6 Specialized Testers • ±2% Measurement Accuracy • Complete Per-Unit Traceability • Database-Backed Quality Metrics
This project demonstrates a complete production-grade automated test infrastructure for validating diverse power supply topologies. The system performs intelligent multi-point validation with real-time parameter monitoring, database-backed traceability, and QR-code linked test history for every manufactured unit.
Design and implement a universal testing platform for heterogeneous power supply types:
- 6 Distinct Topologies: AC/DC mains input (ACPD), multi-output supplies (HDR20), 48V Constant Current/Voltage (DCC48XX, CCCV48XX), USB Power Delivery (DC-PD), high-current 3A USB-C (USB-C-3A), Modbus-controlled multi-scenario testing (DCP48M), and standalone 15W offline validation (DIG-CCCV-15W)
- Precision Voltage & Current Measurement: ±2% accuracy across entire operating range with real-time averaging and noise filtering
- Real-Time Status Monitoring: Status LED verification throughout test execution to confirm device operation
- Intelligent Test Sequences: Configurable multi-voltage testing, load profiling and connector rotation validation
- Complete Traceability: UUID per test run with QR-code encoding enabling instant customer access to test history
- Database Integration: MySQL backend storing all measurements, enabling batch analysis and quality trending
A modular automated testing ecosystem consisting of:
- 6 Specialized Testers: Each optimized for a specific PSU topology with topology-specific measurement hardware and test procedures
- Testers 1-5 (ACPD, HDR20, DCC48XX/CCCV48XX, DC-PD/USB-C, DCP48M): Raspberry Pi with custom measurement head designed for each topology - providing GPIO control, I2C sensor coordination, and ADC/DAC measurement via dedicated interface boards
- Tester 6 (DIG-CCCV-15W): Standalone system using Raspberry Pi Pico with integrated measurement capability - designed for portable field deployment without database connectivity
- Hardware Measurement Cores: ADC/DAC precision measurement, color sensors for LED/RGB status verification, relay feedback for pass/fail indication, and thermal monitoring via sensor integration
- Database Backend: MySQL persistent storage with UUID-linked QR-codes enabling per-unit traceability and historical measurement tracking
- Production Integration: QR-code scanning interface connecting manufacturing test results to customer-facing web dashboard
- Iterative Hardware Refinement: Multiple revisions optimizing connector interfaces, load application reliability, and thermal monitoring accuracy
- Main Controller: Raspberry Pi with C application layer
- Custom Measurement Head: Topology-specific interface board with:
- ADC/DAC for precision voltage and current measurement
- Color sensors (I2C) for LED/RGB status validation
- Relay contacts for DUT control and pass/fail indication
- GPIO expansion for topology-specific control signals
- Communication: USB/UART to measurement head + Ethernet to database backend
- Topologies: ACPD, HDR20, DCC48XX/CCCV48XX, DC-PD/USB-C-3A, DCP48M
- Microcontroller: Raspberry Pi Pico (RP2040) with C firmware
- Integrated Measurement: On-board ADC, GPIO control, I2C/UART interfaces
- Standalone Operation: No database connectivity - results stored locally in flash memory
- UART Interface: For configuration during test setup and result download for later database import
- Topology: DIG-CCCV-15W portable field tester
- ADC: 12-16 bit precision for voltage/current measurement
- DAC: Programmable reference generation for load control
- Sensor: Color/proximity sensors for LED validation via I2C
- Interface: I2C for sensor coordination, GPIO for relay/control signals
- Thermal: Integrated temperature measurement via ADC channels
- Feedback: Relay contacts for pass/fail status and DUT control
| Layer | Technology | Purpose |
|---|---|---|
| Application | C | Test orchestration, parameter control, result logging (all testers) |
| Driver | C/GPIO/I2C/UART Libraries | Hardware interface abstraction, sensor communication |
| Measurement | C with Sampling & Filtering | Voltage/current acquisition with averaging and calibration |
| Configuration | JSON/INI Files | Mode-specific tolerances, test parameters, sensor limits |
| Database | MySQL Backend (Testers 1-5) | Persistent storage of all measurements and test results |
| Communication | Ethernet/USB/UART | Status reporting and result upload to database (or local storage for Tester 6) |
Purpose: Comprehensive testing of AC/DC power delivery topologies for universal mains compatibility.
Test Sequence:
- AC Input Connection: 230V AC mains voltage connected at primary input
- USB-C Power Delivery: PD voltage profiles (5V, 9V, 12V) applied via USB-C connector
- Connector Rotation: USB-C cable rotated 180° during testing to verify bi-directional contact integrity
- Full-Load Testing: All PD voltage levels tested under full-load conditions with continuous measurement
- Status LED Monitoring: Verifies status LED remains active throughout entire test execution
- Voltage Stability: Verifies output voltage regulation and frequency stability throughout test sequence
- Isolation Verification: Galvanic isolation validated between primary and secondary sides
Key Metrics: Input voltage stability, load regulation, isolation resistance, protection response time.
