Tango to Eagle Netlist Converter: Troubleshooting & Best Practices

From Tango Netlist to Eagle Schematic: A Complete Conversion Workflow

Overview

This workflow converts a Tango-format netlist into an Eagle-compatible schematic/netlist, producing files usable in Autodesk Eagle for PCB layout. It covers file preparation, parsing mapping, symbol and footprint assignment, connectivity validation, and final import into Eagle.

1. Prepare files

• Gather: Tango netlist file(s), component library (Tango and Eagle), and any CSV mapping tables.
• Backup: Make copies of original files.
• Normalize encoding: Ensure UTF-8 and consistent line endings.

2. Inspect Tango netlist structure

• Identify sections: header, component declarations (refs/values/footprints), pin lists, net definitions.
• Record fields: reference designator, value/part name, package/footprint, pin-to-net mappings, net names.

3. Create mapping table (Tango → Eagle)

• Columns: Tango part name, Tango footprint, Eagle device/symbol, Eagle package, Pin mapping.
• Populate from libraries; for unmatched parts, assign closest Eagle equivalent or mark for manual creation.
• Save as CSV for automated scripts.

4. Convert netlist format

Option A — Scripted conversion (recommended)

• Write a script (Python) to:
  • Parse Tango netlist into internal representation (components, nets, pins).
  • Apply mapping table to translate part names/packages and pin orders.
  • Emit Eagle-format netlist (.net) or an XML/CSV Eagle import that matches Eagle’s netlist schema.
• Key details:
  • Preserve reference designators and net connectivity.
  • Reorder or remap pins when package pin numbering differs.
  • Generate warnings for unmapped parts or pin mismatches.

Option B — Manual conversion

• Use spreadsheet to rewrite component and net tables into Eagle’s expected CSV columns.
• Manually check pin mappings.

5. Handle symbols & footprints

• For matched parts: ensure Eagle libraries contain required symbols/packages.
• For mismatches: create Eagle device with correct symbol and package; verify pad names/numbers match mapping.
• Check package rotations and pad shapes.

6. Validate connectivity

• Load converted netlist into a netlist validator script or into Eagle’s import utility.
• Verify:
  • Net counts match original.
  • Each component’s pins connect to the same nets as in Tango.
  • No floating pins unless expected.
• Use a diff of net→pin lists between original and converted to detect discrepancies.

7. Import into Eagle

• Use Eagle’s netlist import (File → Import → Netlist) or open the netlist as project input.
• Review error/warning messages from Eagle and resolve library or package issues.
• Place components and run ERC/DRC checks.

8. Post-import checks

• Run Eagle Electrical Rule Check (ERC).
• Visually inspect critical nets (power, ground, differential pairs).
• Run schematic-to-board synchronization if moving to board layout; ensure no netlist merges/splits occurred.

9. Troubleshooting common issues

• Pin numbering mismatches: Revisit mapping table; confirm package pad names.
• Missing libraries: Add or create Eagle libraries before import.
• Net name changes: Normalize net naming rules (Eagle may disallow certain characters).
• Unmapped parts: Temporarily map to a placeholder device and replace later.

10. Automation tips

• Version-control mapping CSVs and conversion scripts.
• Log all warnings and create a checklist for manual fixes.
• Build unit tests comparing random component net connections between source and converted netlists.

Example: minimal Python conversion outline

python
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# parse tango -> build components, nets
# apply CSV mapping
# emit eagle netlist format (CSV/XML)

Deliverables checklist

• Converted Eagle netlist file
• Mapping CSV used
• List of unmatched parts/pin warnings
• Validation report comparing source and converted connectivity