Shield assembly - installing pin headers

Save yourself some pain

If you haven't already read this in the instructions for installing the stacky header:

Don't even turn on your soldering iron until you're absolutely confident you know where the headers are supposed to go.

There are two sets of holes along the sides of the boards. Aside from position, they're identical in every way. That's an open invitation for Murphy's Law to smite the unwary. Trying to unsolder header is a pain in the neck.

The headers go into the outside row of holes, closest to the edge of the shield. They're outlined in green to the right. The hardwire holes are the inside row, closest to the jacks. They're outlined in red.

Use the Arduino as an alignment jig

The good news is that installing pin header is easy. You don't have to fuss with tack joints or anything like that.

It does help to use the Arduino though. There's still some slop between the holes and the pins, and pin header is even less forgiving of misalignment than stacky header.

Lay the board on the pins

And you're ready to solder.

On the tools page I said you'd need an iron that can throw some heat around. This is where you need it. Pin header has a lot of mass compared to other components, and the phosphor bronze of the pins conducts heat well. The pins are also long and thin, which means they radiate heat well.

You need to heat the top of the pin to about 350C (the temperature where solder melts) faster than the pin can transmit heat away, and definitely before it can spread the heat across enough surface area that the rate of cooling matches the rate of heating.

If the solder doesn't melt onto the pin in the first 1-2 seconds, stop trying. You just don't have enough heat. Turn up the heat control, or find a larger iron.

Done (top)

Once you have the heat right, though, the rest of the job is trivial.

Done (bottom)

A view from underneath, to hammer home the idea that the headers go in the outside row of holes. Yeah, I harp on that a lot, but I've made the mistake myself, and I designed the darn things.

For me, trashing a part is annoying, but at least I have a few hundred spares over in the bins. You probably don't have that luxury, and it sucks to put a project on hold because you have to order a replacement part. It's even worse when you lose a part to a mistake that could have been avoided with ten seconds of thought.

display panel