Tester Unit |
Device Under Test |
Purpose: Advanced validation of multi-output power supplies with cross-load scenarios and thermal characterization.
Test Sequence:
- AC Input Connection: 230V AC mains voltage connected at primary input
- Output Load Selection: Manual slide switch selects target measurement voltage for each test cycle
- Dual-Pin Load Connection: Two pins contact and apply full load to the selected output
- Multi-Voltage Testing: All output voltages tested sequentially under full-load conditions
- Channel Independence: Each output voltage measured independently with precision measurement
- Status LED Monitoring: Verifies status LED remains active throughout entire test execution
Key Metrics: Per-channel accuracy (±2%), cross-regulation, cascading protection timing.
Tester Frontend |
Device Under Test |
Purpose: Sophisticated validation of Constant Current / Constant Voltage topologies with RGB startup sequence verification and high-current operation.
Test Sequence:
- Device Selection: Display menu selects which PSU variant to test (CCCV4805, CCCV4812, CCCV4824, DCC variants)
- Pin Contact: When DUT is inserted, two pins automatically contact and establish connection
- DC Power Input: 48V DC input applied to the selected device under test
- Voltage Measurement: Selected output voltage measured under full-load conditions
- RGB Startup Detection: Monitors color sensor for RGB LED sequence indicating proper initialization
- Status LED Monitoring: Verifies status LED remains active throughout entire test execution
- Full-Load Testing: All CC/CV variants tested under full-load conditions with continuous verification
Key Metrics: CC/CV accuracy (±1.8%), mode transition time, LED indication reliability.
Tester Unit |
Active Testing |
Purpose: Comprehensive testing of Power Delivery profiles and high-current USB-C implementations.
Test Sequence:
- Device Selection: Display menu selects PD voltage profile (5V, 9V, 12V) and test mode (standard PD or 3A mode)
- USB-C Connection: USB-C connector inserted for physical and electrical connection
- PD Profile Testing: Multi-voltage testing with full-load current application
- 3A Mode Testing: Special USB-C 3A mode tested at 5V only with 3A load applied
- Connector Rotation: Tests rotation of connector (up/down orientation) to verify bi-directional contact and data line integrity
- Status LED Monitoring: Verifies status LED remains active throughout entire test execution
- Voltage Stability: Monitors output voltage regulation under full-load conditions for each profile
Key Metrics: PD accuracy (±2%), connector reliability (10k cycles) 3A current compliance.
Tester Configuration |
Testing in Progress |
Purpose: Modbus-controlled scenario-based testing for advanced 48V converter characterization across multiple topologies.
Test Sequence:
- Modbus Configuration: Controller sends scenario definition via Modbus (voltage selection, current profile, duration)
- Multi-Voltage Testing: Sequential testing at different voltages with full-load current applied to each
- Scenario Execution: Predefined test scenario loaded and executed with real-time parameter adjustment
- Load Application: Programmable electronic load applies specified current profile matching DUT characteristics
- Measurement Logging: All measurements streamed to database with per-second granularity
Key Metrics: Modbus response time, multi-voltage accuracy (±1.8%), extended reliability.
Purpose: Portable field-deployable tester for 15W CCCV converters with standalone operation without database connectivity.
Test Sequence:
- Current Application: External pin provides constant current load based on selected voltage
- UART Communication: UART interface for configuration during test setup and verification during test execution
- LED Status Monitoring: Confirms output status indicator operation during test
- Multi-Voltage Testing: Tests 2-3 voltage points per DUT (e.g., 10V, 24V, 60V for full characterization)
- Standalone Results: Test pass/fail determination made locally without database connectivity
Key Metrics: Standalone reliability (no network dependency), voltage accuracy (±2%), UART communication robustness.
| Parameter | Specification | Implementation |
|---|---|---|
| Voltage Measurement | ±2% Accuracy | 12-bit ADC with sampling |
| Current Measurement | ±2% Accuracy | Shunt measurement + differential amplification |
| Thermal Measurement | ±1°C | Integrated thermistor sensors via ADC |
| Tolerance Validation | Mode-specific | INI-based configuration per PSU topology |
| Test Duration | Configurable | 1-20 seconds per unit (DUT dependent) |
| Result Traceability | UUID per run | Unique identifier with QR-code encoding |
- Platform: MySQL with persistent storage
- Metrics Logged: All voltage, current, thermal, and efficiency measurements
- Traceability: UUID-based tracking linking physical QR-code to test results
- Query Capability: Production batch analysis, failure trending, quality metrics
- Export Format: CSV, JSON for statistical analysis and reporting
📱 Scan the QR-Code to View Test Report:
https://digitalpowersystems.eu/q/?u=jdXR5NacRT6MlYM56yddAA
Each PSU ships with a unique UUID - scan to access complete test history and measurements
- Per-Unit Data Access: Every customer can scan the QR-code on their purchased PSU to access the complete test report and measurement history for their specific unit
- Lifetime Traceability: Manufacturing date, test conditions, voltage/current profiles tested, and pass/fail status permanently linked to the physical product
- Quality Verification: Customers verify the exact test parameters their unit underwent before leaving the factory
- Batch Analysis: Production teams identify quality trends across manufacturing batches and correlate failures to specific design revisions
- Audit Trail: Complete operational history supports product warranty claims and regulatory compliance documentation
Challenge: Design a flexible testing platform that accommodates vastly different power supply types (ACPD, HDR20, DCC48XX, CCCV48XX, USB-C, DCP48M) while maintaining precision and reproducibility.
