Join DPRG on March 22, 2025, 10:00AM CT, at the Dallas Makerspace for a presentation “ROS2 Navigation and Linorobot2” by DPRG member Paul Bouchier.
Presentation overview
Why ROS2 navigation? ROS2 is the most widely used robot SW platform, and it has a powerful map-based navigation system.
Why Linorobot2? Linorobot2 is a very flexible, open SW configuration built on top of ROS2 which enables hobby-level mobile robots (< $150) to use ROS' map-based navigation stack with zero to just a little programming depending on what you want to do.
Paul will explain ROS’ navigation concepts and how to configure your robot as a Linorobot and demonstrate how to use ROS’ navigation system.
Note: Featured image generated with help from AI – ChatGPT.
Join DPRG on February 22, 2025, 10:00AM CT, at the Dallas Maker Space for a presentation “KiCad for Robots” by DPRG member Doug Paradis.
Presentation overview
KiCad Overview and Setup
KiCad is a suite with a schematic editor, PCB editor, symbol editor, and footprint editor
It was recommended to install the “Freerouting” plugin
Create a new project directory with subdirectories for footprints, symbols, and 3D models
The schematic screen includes a title block that can be edited. Page size can be changed in page settings
Schematic Editor
The schematic editor has tools for adding symbols, power symbols, wires, and “no connect” flags
Unconnected pins must be marked as such to avoid errors during the electrical rules check (ERC)
Wires should be labeled for grouping into net classes
Different types of labels include individual wire labels, net class directives, and global labels
Creating Custom Symbols
A tool was presented for generating symbols for modules or ICs: http://kicad.rohrbacher.net/quicklib.php
Key steps include specifying the component name, number of pins, and pin configuration (e.g., dual in-line (DIL))
Pin types (input, output, power, etc.) should be set to make the ERC as useful as possible
Ground pins are always considered power inputs
A project symbol library can be created to store custom symbols
The symbol editor is used to create a new library, and the generated symbol file is placed in the project symbol directory
The new library can then be added to KiCad
ERC and Net Classes
The ERC icon is used to check for errors in the schematic
A common error is a missing power flag on a power trace [23]. Power flags tell the ERC that power nets are connected to a power source
A net is a group of connected components, such as VCC or ground
Net classes allow design rules to be changed for specific nets
Each net can only be part of one net class
Net Class Setup
Net classes can be set up via Schematic Setup
Net classes can be assigned to nets using the net class directive too
Footprint Assignment
The footprint assignment tool is used to assign a physical footprint to each schematic symbol
Parts are mostly standard parts like connectors, resistors, LEDs, and capacitors
Modules may require finding or building a footprint
The internet is a good source for finding footprints
It is important to verify the accuracy of downloaded footprints
A project footprint library can be created
PCB Editor
The PCB editor has tools for selecting items, showing the rat’s nest, adding footprints, and defining rule areas
The edge cut layer defines the shape of the board and any holes through the board
Auto Routing
After assigning footprints, the “magic autorouting button” can be used
It was mentioned that Java may be required for the auto-router
Board borders need to be added
Board Shape and Design
Custom board shapes can be created in inkscape and imported
It was recommended to set the copper to edge clearance to one millimeter to prevent clipping during board fabrication
Fill zones can be added to the board
Gerber Files and Manufacturing
Gerber files are generated for manufacturing
It was recommended to use a Gerber viewer to inspect the generated files
JLC’s PCB site has instructions for generating Gerber files
A DFM (Design for Manufacturability) check can be performed on the JLC PCB site
Additional Tips
Printing a 1:1 copy of the PCB layout and placing the parts on it can help verify the design
Mounting holes can be added as components in the schematic
note: Featured Image generated with help of AI – Microsoft Designer.
