LibreSolar schematic symbols library
This library collects all symbols used in the different Libre Solar designs. It should be embedded as a git submodule in a folder called "library" inside the KiCad project directory.
As the Standard KiCad symbols might change without prior notice, all symbols used from the built-in library should be copied into a project specific library or this general Libre Solar library.
Library design rules
The design rules are based on the KiCad Library Convention with some exceptions.
- Using a 100mil grid, pin ends and origin must lie on grid nodes.
- Origin is placed in the middle of symbol.
- Field text uses a common size of 50mils.
- The Value field is prefilled with the object name.
- Description and keywords properties contain the relevant information.
- For components with a single default footprint, footprint field is filled with valid entry of the format "Footprint_Library:Footprint_Name" and is set to invisible.
- The style of basic shematic symbols (resistor, capacitor, diodes, etc.) should follow the IEC 60617-2 standard.
Custom ICs (black-box components)
- Pins are grouped logically, not necessarily by pin number.
- Whenever possible, inputs are on the left and outputs are on the right.
- Power supply pins (GND and VCC) are placed left or right. Top and bottom of the symbol are reserved for name and value:
- Reference designator centered at the top
- Component value centered at the bottom
Schematic layout rules
- In order to be compatible with existing libraries, the grid setup should be set to 100 mils.
- The overall schematic should be grouped in hierarchical sub-schematics for easier understanding. The default schematic sheet size should be A4.
- The pins of two devices must always be connected with a wire. It is not allowed to place two devices with their pins together without a wire.
- The text size should be 50mil for standard text and 100mil for headers.
- Each component should have the following component property fields:
- Datasheet (optional)
- Supplier (optional)
- OrderNumber (optional)
- Remarks (optional)
- If the tolerance or voltage of a part is relevant, it should be added in the remarks field and displayed in the schematic.