Goal
Connect duty cycle, sleep current, harvesting, and battery life to practical IoT design decisions.
Energy-Aware Design Quiz
Answer energy-design questions while an animated power model shows the cycle, budget, and decision logic behind each answer.
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A beginner-first animated quiz for IoT duty cycle, sleep mode, harvesting, battery-life, and radio-energy reasoning.
Animation
Quiz
Beginner First
Energy Design
Energy-Aware Design Quiz
Use each question as a small design investigation. Pick an answer, then watch the energy model show the cycle, budget, or decision rule that makes the answer correct.
1 of 8current question
0/0checked answers
Duty cycleactive concept
Pick an answercurrent outcome
Try First
Answer question 1, press Step, then compare the active spike with the sleep baseline.
Watch
The token, bars, evidence cards, and feedback change together as the question changes.
Why It Matters
Many IoT failures come from using peak current, daylight power, or battery capacity without averaging over time.
Question
Choose the best answer. Feedback appears immediately and the model explains the design rule.
Pick an answer to reveal the reasoning and update the diagnostic model.
52 uAaverage current
0.33%active duty
Wake spikedominant factor
Use weighted averagedesign move
Cycle View
The model shows the active burst, sleep interval, and average value for the current question.
Observe
Reading: The same device can have a high active current and a tiny average current if it sleeps for most of the cycle.
Key Formula
Iavg = (Iactive x tactive + Isleep x tsleep) / period.
Result: about 52 uA average.Design Rule
Average over the full cycle before sizing batteries or harvesters.
Peak current alone is misleading.Watch For
Short high-current events can still dominate energy use.
Reduce radio events first when they dominate.Beginner Ramp
Energy-aware design starts by averaging behavior over time. A sensor may wake for milliseconds, transmit, then sleep for minutes. Battery life depends on the average, not just the peak.
- Active: the short period when the node senses, computes, or transmits.
- Sleep: the long low-power period between useful events.
- Budget: the average power or current the battery or harvester must support.
Core Formulas
Duty cycle: active time / total cycle time.
Average current: Iavg = Iactive x duty + Isleep x (1 - duty).
Daily harvest: energy = harvested power x useful hours x efficiency.
Battery life: time = capacity / average current, with real designs derated for temperature, converter loss, and self-discharge.
Quick Reference
- Radio transmission is often the largest energy event.
- Deep sleep matters most when the device waits for long periods.
- Harvested daylight power must be spread over the full day.
- Batching readings saves energy when each transmission has a fixed wake-up cost.
Accuracy Notes
- The quiz uses classroom approximations and explicitly ignores some losses where noted.
- The LoRaWAN duty-cycle item is a simplified time-on-air example for a channel/sub-band where a 1% duty limit applies.
- Battery capacity in mAh is only directly comparable at a known voltage and load profile; the quiz item isolates the current-capacity idea.
Common Mistakes
- Using active current as if it flows continuously.
- Forgetting that solar or vibration may only be available part of the day.
- Optimizing MCU clock speed while the radio dominates total energy.
How To Use This Quiz
For each question, first estimate the dominant factor, then answer. Use Step to move through observe, calculate, decide, and optimize stages if the explanation feels too fast.
Practice 1
After question 1, change your mental model: what if the device wakes every 10 seconds instead of every 60 seconds?
Practice 2
After question 3, explain why 50 mW of daylight power does not mean a 50 mW continuous budget.
Practice 3
After question 8, identify another design where batching data would reduce radio energy.