Solution: Modular architecture with:
- Topology-Agnostic Measurement Core: Shared ADC/DAC hardware with mode-specific calibration
- INI-Based Configuration: Per-topology test parameters, tolerance thresholds, and test sequences loaded at runtime
- State Machine Framework: Universal test orchestration logic accommodating different test sequences
- Plug-and-Play Test Functions: Individual test routines for each topology without core system modification
Why It Matters: Reduces development cost per new topology while maintaining quality consistency across product line.
Challenge: Enable production line users to track test results via simple QR-code scanning without requiring technical knowledge.
Solution:
- UUID Generation: Unique identifier per test run (Base64 encoded for URL compatibility)
- QR-Code Encoding: UUID embedded in scannable QR-code label
- Database Linking: QR-scan retrieves complete test record including all measurements
- Web Dashboard: Customer-facing interface showing pass/fail status and detailed metrics
- Historical Tracking: All tests for a given unit linked for lifetime traceability
Why It Matters: Bridges gap between manufacturing and customer - every sold unit has verifiable test history.
Challenge: Ensure test infrastructure reliably validates thousands of units without manual intervention or frequent recalibration.
Solution:
- Configuration Management: All parameters in external INI files (no firmware recompilation)
- Automatic Calibration: On-device offset/gain adjustment performed at startup
- Error Recovery: Graceful handling of sensor failures with user-friendly error messages
- Watchdog Protection: Hardware watchdog prevents firmware lockup during test
- Extended Logging: Complete test execution log for debugging failed units
Why It Matters: Demonstrates understanding of production constraints and reliability requirements.
- Raspberry Pi - Main controller for Testers 1-5 running C-based application
- Raspberry Pi Pico - Microcontroller for Tester 6 (standalone DIG-CCCV-15W) with C firmware
- C Programming Language - Complete application implementation for all testers (measurement acquisition, test orchestration, device control)
- MySQL - Persistent storage of all test results and metrics (Testers 1-5)
- KiCad - PCB design for custom measurement heads (topology-specific interface boards)
- LTspice - Circuit simulation for precision measurement validation
- Git - Version control for firmware and configuration management
This project demonstrates comprehensive expertise in:
| Competency | Implementation |
|---|---|
| Embedded C Development | Cross-platform C applications for both Raspberry Pi and RP2040 microcontroller |
| Single-Board Computer Integration | Raspberry Pi controller architecture with custom measurement head coordination |
| Microcontroller Programming | RP2040-based C firmware with integrated measurement and local storage |
| Precision Measurement | ADC/DAC calibration, noise filtering for ±2% accuracy across multiple platforms |
| Hardware Integration | I2C sensor coordination, GPIO control, custom PCB interface boards |
| Database Design | MySQL schema for efficient test result storage and historical tracking |
| Application Architecture | Multi-topology testing framework with platform-specific C implementations |
| Production Engineering | Traceability systems, QR-code integration, scalable test infrastructure |
- Universal Validation: Not a single-purpose tester—comprehensive framework supporting 6+ topologies
- Production Grade: Deployed in manufacturing with proven reliability (99.8% uptime)
- Traceability Integration: Every unit has verifiable QR-code linked test history
- Precision Performance: ±2% measurement accuracy across entire operating range
- Database Integration: Persistent storage enabling quality trending and batch analysis
- Scalability: Architecture supports adding new topologies without core system modification
Test Completes → UUID Generated (Base64)
↓
QR-Code Encoded (UUID + Timestamp)
↓
Physical Label Attached to Unit
↓
User Scans QR-Code
↓
Web Dashboard Queries MySQL
↓
Test Results Displayed: ✅ PASSED
├── Voltage Accuracy: 48.02V ±0.2V
└── Current: 1.205A ±2.1%
Upstream (What Gets Tested):
- ✅ ACPD Power Delivery Supplies (230V AC input)
- ✅ HDR20 Multi-Output Converters
- ✅ DCC48XX Single-Output 48V Supplies
- ✅ CCCV48XX Dual-Mode 48V Converters
- ✅ DC-PD & USB-C-3A Chargers
- ✅ DCP48M Multi-Mode 48V Systems
Downstream (Who Uses Results):
- Production Quality Assurance
- Customer Support (via QR-code)
- Product Engineering (trend analysis)
- Compliance Documentation (regulatory tracking)
This comprehensive testing infrastructure was developed as part of advanced power electronics and embedded systems engineering:
- Focus Area: Automated quality assurance for diverse power supply topologies
- Development Approach: Iterative refinement, production-based feedback, continuous capability enhancement
- Team: Individual contributor with support from power electronics domain experts
- Deployment: Active production use with proven reliability metrics