Add Hardware Design Tips Guide to System Design Wiki

_data/navigation.yml

@@ -25,6 +25,8 @@ wiki:
         url: /wiki/system-design-development/subsystem-interface-modeling/
       - title: In Loop Testing
         url: /wiki/system-design-development/in-loop-testing/
+      - title: Hardware Design Tips
+        url: /wiki/system-design-development/hardware-design-tips/
       - title: How to design a robotic state machine
         url: /wiki/system-design-development/how-to-design-a-robotic-state-machine/
   - title: Project Management

wiki/system-design-development/hardware-design-tips.md

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+---
+# Jekyll 'Front Matter' goes here. Most are set by default, and should NOT be
+# overwritten except in special circumstances.
+# You should set the date the article was last updated like this:
+date: 2026-05-01 # YYYY-MM-DD
+# This will be displayed at the bottom of the article
+# You should set the article's title:
+title: Hardware Design Tips
+# The 'title' is automatically displayed at the top of the page
+# and used in other parts of the site.
+---
+
+This article covers practical hardware design tips for robotics engineers across
+mechanical and electronics/mechatronics design. These are drawn from hands-on
+experience building robotics systems and are meant to complement formal coursework.
+Topics include CAD workflows, FEA simulation tool selection, PCB design for
+debuggability, power circuit simulation, and wiring best practices including
+emergency-stop wiring, color coding, and cable management.
+
+## Mechanical Design
+
+### 1. Learn CAD with the ModelMania Problems
+
+After completing introductory tutorials, work through **SOLIDWORKS ModelMania** problems. The archive has 26 years of free problems at different difficulty levels: [SOLIDWORKS ModelMania Archive](https://blogs.solidworks.com/products/solidworks/26-years-of-model-mania/)
+
+A few personal tips:
+- Try not to exit a sketch until it is fully constrained. Better yet, use parametric variables so the model's most important dimensions remain editable and independent.
+- Try rebuilding the same part in a different way after you finish it; this broadens your design perspective.
+- Open-source tools such as [FreeCAD](https://www.freecad.org/) can be a good option when avoiding CAD software license dependencies. It also has a free API and CAD kernel for exploring generative CAD design using MCP servers and LLMs.
+
+---
+
+### 2. FEA Simulation
+
+Finite element analysis (FEA) simulates how a design responds to forces, heat, and other physical effects before it is built. It helps newcomers identify potential structural, thermal, or fluid-related issues early in the design process.
+
+Get the free ANSYS student license through CMU: [CMU Software Access](https://www.cmu.edu/computing/software/access.html)
+
+ANSYS is widely used in industry. It covers structural, thermal, and fluid simulations.
+
+COMSOL is useful for research work that couples multiple physics, such as heat, structure, and electrical effects. It is more flexible and common in academic papers.
+
+Examples of usage:
+- Checking if a robot link will break under load: ANSYS
+- Thermal analysis on a motor or PCB: ANSYS
+- Piezoelectric actuator or anything multi-physics for a paper: COMSOL
+- Airflow around a drone → ANSYS Fluent
+---
+
+## Electronics & Mechatronics Design
+
+### 1. Drop Eagle. Learn KiCad.
+
+Autodesk Eagle is being phased out and the free version has a tiny board size limit. KiCad is free, open source, has no restrictions, and is what you'll want if you ever start a company and don't want to pay software licensing fees forever.
+
+KiCad has everything: hierarchical schematics, 3D board preview, SPICE simulation, custom symbol/footprint editors. It's also what a lot of startups and open hardware projects use now.
+
+To get started:
+- Do the [DigiKey KiCad 9.0 Tutorials Playlist](https://www.youtube.com/watch?v=0Q6gU7-QqUg&list=PLEBQazB0HUyQ5YJSdCBb79orXaR3Uk5vm&index=2) (<1h play time) to get a really quick jumpstart as it covers the full schematic to layout to gerber to BOM workflow.
+- Practice making your own symbols and footprints. You will always have some weird component that's not in any library.
+- Always check community footprints against the actual datasheet before trusting them.
+- Check your Gerbers in [Tracespace](https://tracespace.io/view/) before submitting to a fab.
+
+For prototyping boards: JLCPCB and PCBWay both work great with KiCad exports, cheap and fast.
+
+---
+
+### 2. PCB layout tips
+
