Digikey made Scheme-It. Scheme-It is an online schematic and diagramming tool that allows anyone to design electronic circuit diagrams. You can utilize an integrated electronic symbol library and the Digi-Key component catalog, as well as share or export drawings. The tool includes a comprehensive electronic symbol library and an integrated Digi-Key component catalog that allows for a wide range of circuit designs. Additionally, a built-in bill of materials manager is provided to keep track of parts used in a design.