Creating Custom Parts in Fritzing

Fritzing is an open-source prototyping platform that allows its users to easily create electrical circuits. The main advantage Fritzing has over other free circuit design tools like Eagle or KiCAD EDA is the ability to create the circuits in “breadboard” view – basically just like using real wires to connect real components on a real workbench. Fritzing has quite a few electronic parts built-in and there are third-party libraries, but sometimes, your circuit might be using some new or rare component that isn’t included in any of them. This tutorial will guide you step-by-step through the process of turning those components into Fritzing parts.

Software

• Fritzing version 0.9.3b – available from http://fritzing.org/home/
• Inkscape – available from https://inkscape.org/en/

In this guide, you will learn the basics of working with vector graphics using free Inkscape editor. We will then use the graphics to create the source files for all three Fritzing views – the breadboard view, the schematic view and the PCB view. Finally, we will add some metadata and integrate all of it into a single Fritzing part!

Step 1: Gather all the information

Before we start drawing the vector graphics and designing the part, we will need all the information we can get, mainly the physical dimensions of the part to create the breadboard view, which should have the same dimensions as the real component. The dimensions are usually included in the datasheet, so that’s a good place to start. Manufacturers tend to put them on the last few pages.

Figure 1. Part dimensions in the datasheet

Unfortunately, it won’t be always this easy. Sometimes, the part you’re designing will simply not have a datasheet; typically if it’s a breakout board. You will probably be able to find a datasheet for the module on the breakout board, but not for the board itself. That’s when you’re going to have to improvise a little. Try searching the Internet first. Even though nobody had made the Fritzing part yet, someone might have measured the dimensions for you. If the search comes up empty, then it’s time to get the caliper and start measuring.

As an example for this guide, I will be making Fritzing parts for some of the sensors from the ROHM Sensor Evaluation Kit: UV sensor (ML8511), hall-effect sensor (BD7411G) and color sensor (BH1745NUC). The steps will be almost the same for all of them, so let’s just focus on ML8511A for now. The sensor is placed on a small breakout board, and since dimensions for the breakout board is not provided we’ll have to measure most things.

Figure 2. ML8511 breakout board

To create the graphic for breadboard view, you will need at least the outer board dimensions, the position of the mounting holes and the position of the connector. All of these affect the position of the part in Fritzing and connection to other parts, so you have to be very precise!

Figure 3. The minimum required dimensions

Tip: Lots of components on the breakout board have standardized dimensions. For example, the pitch of the pin header is 2.54 mm (0.1 inch). Dimensions of components like ICs can be found in their datasheet. Measuring those is usually not a good idea, since any measurement you take will always be less accurate than the dimensions you can find in datasheet.

Since the breadboard view should look the same as the real component, it’s also a good idea to measure position of components soldered onto the breadboard, like capacitors, resistors and ICs. When measuring those, you don’t have to be as precise as with the connectors. These components don’t connect to anything other than the board itself, so the errors in their position won’t affect the position of other Fritzing parts. Still, they should be roughly in the same place in the breadboard view as they are on the real part.

Now that we have all dimensions we need, it’s time to create an accurate vector-graphic depiction of our real life component!