This page shows how to assemble the hardware of this version.
The front side of the PCB shows the outline of the Ardu, the micro switches, the joystick, two sliders and the MIDI jack.
On the back side you find another slider, a push button and two SMD switches.
The Fiddly SMD Bits
The first step is to get the two resistors and the diode on there. They all are place on the front side of the board.
Hand soldering SMD parts is possible and actually not that hard. I found that it is best to first get some solder on the pads, then put the parts in place, and then reheat the solder with a very fine tip. A pointy tool to hold the part in place helps a lot. This one would have been ideal but good tweezers work in a pinch.
Solder paste didn’t really work for me, it was messy and the connection was weak. When ordering parts you should consider buying more of the tiny parts than needed because they get lost stupidly easy.
The last picture shows the orientation of the diode. I’ll have to figure out how to get stuff printed on my boards.
The less fiddly SMD parts
Then add the two switches and the push button. These look easy, just hold them in place with some kind of clamp and solder them. Consider to use double sided tape to stick the switches to the board. Without mounting tabs they are relative fragile otherwise. Also you should be careful to not squash the button by using too much force.
The micro switches
Then the micro switches for the valves are soldered in place. Note that their intended orientation is indicated by the circle in the switch’s footprint. It shows where the actual button is supposed to go.
To get them seated properly they can be clamped down as well, even if their bent legs do a pretty good job of holding them.
This one is easy: Put in place, secure it there, flip the board over and apply solder where legs stick out. I recommend to begin with the four big ones in the corners and then ditch whatever you used to clamp it down.
The MIDI jack
This may prove more complicated than it looks. While the pattern of the five contact pins is pretty much agreed upon, the placement of the two extra pins that provide mechanical stability, may vary wildly, even within the line up of a single manufacturer.
In the picture you see a metal shielded connector made by Hirschmann that had been purchased because the plastic variant was out of stock. Note that the footprint doesn’t match. In this particular case it is safe to snip off the two extra pins since shielding is no real concern here. I will add the holes to the next iteration.
The battery holder
Cut the leads to the desired length, the battery will be held in place by stick on velcro. The connector goes to the back side and the positive wire is connected to the power switch. The next iteration will have silkscreen, I promise.
The pressure sensor
The pressure sensor is put into place. The pin with the notch goes into the square pad and the whole sensor points down
Take another look at the battery connector and make sure that the red lead is in the pad that is directly connected to the power switch. After this step the solder joints of the battery connector will be virtually inaccessible.
Then get your sliders, clamp ’em, solder ’em and be over with it.
There are several variants of these. In the pictures you see a model with dust protection. They also miss the two large mounting pins that would go into the large rectangular pads you see next to the slider that is shown above.
If you have the choice, get the ones without the protective cover, at least for the octave slider. The cover adds a lot of friction and the slider already isn’t ideal from an ergonomic standpoint. Also: If your sliders have the big mounting pins, you can bend these down to the board to get an even more robust joint. This also helps with placing the battery at the back of the board.
The Arduino micro
Finally the controller board is added. This can be done with two rows of pins or with sockets. Pins give you a slimmer profile but removing the Arduino will be a pain in the ass. You probably shouldn’t use simple pin headers with this version of the PCB.
If you want to use female headers on the board, the recommended way to get them aligned is this:
- Put pin headers in your Arduino micro and push that combination carefully into a breadboard
- Solder the pins to the Ardu
- Pull the Ardu and its new legs from the breadboard and carefully push the female headers onto the pins
- Now take all this to the front side of the board, secure it in its place and solder the sockets to their pads
Following these steps makes sure that the sockets will be perfectly aligned with the pins on the Ardu. Bonus: If you managed to mount the controller facing the wrong way, you can now simply pull it and turn it around.