Summary of Exploring Eagle CAD ULPs #1 – PickUp.ULP Select Components Both in Schematic And Layout
This article introduces the "Exploring Eagle CAD ULPs" series, focusing on User Language Programs (ULPs) as C-like plugins for EAGLE. It highlights a common issue where schematic components end up scattered during board generation, violating the rule of placing connected parts together. The post describes using the "PickUp.ULP" tool to manually gather specific components like capacitors and crystals in the layout editor, avoiding tedious manual movement.
Parts used in the Exploring Eagle CAD ULPs #1 – PickUp project:
- Eagle CAD software
- User Language Program (ULP)
- PickUp.ULP script
- Schematic design file
- Board file
- LAYOUT editor MOVE tool
- C9 capacitor
- C11 capacitor
- Y1 crystal oscillator
- R1 resistor
Welcome to the first post of the “Exploring Eagle CAD ULPs” series. Every week we will publish a new post about one useful ULPs in Eagle CAD.
“ULP” User Language Program is a plain text file which is written in a C-like syntax and can be used to access the EAGLE data structures and to create a wide variety of output files, you can consider it like a plug-in for Eagle.
You can reach the posts published in this series using the following link.
When we work on schematic design, we always add parts here and there, adding a missed capacitor for a power pin of a regulator or a missed resistor for a data line and so on.
When we will generate the board file to start routing, we will find the parts scattered in the board.
The first rule in placing and routing in PCBs is to place connected components near to each other, but in the raw board file you will find every component located in a different place according to the order of adding them in the schematic.
This becomes very annoying in big designs. You need to gather the connected components manually, you will using MOVE tool for that. For example, to gather the components C9, C11, Y1 and R1 of a crystal connected to the MCU, you should run the following commands in the layout editor:
For more detail: Exploring Eagle CAD ULPs #1 – PickUp.ULP Select Components Both in Schematic And Layout
- What is a ULP in Eagle CAD?
A ULP is a plain text file written in C-like syntax that acts as a plug-in to access EAGLE data structures and create output files. - How does component placement behave when generating a board file?
Components appear scattered in the raw board file according to the order they were added in the schematic rather than their electrical connections. - Why is gathering connected components manually annoying?
It becomes very annoying in big designs because you must use the MOVE tool to physically group parts that should be near each other. - Can ULPs be used to select components in both schematic and layout?
Yes, the series covers tools like PickUp.ULP that allow selecting components in both the schematic and layout views. - What is the first rule in placing and routing PCBs?
The first rule is to place connected components near to each other. - Which tool is used to gather components like C9 and R1 in the layout editor?
The MOVE tool is used to gather specific components such as C9, C11, Y1, and R1. - What type of syntax do ULPs use?
ULPs are written using a C-like syntax. - Does this article cover multiple ULPs?
No, this is the first post of a weekly series dedicated to publishing one useful ULP at a time.
