier to disconnect the battery if bigger alterations are needed or your are finished with your demo. The stall is temporary and will be adjusted to last for 5-10 seconds according to an RC time constant. The distribution of duties below is not equitable (it rarely is on any project), but this is also a team activity where all students stand to benefit from a functional solution. As a teammate finishes their individual activity, they need to pivot assistance to another teammate to keep the project moving towards a successful completion.

Team Exercise: Division of Duties		As a team determine which student will take each of the tasks defined above. If a team has only 3 team members, the teammate 4 tasks may be assumed by the entire team. If a team has only two members, teammate 1 tasks should be eliminated next (and the non-optimized DC converter used). The final project work is allocated three weeks (prior to Fall Break). Attendance in lab is mandatory for all team members. The TA will provide a weekly grade based on observed progress on the project. In the first week, your team will begin discuss the project, make a plan for completion, and make progress on the documents provided in the resource section. By the third week, the project should be primarily finished and working. Use your time in lab wisely to get TA assistance with issues you encounter. This project will be challenging for many students, so be sure to schedule time outside of the weekly lab meetings to make progress so that your lab time takes advantage of the TA resource. We will also provide periodic "clues" to students who need them, but you must earn them with your hard work!

Teammate 1: 9 volt to 5 volt converter	Zener-based DC converter Design [.pdf] [.docx]	This teammate will need to design a 9-volt to 5-volt converter. This is necessary because the ultrasonic sensor has an operating voltage of 5 volts. The goals of this teammate are to 1. Consider the Zener diode and diode circuits to design the DC voltage converter to meet constraints and 2. Validate that design by modelling its behavior according to Thevenin theory (take some data points!). This project is the simplest of all the options and teammate 1 is expected to finish first and pivot assistance to another teammate as soon as possible. If a team has only two members, this position may be either assigned to another member or this task removed and replaced with the non-optimized implementation of the Zener-based DC voltage converter.

Teammate 2: Square-Wave Oscillator for Triggering	A non-optimized DC converter [.pdf] Information Sheet on US sensor [.pdf] [.docx]	This teammate will need to design a square-wave oscillator for triggering the ultrasonic sensor so that it emits ultrasonic pulses properly. Most of the literature will recommend using the Ardunio to generate such a trigger, but that solution is costly and does not allow the opportunity for a deeper understanding of the function of ultrasonic sensing. The goals of this teammate are to 1. Consider the travel of acoustic signals with reflections in a design of a trigger pulse and 2. Validate that design by documenting behavior of the trigger used on a real ultrasonic sensor. Since the sensor operates on 5-volts, teammate 2 may need to provide 5 volts from a source not yet available from Teammate 1. This could be done by accessing the 5-volt output from the M2k (which would remain tethered to your computer) or building a non-optimized version of a Zener voltage converter. Both the power to the US sensor and the max trigger voltage need to be limited to approximately 5 volts. This project is the most challenging of the options and teammate 2 will benefit with assistance from the others as they are able. Eventually, all teammates will meet at this step to integrate and finish a functional vehicle.

Teammate 3: Push-Button Delay	A timed delay project.[.pdf]	This teammate will need to design a delay that utilizes an RC time constant in a circuit solution that temporarily turns off both car motors. Again, most literature will encourage robotic enthusiasts to use a microprocessor to achieve such behavior, but a simple analog circuit design can be much smaller and more cost effective. The goals of teammate 3 will be to 1. Determine how the motors could be stalled and 2. determine how to couple that motor-drive design into a push-button controlled RC circuit. The design choices should be discussed in a manner that would aid a future student in determining which design choices have flexibility and which do not. You should be confident that your prior lab exercises have set you up well for this task. This exercise requires mostly brainstorming, but the build itself should not be too complex. Teammate 3 will benefit from talking to others to generate an efficient solution and then will pivot to aid another teammate.

Teammate 4: Systems Engineer		This teammate will have flexibility to see that the overall project moves forward in a productive manner. The responsibilities of Teammate 4 include 1. Setting deadlines for various aspects of the project, 2. seeing that all teammates know how to contribute to the project each week either moving their own sub-project forward or assisting the others, 3. assist on sub-projects that require help, 4. overseeing (and documenting) the process of system integration from the sub-projects of all teammates, and 5. ensuring a quality report (as per the rubric) where all teammates have contributed with rough equity and the project development is matched with technical reporting centered on ECE 110 concepts. Teammate 4 should be outgoing and knowledgeable. If the team consists of only three members, this position may be allocated to another teammate or dispersed among the members.


Individual + Team: Record a Video Demonstration Write the Report	Written Report Guideslines [.pdf] (to be updated for final project soon!) Example *Final* Report at the ECE 110 level: [.pdf]	Each Individual will assume responsibility for one aspect of the car as outlined above and it is their responsibilty to produce the first draft of the corresponding section of the final report body. Each section should be limited to 1 to 2 pages in length keeping the final report less than 10 pages maximum. The Team is expected to pull the report together and add the title, abstract, introduction and conclusion while ensuring the final project reads as one voice. Use the rubric to consider how well the document serves as a technical report. A rubric for a (team-produced) video recorded in advance of the final project presentation will appear soon. The video should show the working features of your car so that the demo with the TAs can focus on Question and Answer to test your understanding of the solution you and your team has accomplished.

Extra Credit: Work on these additional modules and/or Add a Bonus Feature for up to 50 points each. Note that your lab credit will not exceed 30% of the course weight (lab credit is capped at 100%).	Oscillator Analysis [.pdf] Electret Microphone (starter) [.pdf] Microphone with Voltage Gain (extends the starter exercise) [.pdf]	Add something unexpected to the function of this car. You will want to 1. Choose and build a feature for this car and 2. Discuss the design or analysis elements of this add-on feature. It is important that this add-on feature be tied into one (or more) concepts covered in ECE 110 or, perhaps, an extension of circuit theory not covered. This student might consider working with another sensor from the kit or coupling "old" concepts to make something new happen. Examples: A loud clap will stop the car instead of the button. Lights (or sounds?) will accompany the motion of the car as it "sees" and avoids obstacles. Check-engine light...A warning light will illuminate if a circuit component gets warm with operation. You can be creative and willing to analyze the circuit behavior (investigate IV characteristics, evaluate a circuit, or other ideas the TA may be able to recommend). Full integration with the car will only be possible after the car becomes functional.