From 70a5e48ab8ae2a389e5eda7a5441c14250fbf994 Mon Sep 17 00:00:00 2001 From: MrC Date: Mon, 4 May 2026 01:48:26 +0000 Subject: [PATCH] =?UTF-8?q?Update=20Canjectors=20=E2=80=94=20full=205-vari?= =?UTF-8?q?ant=20family=20documented?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit - Start: 1 CAN, 1 12V (bus origin) - Minor: 3 CAN, 1 12V (intermediate) - Middle: 3 CAN, 2 12V (intermediate + power) - Major: 6 CAN, 2 12V (end of chain) - Endz: 1 CAN, 1 12V + USB diagnostic (start or end) - All have shunt-activated 120Ω termination --- sources/2890/canjectors.md | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/sources/2890/canjectors.md b/sources/2890/canjectors.md index 57dd2be..19f27bf 100644 --- a/sources/2890/canjectors.md +++ b/sources/2890/canjectors.md @@ -52,15 +52,19 @@ The schematic shows the "middle" Canjector variant with: ## Design Variants -Chris designed three Canjector variants for different positions in the CAN bus topology: +Chris designed five Canjector variants to form a complete CAN bus distribution system. All variants support configurable termination via a shunt jumper — populate the shunt to activate 120Ω termination at any position in the chain. -| Variant | Position | CAN Termination | Notes | -|---------|----------|----------------|-------| -| **Start** | Bus origin (PDH side) | No termination at this end | Upstream CAN connector from PDH | -| **Middle** | Intermediate nodes | Switchable 120Ω | 3 CAN connections + 12V passthrough | -| **Major** | Bus terminus (end of line) | Fixed 120Ω termination | Final node — TERM switch, 120Ω resistor populated | +| Variant | CAN connections | 12V outputs | Termination | Typical use | +|---------|----------------|-------------|-------------|-------------| +| **Start** | 1 | 1 | Shunt-activated | Bus origin at PDH | +| **Minor** | 3 | 1 | Shunt-activated | Intermediate node | +| **Middle** | 3 | 2 | Shunt-activated | Intermediate node + power distribution | +| **Major** | 6 | 2 | Shunt-activated | End of chain (large node) | +| **Endz** | 1 | 1 | Shunt-activated | Start OR final terminator — diagnostic USB interface | -**Major variant:** Blue PCB, three identical sections, TERM label, 120Ω termination resistor visible, PWR LED, 2-pin header. This is the end-of-bus variant — fixed 120Ω termination resistor must be populated. Zip file in `canjector-gerbers/` directory. +**All Canjectors share the same termination philosophy:** no fixed termination at any position. Use a shunt jumper to enable 120Ω termination exactly where the bus physics require it. This eliminates the need for separate "terminating" and "non-terminating" variants. + +**Endz** is unique — it's the diagnostic variant with a USB Type-B connector for direct laptop-to-CAN connection. Meant to serve as either the first or last device in the chain. Currently experiencing design problems; no working units on hand. ## Connection to Training @@ -84,6 +88,10 @@ This is a **confidence builder** for the training vault — it shows Chris's pra |------|-------------| | `canjector-schematic.png` | Middle Canjector — EasyEDA schematic | | `canjector-start-pcb.png` | Start variant — PCB layout (red solder mask) | -| `canjector-major-render.png` | Major variant — 3D render, blue PCB | +| `canjector-minor-render.png` | Minor variant — 3D render, blue PCB | +| `canjector-major-render.png` | Major variant — 3D render, blue PCB, 6 CAN ports | +| `canjector-endz-render.png` | Endz variant — USB-to-CAN diagnostic interface | | `canjectors.md` | This documentation file | -| `canjector-gerbers/` | Manufacturing files (Gerbers + drill files + How-to-order guide) | \ No newline at end of file +| `canjector-gerbers/` | Major variant manufacturing files | +| `canjector-minor-gerbers/` | Minor variant manufacturing files | +| `canjector-endz-gerbers/` | Endz variant manufacturing files | \ No newline at end of file