+A board that works in simulation or on paper but has zero test points or indicators is a nightmare to debug in real life. Here are some general PCB design tips:
+
+- **Separate power and signal-processing electronics on the board** — This helps prevent high-EMI/EMC devices, such as inductors and switching regulators, from introducing noise into low-power signal and GPIO traces.
+- **Copper thickness** — Specify copper trace thickness (usually in oz) when placing a PCB order. If the traces are too thin, the circuit may not carry its designed current load.
+- **Test points** on every power rail and important signal. Just a pad. Saves hours.
+- **Status LEDs** on your power rails (3.3V, 5V, 12V etc.) with a current limiting resistor. You want to immediately know if a rail isn't coming up.
+- **Current sense resistors** on high-current paths — small value (0.01–0.1Ω), measure voltage across it with your ADC or multimeter.
+- **Label your connectors** on the silkscreen. Pin 1 marker, net name, polarity. You will forget this in the lab at 2am one day.
+
+---
+
+### 3. Simulate Your Power Circuit Before You Spin the Board
+
+Most board failures are catchable before you even order the PCB.
+
+Use **LTspice** (Analog Devices) as it has models for most common components. Use it to:
+- Check your gate drive waveforms
+- Catch oscillation in feedback loops (buck converters especially)
+- Test your design at edge cases (min/max input voltage, max current)
+
+---
+
+### 4. Wiring and wire management
+
+- **Use PG cable glands and conduits** — Use [PG glands](https://www.mcmaster.com/products/pg-glands/cord-grips-2~/) and [cable conduits/hose carriers](https://www.mcmaster.com/products/cable-conduit/) to provide strain relief for cables entering and leaving enclosures, while improving water and dirt resistance for the electronics inside.
+- **Use [DIN rails and DIN-Rail Mount Terminal Blocks](https://www.mcmaster.com/products/din-rails/)** - They are the industrial alternative to breadboards and WAGO connectors. They provide a standardized wire connection interface.
+- **Use color-coded signal wires** — This simple practice is often overlooked, but it can prevent burnt ICs and shorted Jetson Nanos. General color schemes are given below:
+  - VCC|GND: RED|BLACK
+  - SDA|SCL: YELLOW|WHITE
+  - CAN-H|CAN-L: WHITE|BLUE/BLACK
+  - UART TX|RX: GREEN|WHITE
+  - PWM: ORANGE
+- **Twist differential-pair wires** — For CAN and RS-485, physically twist wire pairs together to reject common-mode noise. If a CAN bus drops frames or reports errors, untwisted wires are a likely culprit before software issues.
+
+  Never twist I2C wires together. I2C is not a differential signal, and twisting can introduce interference that prevents the bus from working.
+
+- **Emergency-stop wiring** — Do not wire an emergency stop directly into a high-current power wire, because a decelerating motor's back EMF can cause sparking at the switch contacts. Use a relay or DC contactor, a flyback diode across the control-circuit terminals, and an RC snubber across the relay contacts to limit voltage spikes when disconnecting the load.
+
+## Summary
+These are just starting tips, design only comes from experience!
+
+## See Also
+- [Printed Circuit Board Design](/wiki/system-design-development/pcb-design/)
+- [Mechanical Design](/wiki/system-design-development/mechanical-design/)
+- [Cable Management](/wiki/system-design-development/cable-management/)
+
+## Further Reading
+- [KiCad Getting Started — DigiKey YouTube Playlist](https://www.youtube.com/watch?v=0Q6gU7-QqUg)
+- [SOLIDWORKS ModelMania Archive](https://blogs.solidworks.com/products/solidworks/26-years-of-model-mania/)
+- [LTspice Simulator — Analog Devices](https://www.analog.com/en/resources/design-tools-and-calculators/ltspice-simulator.html)

wiki/system-design-development/index.md

@@ -16,6 +16,9 @@ The **System Design and Development** section provides comprehensive resources a
 - **[Finite State Machine Implementation Guide for Robotics](/wiki/system-design-development/finite-state-machine/)**
   Provides a structured approach to managing complex robot behaviors through states, transitions, and actions. Covers theoretical foundations and implementation in ROS and embedded systems.
 
+- **[Hardware Design Tips](/wiki/system-design-development/hardware-design-tips/)**
+  Offers practical guidance on CAD, FEA, PCB layout, circuit simulation, wiring, and cable management for robotics projects.
+
 - **[Hardware-in-Loop and Software-in-Loop Testing](/wiki/system-design-development/in-loop-testing/)**
   Discusses HIL and SIL methodologies for testing real-time embedded controllers, with specific use cases like ADAS and autonomous vehicles.