Test Plan Development for Project
1:38
Running design review.
Reviewing the bill of materials.
Analyzing the schematic.
Analyzing the PCB layout.
Refining answer requirements.
Clarifying design state issues.
Functional requirements
| ID | Requirement | Validation Method |
|---|---|---|
| F1 | Board powers on from intended source without damage | Bring-up, current monitoring |
| F2 | Logic/control section starts consistently | Power-cycle and programming tests |
| F3 | Visual outputs behave as intended | Functional output test |
| F4 | User input/switching changes behavior correctly | Input stimulus test |
| F5 | Programming/debug interface is usable | Interface/programming test |
| F6 | All intended nets are electrically continuous | Continuity and resistance checks |
Non-functional requirements
| ID | Requirement | Validation Method |
|---|---|---|
| N1 | No excessive current draw in idle or active states | Power profiling |
| N2 | No component exceeds safe operating temperature in normal use | Thermal test |
| N3 | PCB survives normal handling and installation | Mechanical inspection and stress |
| N4 | Board remains functional after environmental exposure | Environmental test |
| N5 | Assembly is manufacturable and repeatable | DFM/assembly inspection |
| N6 | Design is free of unresolved critical ERC/DRC issues before release | Review gate |
Bench equipment
| Equipment | Purpose |
|---|---|
| Bench power supply with current limit | Safe bring-up |
| Digital multimeter | Voltage, continuity, resistance |
| Oscilloscope | Supply stability, switching, signal timing |
| Logic analyzer | Digital behavior and interface timing |
| IR camera or thermocouple | Thermal characterization |
| ISP/programming tool | Programming and verification |
| Magnification microscope | Solder and assembly inspection |
| ESD-safe workstation | Safe handling |
| Environmental chamber if available | Temperature/humidity stress |
A. Electrical Testing
| TC ID | Test Case | Procedure | Expected Outcome | Pass/Fail Criteria |
|---|---|---|---|---|
| E-01 | Visual pre-power inspection | Inspect polarity, solder bridges, tombstones, connector orientation, damaged pads | No visible assembly defects | Pass if no defect likely to cause short/open |
| E-02 | Power-to-ground resistance | Measure input rail to ground before power-up | Finite resistance, not near-short | Pass if resistance is consistent with design and not indicative of a short |
| E-03 | First power-up current limit | Power with low current limit and monitor current | No latch-up, no sudden overcurrent | Pass if current stays below set safe threshold and board remains stable |
| E-04 | Steady-state input current | Measure current after startup | Stable, repeatable current draw | Pass if within expected operating window defined during characterization |
| E-05 | Rail voltage accuracy | Measure all supply nodes | Rails within tolerance | Pass if each rail is within +/- 5% of target unless tighter limit is later defined |
| E-06 | Power-cycle repeatability | Cycle power 50 times | Reliable startup every cycle | Pass if zero failed boots |
| E-07 | Brownout behavior | Ramp supply down/up slowly | Predictable reset or shutdown | Pass if no latch-up, corruption, or excessive current |
| E-08 | Output continuity | Validate each output path electrically | All expected paths connected | Pass if continuity matches schematic intent |
| E-09 | Idle ripple/noise | Probe supply rails with scope | No abnormal ripple/oscillation | Pass if ripple is stable and no sustained oscillation is observed |
| E-10 | Input debounce/stability | Toggle switch/input repeatedly | Clean response, no chatter-induced malfunction | Pass if no missed or false events beyond agreed limit |
| E-11 | LED channel validation | Exercise all visible outputs one by one and in pattern mode | Correct channels activate with correct polarity | Pass if every channel behaves correctly |
| E-12 | Fault current check | Test safe response to brief abnormal operating condition where practical | No catastrophic failure | Pass if board recovers and no damage occurs |
B. Communication & Interface Testing
| TC ID | Test Case | Procedure | Expected Outcome | Pass/Fail Criteria |
|---|---|---|---|---|
| I-01 | Programming interface connectivity | Connect programmer and detect target | Target is recognized reliably | Pass if detection succeeds on 3/3 attempts |
| I-02 | Firmware flash and verify | Program image and verify contents | Successful write/verify | Pass if verify is clean with zero retries required beyond normal tool behavior |
| I-03 | Reset/programming sequence | Test reset entry and reprogram cycle | Consistent programming access | Pass if repeated programming succeeds |
| I-04 | Interface signal integrity | Check clock/data lines during programming | Clean levels, no stuck lines | Pass if levels meet logic thresholds and transactions complete |
| I-05 | Recovery after interrupted programming | Interrupt one programming cycle safely, then retry | Board remains recoverable | Pass if successful reflash restores operation |
C. Functional Testing
| TC ID | Test Case | Procedure | Expected Outcome | Pass/Fail Criteria |
|---|---|---|---|---|
| F-01 | Basic startup behavior | Apply power and observe behavior | Intended startup sequence occurs | Pass if startup result matches defined behavior every time |
| F-02 | Normal operating mode | Run intended primary function for 30 min | Stable operation | Pass if no reset, lockup, or visible malfunction |
| F-03 | User interaction | Operate switch through all expected states | Device responds correctly | Pass if all states are reachable and repeatable |
| F-04 | Output pattern endurance | Run output sequence continuously for 4 hr | No drift or failure | Pass if functionality remains correct throughout |
| F-05 | Simultaneous activity stress | Drive outputs while exercising inputs/programming-safe functions | No interference or unstable behavior | Pass if no missed events, resets, or corrupted operation |
D. Thermal Testing
| TC ID | Test Case | Procedure | Expected Outcome | Pass/Fail Criteria |
|---|---|---|---|---|
