Building the SpikenzieLabs Calculator Kit

Getting to grips with soldering and making something useful!

Soldering practice

The only soldering experience I had at school was literally soldering two wires, and other than this there was recently one workshop I attended which involved soldering.

Since I didn't have a great deal of previous experience I thought it would be a good idea to practice on a scrap piece of perfboard before starting the build.

Getting started

After unpacking the electronics and acrylic parts I got to do my first bit of soldering.

The battery holder soldered onto the surface of the PCB and doing this was much easier than I had anticipated. I found using blu tack to secure the battery holder down while soldering it helped a lot, as this prevented the holder from moving while it was soldered.

Inserting the resistors and capacitors

This stage was very simple and bending the legs as close to the body of the resistor made it easier when it came to getting the legs in line with the holes, and pliers helped this process immensely.

The instructions advise that painter's tape can be used to hold the resistors in place while soldering, but alternatively I found that blu tack worked just as well.

The only issue I had was that because the components are so close together it's difficult to get the soldering iron close enough to the pads, and the closeness made it very easy to create a solder bridge between components.

Buttons

This stage was rather time consuming — a total of 68 (17 buttons x 4 pins) pins to solder takes quite a while. It's important to make sure that the pins on the buttons are aligned properly, so that none bend when inserting them into the PCB, which also makes the buttons a better fit and easier to solder.

LED module spacer

This is piece of plastic that goes behind the LED modules. The instructions do warn you that this part is very fragile, and I was being extremely careful, or so I thought, and still ended up breaking it!

Mounting the LED's

This was easy, and again it advises the use of painter's tape, but I found that blu tack worked just as well here too. Soldering the LEDs was time consuming due to the sheer number of legs to solder, and I found at this point I was starting to get the hang of things more and soldering was becoming much easier.

The instructions tell you to solder in columns, and this does work but yet again the components are very close together making it difficult to get the soldering iron between them. I found that instead of trimming the legs at the end of this stage, if you do it as you go along it makes it easier to access the pads.

Preparing the ATmega328 IC

This step is incredibly fiddly, because the pins are sightly flared out from manufacturing and it makes it difficult to get them in line with the PCB holes. The LEDs are in the way so you can't use your fingers to bend the pins into place, and I found the use of a flat head screwdriver helped.

Laser cut housing construction

Assembling this was the most difficult part of all. The pieces fit together nicely but due to there being so many layers it is difficult to align the screws to secure it together.

Conclusion

As far as DIY electronics kits go I think this must be one of the trendiest: the clear housing gives it a contemporary feel. The instructions are very simple and easy to follow, and the end result is ergonomic and aesthetically pleasing!