Drosophila Vial Tracking System (DDB)¶

Overview¶

A Python-based system to manage Drosophila vials, including: - QR-code based identification - Automated label printing - Full lineage tracking - SQL-based database backend - Qt GUI for lab use

Core Components¶

Database¶

Recommended: PostgreSQL

Key tables: - Users - Organisational Units - Donors - Genotypes - Genotype Status - Vials - Vial Status - Audit Log

Features: - Foreign key relationships - Partial unique index for active vial print codes - Full-text genotype search

Hardware¶

Device: Star Lite 5 (Ubuntu tablet with camera)
Printer: Brother QL-820NWB
Labels: DK-11204 (17x54 mm)

QR Code System¶

Payload format: ddb:1:vial:<vial_id>?pc=<PRINT>&db=<DBID>

Micro QR preferred
Must fit ~13–14 mm square
Fallback: human-readable print code

Print Code¶

Base32 (Crockford alphabet)
4–5 characters
Optional checksum

Software Stack¶

Backend: FastAPI + SQLModel
GUI: PySide6 (Qt)
QR: Segno
Camera: OpenCV
Printing: brother_ql

Workflows¶

Import / Initialise¶

Create genotype
Create vial
Print label

Copy Vial¶

Duplicate vial
Link parent
New print code

Cross Vial¶

Two parents
New genotype required

Flip Vial¶

Create new vial
Decommission old vial

Group Flip¶

Batch version of Flip
Optional strict pairing mode

Status Change¶

Modify vial/genotype status

Decommission¶

End-of-life for vial

Reports¶

Vial details
All vials (active/all)
By user
By organisational unit
By genotype
By gene (text search)
By donor
By status

Key Design Decisions¶

PostgreSQL over SQLite for concurrency
QR codes over barcodes for density
Audit logging for all critical actions
Separation of genotype and vial states

Future Development¶

Mobile apps (Android/iOS)
Cloud deployment
Automated backups
Advanced lineage visualisation

Milestones¶

Database + API
Label printing
QR scanning
Core workflows
GUI
Deployment

Notes¶

Always confirm label printing via re-scan
Maintain strict lineage tracking
Prioritise usability in lab conditions