How do I know I'm grabbing the right part?

I’m a relative novice when it comes to searching for parts. I’m building a circuit board to interface with an Arduino Mega 2650, doing my initial experiments on a repurposed MKS Gen L V1.0 board - basically a Mega 2650 with RAMPS built-on.

As such, I have a LOT of connectors that fit the MKS board - they’re not special, your basic JST connectors, but I know that JST connectors come in many sizes and configurations. In the photo, for instance, I’ve got 3pin and 10pin shrouded connectors: how do I know that’s what I’m choosing in the parts bin? I see several that look similar, but it’s confusing.

  • Bill in KCMO

Measure with a micrometer. Mark with a crayon. Cut with an ax.

You likely won’t find the exact part but if you aren’t making boards (where the footprint needs to be the correct size) that shouldn’t matter. The generic connectors are by default 0.1in pitch headers, you can change the pitch in inspector for other pitches and select the number of pins you need (and Fritzing will create a connector on the fly.) So I would suggest just use a shrouded connector with the correct number of pins and you should be fine. Otherwise you would need to find or make a part for the specific connector you have (as noted, usually only if you need to make a pcb though. )


The only thing that needs to be correct is the layout of the header pins because I plan to plop it down onto a Mega 2650. Other than that, placement of the connectors is wholly arbitrary.

So, cool! Thank you.

There is a Fritzing part for the Mega 2650 which will give you the location of the headers (the Mega connectors are standard 0.1in headers which the generic connector will produce), there may also be a shield part that has the connector positions (there is one for the Uno I don’t know about the mega.)