PCB Autorouting #Freerouting #PCB @ADSKEagle

BMOW writes:

The Apple II Daisy Chainer for Floppy Emu is done, and I’ve ordered a few PCBs made for testing. This proved to be a surprisingly challenging board to lay out and route the traces. It’s a simple two-layer board, and I wanted to keep it as small as possible, so the signal routing quickly became very congested.

Hand-routing of the first 40 traces took almost a whole day of tedious work, so I finally gave up and tried autorouting the remaining 80 traces. And it worked! The result looked pretty good, too. I’m curious to know how autorouting has turned out for other hobbyists. Have you ever autorouted nearly an entire board? What were the results?

We’ve all tried autorouting with Eagle and found it lacking – here is what BMOW did:

I haven’t had good results with Eagle’s built-in autorouter, so for recent projects I’ve been using a stand-alone autorouting software package called Freerouting. It’s a Java-based app with a slightly awkward UI, but it’s impressively powerful. First you export your Eagle board file in .DSN format, using a script provided by Freerouting. Then you import the DSN file into Freerouting and let it work, running for about 1 to 15 minutes. When it’s finished you can export an Eagle session script, which will rip up all your old tracks and lay down the new ones calculated by Freerouting.

Obtaining good autorouting results requires careful setup of Eagle’s design rules. For example, the default might be to use 8 mil traces with 8 mil minimum spacing between traces, but power and ground might be treated as a separate net class requiring 20 mil traces for extra current-carrying capacity. The design rules also define what size drill to use for vias, and how close to the edge of the board it’s OK to route traces. The autorouter takes all of these constraints into account when it does its job.

Check out Freerouting here.

See the blog post for details on how the author did with Freerouting here.


Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards

Join Adafruit on Mastodon

Adafruit is on Mastodon, join in! adafruit.com/mastodon

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Join over 36,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org


Maker Business — “Packaging” chips in the US

Wearables — Enclosures help fight body humidity in costumes

Electronics — Transformers: More than meets the eye!

Python for Microcontrollers — Python on Microcontrollers Newsletter: Silicon Labs introduces CircuitPython support, and more! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi

Adafruit IoT Monthly — Guardian Robot, Weather-wise Umbrella Stand, and more!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — #NewProds 7/19/23 Feat. Adafruit Matrix Portal S3 CircuitPython Powered Internet Display!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !



No Comments

No comments yet.

Sorry, the comment form is closed at this time.