1d93d47097
- 12V power + 3 CAN connections per module - Modeled after SWYFT CANnect after critical CAN failures - Middle Canjector schematic (EasyEDA, 2026-04-09) - 120Ω switchable termination, power LED, WAGO terminals
3.0 KiB
title, tags, type, owner, status, sources
| title | tags | type | owner | status | sources | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Canjectors — Chris's Custom CAN Bus Interconnect System |
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hardware-spec | 2890 | active |
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Canjectors — Custom CAN Bus Interconnect System
Overview
After experiencing critical CAN bus failures during competition, Chris designed the Canjector system as a robust interconnect solution for Team 2890's robot. Modeled after the SWYFT CANnect concept but with custom design work, Canjectors provide reliable CAN + power distribution at all critical connections.
The design philosophy: prevent wiring failures from killing the robot mid-match.
Design Basis
Chris studied the SWYFT CANnect system as inspiration:
- Run CAN bus + 12V power over standardized cabling
- Easy connector system (WAGO lever terminals)
- Built-in CAN termination options
- Robust form factor
Canjectors go further with custom modifications for Team 2890's specific failure points.
Current Design: Middle Canjector
The schematic shows the "middle" Canjector variant with:
- 12V power passthrough
- 3 CAN connections (RJ45 connectors)
- WAGO terminal blocks for clean wiring (2601-1104 series)
- 120Ω termination resistor (R4) between CAN signal lines — switchable
- Power indicator LED (green, 0603) with 470Ω current limiting resistor
- 2-pin header for additional configuration
Key Features
- Dual CAN paths — each Canjector bridges multiple CAN segments
- Integrated termination — 120Ω resistor switchable per segment
- Power LED — visual confirmation that 12V is present
- RJ45 connectors — industry standard, easy to cable, robust
- WAGO 2601 series — tool-free, reliable terminal connections
- Designed in EasyEDA — schematic dated 2026-04-09
Files
- Schematic:
sources/2890/canjector-schematic.png - CAD (if available): link to repo TBD
Connection to Training
For students: CAN bus failures are among the most frustrating problems in FRC — a loose wire or failed connector kills the whole bus. The Canjector system teaches:
- Redundancy — when one path fails, traffic routes around it
- Termination — 120Ω at each end of the bus, switchable at intermediate nodes
- Visual debugging — power LEDs let you confirm connectivity at a glance
- Modular design — if one Canjector fails, replace it in minutes
Why This Matters
Chris experienced critical CAN failures at competition. The Canjector system is a direct response — solving the failure mode with custom hardware instead of hoping the stock connectors hold. This is the kind of real-world engineering that separates good teams from great ones.
Notes for MrC
This is a confidence builder for the training vault — it shows Chris's practical engineering under pressure. Good story for students: identify the problem, study existing solutions, design your own, build it, test it. The full engineering cycle, not just code.