15 July - Take prototype to PCB with Eagle

A project log for IP control for inexpensive line following robots

A project for my grandchildren to first build line-following robots then convert them to being controlled by their phones and tablets.

jedjed 07/15/2019 at 21:400 Comments

My favorite PCB creation tool for hobbyists is Eagle, now from Autodesk.

Eagle Overview

Imagine my surprise when the Eagle I have installed, 5.11.0, has been superseded by 9.4.2. My how versions fly! I downloaded and installed the new version and started to get used to the new interface. Then I took my notebook page (as shown in the last log) and drew the schematic in Eagle. The only hitch was the NodeMCU pinout.

Fortunately, some kind soul has thought of other Eagle users and published a library containing various ESP8266 layouts. The last update is even the one I want. The commit log says "esp8266modules.lbr    Added WeMos D1 mini module - 3 years ago" and that is EXACTLY what I want.

ESP8266 Eagle Library download

I've downloaded that library and used Eagle's library manager to "use" it. Then I finished drawing the schematic to match my notebook and used that schematic to construct a board layout.

The board matches my stripboard prototype with the addition of two jumpers that allow use of OLED modules that switch their V+ and Gnd leads.

Once the PCB looks done, I print it actual size and try the parts on it. This lets me check some obvious things like clearances and some less obvious like part mistakes.

The IC socket is a stand-in but tests fit. I'm happy with it.