| T-01 | Room-temperature thermal map | Run normal mode for 30 min and capture temperatures | Hotspots identified, stable temperatures | Pass if no component exceeds its rated temperature limit |
| T-02 | Worst-case power thermal run | Operate in highest-current realistic condition for 1 hr | Temperature reaches steady state safely | Pass if junction/case estimates remain below rated limits with margin |
| T-03 | Enclosure-like airflow restriction | Repeat thermal run with reduced airflow if enclosure is planned | Predictable temperature rise | Pass if still below allowable limit |
| T-04 | Hot restart | Run hot, power-cycle, restart | Normal restart from warm condition | Pass if startup remains reliable |
E. Mechanical Testing
| TC ID | Test Case | Procedure | Expected Outcome | Pass/Fail Criteria |
|---|---|---|---|---|
| M-01 | Dimensional inspection | Measure board outline and key clearances | PCB matches fabrication intent | Pass if critical dimensions are within fab tolerance |
| M-02 | Connector/programmer mating | Insert and remove cable/programmer repeatedly | No pad lift, no intermittent contact | Pass if 20 cycles complete without damage |
| M-03 | Switch actuation life screening | Actuate switch repeatedly | Stable mechanical function | Pass if no sticking or intermittent response after 200 cycles |
| M-04 | Handling robustness | Gentle manual handling and fixture mounting | No cracked joints or detached parts | Pass if post-test inspection and function are clean |
| M-05 | Battery/contact retention if applicable | Check retention/contact pressure during movement | Reliable contact | Pass if no unintended disconnect |
F. Environmental Testing
| TC ID | Test Case | Procedure | Expected Outcome | Pass/Fail Criteria |
|---|---|---|---|---|
| ENV-01 | Cold functional test | Test at low ambient, e.g. 0 C or project target | Board starts and runs | Pass if full functionality is maintained |
| ENV-02 | Hot functional test | Test at high ambient, e.g. 50 C or project target | Board starts and runs | Pass if full functionality is maintained |
| ENV-03 | Thermal cycling | Cycle between low/high ambient 10 times | No latent failures | Pass if function before/after is identical |
| ENV-04 | Humidity exposure | Expose to moderate humidity soak if available | No corrosion-related or leakage-related malfunction | Pass if behavior remains normal after stabilization |
| ENV-05 | ESD handling check | Basic controlled ESD handling evaluation | No permanent damage from normal handling exposure | Pass if no reset or failure outside acceptable handling limits |
G. Manufacturing / Reliability Gate Tests
| TC ID | Test Case | Procedure | Expected Outcome | Pass/Fail Criteria |
|---|---|---|---|---|
| R-01 | Schematic/layout review gate | Review open ERC/DRC findings | No unresolved critical issues | Fail if critical review issues remain unresolved |
| R-02 | Assembly repeatability | Test multiple assembled units | Similar current, voltages, and function | Pass if unit-to-unit spread is acceptable |
| R-03 | Burn-in | Operate for 12 hr to 24 hr | No infant mortality failures | Pass if unit remains fully functional |
| R-04 | Regression after rework | Retest repaired units | No degradation after rework | Pass if all prior critical tests still pass |
6) Edge Cases to Include
| Edge Case | Why It Matters |
|---|---|
| Minimum input voltage at startup | Finds brownout sensitivity |
| Maximum allowed input voltage | Verifies safe margin |
| Rapid power toggling | Finds reset or latch-up issues |
| Power applied with switch active | Checks startup-state handling |
| Programming attempt during unusual board state | Checks recovery robustness |
| Cold start after long unpowered storage | Reveals weak contacts or startup issues |
| Long-duration operation | Reveals thermal drift and intermittent faults |
| Multiple outputs active simultaneously | Finds aggregate current issues |
| Open or intermittent external connection | Checks fault tolerance |
Suggested automation stack
| Layer | Recommendation |
|---|---|
| Instrument control | Python with SCPI for PSU, DMM, scope |
| Functional sequencing | USB relay / GPIO test controller |
| Result logging | CSV or SQLite with per-board serial number |
| Regression | One-button script for bring-up and flash verification |
| Reporting | Auto-generated pass/fail summary and trend plots |
8) Risks and Failure Modes
| Risk | Likely Effect | Mitigation |
|---|---|---|
| Floating nodes already seen in ERC | Unpredictable logic or false failures | Resolve or document before formal test |
| Unknown current budget | Overstress during bring-up | Use current-limited supply and characterize gradually |
| Thermal hotspots on dense LED/output regions | Reduced life or intermittent behavior | IR scan under worst-case load |
| Connector or battery contact intermittency | Random resets | Mechanical retention and contact testing |
| Incomplete requirements definition | Ambiguous pass/fail outcomes | Freeze measurable acceptance criteria before signoff |
| Prototype-only workmanship variation | False negatives | Test more than one assembled board |
10) Recommendations to Improve Test Coverage
| Recommendation | Benefit |
|---|---|
| Define explicit nominal and min/max supply limits | Makes power tests objective |
| Add a current budget table | Enables meaningful pass/fail thresholds |
| Add labeled test points on key rails/signals in next revision | Faster debug and production screening |
| Resolve current floating-pin findings before final validation | Reduces ambiguous failures |
| Document intended LED behavior/state table | Makes output testing deterministic |
| Create a golden-board reference dataset | Enables unit-to-unit comparison |
| Run at least 3 boards through the same plan | Better confidence in repeatability |
| Add a simple automated production smoke test | Shortens future screening time |
12) Suggested Deliverables
| Deliverable | Purpose |
|---|---|
| Test matrix spreadsheet | Track status by case and by unit |
| Bring-up checklist | Safe first-power procedure |
| Automated bench script | Repeatable regression |
| Thermal image set | Document hotspots |
| Final validation report | Signoff evidence |
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