Sleep-Wake Duty Cycle Animation

Sleep-Wake Duty Cycle Animation

Interactive IoT power-management workbench for sleep, wake, sense, compute, transmit, and return-to-sleep states.

animation
power-management
duty-cycle
sleep-mode
battery-life
architecture
intermediate
A learner-ready sleep-wake duty-cycle animation with scenario presets, stage timeline, average-current math, polling versus interrupt latency, battery-life estimates, caveats, and quick reference support.
Animation Power Management Duty Cycle Battery Life

Sleep-Wake Duty Cycle Animation

Watch an IoT node move through sleep, wake, sense, compute, transmit, and return-to-sleep states. Change the timing and currents to see how average current, polling latency, and battery life move together.

0.12% Duty cycle
35.5 uA Average current
6.2 years Battery life estimate
15 min Worst-case alert delay
TryChoose Timer polling, set Report interval to 60 s, Radio time to 100 ms, and Sleep current to 5 uA.
ObserveDuty cycle and Average current shrink as the 60 s cycle spends more time asleep, but Worst-case alert delay approaches the polling interval.
ExplainAcross a 60 s Report interval, Average current is the time-weighted sum of wake, sense, compute, transmit, and sleep states; interrupt wake changes activity timing.
Technical boundariesThe first-order cycle omits regulator quiescent current, startup peaks, sensor stabilisation, radio retries, battery voltage/temperature curves, self-discharge, interrupt false positives, and capacity derating.
Colour keyfundamentals identitycurrent / primaryreference / datasuccesscautionerror / failure
1. Sleep Most of the cycle should be spent in low-current sleep.
2. Wake Startup overhead matters when active bursts are very short.
3. Sense Sensors may need warm-up or stabilization time.
4. Compute Filtering and decisions can happen before radio use.
5. Transmit Radio time is often the active-state energy peak.

Cycle Timeline

The timeline is visually compressed so the short active burst remains visible. Calculations use the actual interval and stage durations.

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Sleep wake state machine Sleep -- Wake -- Sense -- Transmit -- Compute --

Scenario Controls

Choose a device pattern, then tune interval, active work, radio time, sleep leakage, and battery size.

Timer latency is bounded by the interval. Interrupt alert latency is the active chain.
Seconds between routine wake cycles.
Sensor warm-up, sample, and conversion time.
Transmit plus receive window or acknowledgement time.
Clock startup, regulator settling, and firmware boot work.
Current while the radio is active.
Include MCU, regulator leakage, memory retention, and always-on detectors.
Battery-life estimate uses 80% usable capacity for reserve and derating.

Duty Cycle

Fraction of the report period spent awake.

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Average Current

Time-weighted current across all stages.

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Battery Life

First-order estimate using daily mAh draw.

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Latency Meaning

Timer polling and interrupt wakeup are different designs.

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Duty Cycle Quick Reference

What to calculate

  • Active time per report period.
  • Stage current for wake, sensor, compute, radio, and sleep.
  • mAh per day, not only instantaneous current.
  • Worst-case timer latency or interrupt response time.

Common mistakes

  • Calling sleep current zero.
  • Ignoring sensor warm-up time.
  • Using radio peak current for the whole cycle.
  • Claiming lower duty cycle always gives acceptable latency.

Design choices

  • Timer wake suits slow sensing and routine reporting.
  • Interrupt wake suits alarms, but the detector still consumes power.
  • Hybrid wake uses periodic reports plus event-triggered alerts.
Technical Accuracy Notes

Model boundary

This page is a first-order teaching model. Real designs must measure startup current, regulator quiescent current, battery temperature behavior, retransmissions, and self-discharge.

Latency wording

A timer-only node may wait almost one full interval before noticing an external change. An interrupt node can wake quickly, but its always-on detector current belongs in the sleep-current budget.

Battery estimate

The displayed life estimate uses 80% of nominal capacity. Coin cells, alkaline cells, and lithium packs behave differently under pulse load and low temperature.

Practice Prompts

Find the dominant state

Set the report interval above 30 minutes, then raise sleep current. Explain why sleep can dominate even when the radio current is much larger.

Meet a latency target

Use timer polling for a leak sensor and reduce the interval until the worst-case delay is acceptable. Compare the battery-life cost.

Use an interrupt

Switch to interrupt mode for an alarm. State which always-on component must remain powered and how that changes the sleep-current assumption.

Sleep Mode Optimizer

Compare idle, light sleep, deep sleep, and hibernate behavior.

Power Profile Analyzer

Inspect current profile bursts and optimization targets.

Power Budget Calculator

Build a complete load-side and battery-side budget.

Battery Life Estimator

Explore derating, reserve, and lifetime estimates.