Drum and guitar amp or Dramp. When I googled the word dramp I found out that it means "something that is unfortunate or displeasing", we'll see....
For my Final Project my plan was to build a practice guitar amp with sound pads where one could store sounds f.ex. drums and play while practicing playing guitar.
It soon came clear to me that I would not have time to do all that I wanted to do so I focused on making a soundpad.
Building the casing
The first step in building the soundpad box was to prepare the wood. I was using a plank of Rohan wood that I got from a local forrestry and I had to level it and thin it down to 10mm thickness.
I used the Shopbot and did couple of passes milling away 3mm in each pass. Then after measuring the plank I did a final pass milling away 1mmm to get the material thinckness I was aiming for.
In Fusion360 I designed the box and layed out all the different sides of it, chosing the router bits and passes needed to cut the box out in the Shopbot.
I had to use 3 different routerbits and different setups for the milling, clearing out material, cutting with a V-bit and cutting holes with a straight bit.
Then I simply glued the pieces together, gave the box a little bit of sanding and coated it with linen oil.
Building the frame
I decided to have the frame for the soundpad separate for easy assembly and access. In Fusion360 I designed the frame and then milled it out in the Shopbot.
I used a plank of hard wood that I had laying around and had the ideal material thickness.
Making the sound pads
I decided to make the sound pads out of silicone. I designed a mold in Fusion360 and milled it in the Roland MDX40 machine. Then I mixed the silicon and poured it in the mold. I had made capasitive sensors by soldering pins on small copper plates for each pad and I sank them in the silicon.
In the laser cutter I made a plate out of plexy for the the silicone pads to sit on. The plexy has holes in it for the pins on the sensors. I glued the sensors on the plexyplate and layed the whole thing down on the wet silicon.
I decided to have on 100k potentiometer to have the option of controling frequency or even volume of the soundpad
Making a button for the potentiometer
In Fusion360 I designed a button for the potentiometer and 3D printed it in the Ultimaker.
The Soundpad Computer
After doing some tests with an Arduino computer and my capacitive sensors I started designing the main control board for my soundpad. The aim was to make a board that could receive serial signal from 5 capacitive sensors, convert to media signal and send it to the speaker.
The microchip I used is the atmega328p au 1518. I used this microchip because I needed many pinouts for my capacitive sensors, 2 for each sensor, 10 pinouts in the whole.
After designing the board in Eagle (see "My Final Project Work Files" in My Workfiles) ) I milled the board in the Roland MDX-40.
The next step was to solder the components on my board and check all the connections using a multimeter.
Programming with my board Arduino IDE