diff --git a/sources/2890/canjector-schematic.png b/sources/2890/canjector-schematic.png new file mode 100644 index 0000000..7ebd43f Binary files /dev/null and b/sources/2890/canjector-schematic.png differ diff --git a/sources/2890/canjectors.md b/sources/2890/canjectors.md new file mode 100644 index 0000000..963966a --- /dev/null +++ b/sources/2890/canjectors.md @@ -0,0 +1,72 @@ +--- +title: "Canjectors — Chris's Custom CAN Bus Interconnect System" +tags: + - hardware + - electrical + - can-bus + - 2890 + - custom +type: hardware-spec +owner: 2890 +status: active +sources: + - "https://swyftrobotics.com/products/swyft-cannect-wiring-system" +--- + +# 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. \ No newline at end of file