This is an individual assessment competency hurdle task. If you have questions or need help, ask privately on the forums. Students caught working together will be awarded an automatic fail.

If you do not know where to begin, make sure you have completed the timer activity in the final lab.

Instructions

1. Design and Build the following circuit as described below on a single breadboard.
2. Practice using the kit multimeter to measure voltage and current.
3. Practice using the lab digital storage oscilloscope to make measurements and to display waveforms from the circuit.
4. Practice drawing circuit diagrams on paper.
5. When ready, attend your scheduled assessment slot and get your work marked off. If you fail to complete or meet the requirements of any item/part, you will be marked as not satisfactory and be required to return in the following week to re-attempt it.
6. Completing this task within the first three weeks of assessment (i.e. week 8-10) will award 'second chance' bonus marks of 2% which can be used to 'make up' for marks lost from the project.
7. Failing to complete this task by week 12 will result in an automatic fail of the unit with a mark cap of 45%. A late completion penalty of 5% will apply if you fail to complete this within the four week assessment period (week 8-11).
8. Students who miss attempts (scheduled assessment period) due to valid special consideration reasons (unwell, etc) can request for a late completion penalty waiver by emailing [email protected] with the reason and evidence.

In-Person Assessment Requirements

1. Your completed physical circuit.
2. You must bring writing material (ideally a pencil and an eraser).
3. You must bring a copy of the calculations made. If you did this on a calculator or app, make a copy of these calculations onto a physical document.
4. You will need to use the digital storage oscilloscope to make the requested measurements (your assessor will instruct you on what measurements to take) and to set up a clear view of the output waveform of your circuit appropriately.
5. You will need to demonstrate to your assessor that you can use the kit multimeter to measure voltage and current in your circuit at the requested nodes.
6. You will need to demonstrate a clear understanding of the circuit designed and how it works during the interview.
7. You will be given a sheet of paper when you arrive in person - fill your student details out and draw the circuit diagram of your circuit, ensuring that this diagram meets all circuit diagram standards.

Circuit Requirements

Design a circuit using at least one logical gate (implementing MOSFETs) and a 556 timer that alternatively flashes two LEDs (red and green).

• Use jumper wires (from your kit) to build this circuit

• Black for GROUND connections
• Red for POWER connections
• any other color for internal connections (done consistently)

• Your circuit must be powered from the Arduino 5V pin.
• Your circuit must be completely electrically controlled (no software running to create said effect)
• No components should be directly connected to the power/ground rails.
• Your circuit must contain at least one 556 timer
• The LEDs must flash at a frequency of 260Hz (+/- 10 Hz)
• The duty cycle at which the green LED flashes must be between 50% and 80% (e.g. if the green LED is on for 75% of the time, the red LED is on for 25% of the time)
• You can use components provided to you in your kit.
• Your LED must not be directly driven by the 556 timer, due to the IC being unable to output sufficient current to large loads that could draw large currents (assume that your LED simulates a large current load)
• You should label the green LED as D₁, and the red LED as D₂.
• You will need to put a current probe point at the following nodes

• Timer VRC
• Timer Output

• Your circuit will be marked based on calculated theoretical values instead of physical values due to variances in component tolerance.