The DKKAI Roadie is an add-on for the Drum Kit Kit AI (DKKAI). The Roadie allows you to change the MIDI notes of the different drum pads connected to your Drum Kit Kit AI without the need to reprogram the ATmega on the DKKAI. Which you would do normally using the Arduino IDE.
The Roadie sits on top of the DKKAI and connects with the DKKAI’s two row expansion port. On the Roadie, there are indicator LEDs to let you know if you are in programming or playing mode, and buttons to make adjustments.
To switch modes you press the Mode / Save button and it causes the DKKAI to cycle through the modes (Play -> Note program -> Aux. Program). You can customize the programming to make the Roadie affect different playing parameters.
With the updated Arduino Drum sketch (below), you can change MIDI notes of the different drum pads and in the Aux. programming mode, control Macetech ShiftBrite products with the Roadie. The ShiftBrite products are extremely cool to use with the DKKAI. Connect up to six ShiftBrite products (one per drum pad) to the DKKAI Roadie and you don't only have a Drum Kit, you have a full sound and light concert! Each time you hit a pad, the ShiftBrite will give you a blast of colorful light.
Video: Quick test of the light feedback while drumming with the DKKAI, Roadie and ShiftBrite LED modules.
The set up in the video is a cardboard box with holes to pass the wires and translucent drinking cups hot glued on top of the ShiftBrites to catch the light.
The DKKAI Roadie is available in a super easy to built kit or already assembled.
• LEDs x4.
• Mini Buttons x3.
• 470ohm resistors x4 (current limiting for LEDs).
• Six pin 90° Male header (connects to ShiftBrite products).
• Eight Pin Male Header x2 (connects to DKKAI).
• Eight Pin Female Header (solder to DKKAI to receive Roadie).
• Rubber bumper (prevents Roadie from touching DKKAI’s ATmega IC).
Using the photo below for reference insert and solder the parts. Below are a few build notes.
Insert the two eight pin female headers and solder. (Blue arrow in photo)
All of the parts on the Roadie are inserted from the top of the PCB with the exception of the two eight pin male headers, which are inserted from the bottom and soldered from the top.
You can’t get the resistors on this kit mixed up even if you tried. All four are 470ohm. Bend the leads with your fingers, insert into the spots marked R1 to R4 and solder.
Resister illustrations from Sam Engström’s web page: samengstrom.com
Install the LEDs with the longer leg going into the hole marked with the +.
Peel and stick the rubber bumper, either on the bottom of the Roadie, or stick it directly onto the ATmega near the notch.
The bumper helps to prevent the Roadie from touching the ATmega IC when the buttons are pressed.
Download the updated Drum Kit software with Roadie support: Here in the download area.
Press the Roadie on to the female pin header of the DKKAI. Make sure that all of the pins are lined up.
When you power up your DKKAI (make sure that it is loaded with the newer Drum Kit Sketch to use the Roadie), after a few seconds the Play LED will light up. You can now play your drum kit as normal.
Note: If your DKKAI has the newer Drum Kit sketch but you don’t have the Roadie installed on it, the Drum Kit will still work as it normally does. The DKKAI does not care if the Roadie is not installed and will simply ignore the extra features.
Press the Mode / Save button once, the “Note” LED will light. You are now in note programming mode.
Select drum pad:
Select the drum pad whose note you would like to change by hitting the drum pad. The “Pad Select” LED should light up.
Press the “Up” or “Down” buttons to cycle through the MIDI notes for the selected pad. Every time you press either button the note will be played through your selected output (MIDI jack or USB - Serial cable), as a preview. To hear the current selected note again, hit the selected drum pad and the note will sound. NOTE: the other drum pads are de-activated during this process.) When you are happy with the new note associated with the selected drum pad, press the Mode / Save button and the newly selected note will be saved in the the ATmega’s EEPROM.
With the Roadie, your drum kit can put on an instant light show! To do this the Roadie has a six pin connector that can connect to Macetech ShiftBrite products.
The simple way to use the ShiftBrites with the Roadie.
The ShiftBrite is a high-brightness LED module containing red, green, and blue elements and are manufactured by Macetech . It uses a simple clocked serial interface to receive a value for each color. ShiftBrite modules can be chained together and the color values are clocked from one to the other. Macetech also makes; Headerless ShiftBrites (to use your own wires), MegaBrites (a ShiftBrite with three tri-color LEDs for huge brightness), and other products such as the ShiftBar with lets you connect your own LEDs (or other LED modules ) and also has a separate power connectors for higher current projects.
The Roadie associates one ShiftBrite module per drum pad. This makes it possible to have each of your drum pads produce a different color when hit.
From the Roadie connect a six conductor cable from the six pin connector on the left side of the Roadie on to the first ShiftBrite.
NOTE: It is important to get the polarity correct. Also, the pins on the ShiftBrite marked DI, EI, LI, CI are the input pins, these connect to the Roadie.
The next ShiftBrite connects to the first ShiftBrite by taking a cable from the first ShiftBrites DO, EO, LO and CO pins (output), and connecting it to the next ShiftBrites DI, EI, LI, CI pins. Keep connecting ShiftBrites like this until you have the same number as the Drum Pads you are using.
Roadie wired up to a ShiftBrite.
C h a n g i n g Colors:
Press the Mode / Save button twice. The Aux. LED should be lit.
Select the Drum Pads whose LED color you want to change by hitting the drum pad. The Pad Selected LED should light up and the ShiftBrite for that pad should flash red once.
The Roadie adjusts the ShiftBrite’s color by allowing you to change the values for the Red, Green and Blue channels individually. When you first selected the ShiftBrite, it flashed Red showing that the adjustments you are about to do will affect the red channel.
Press the up or down buttons to change the intensity of the red channel from full on to full off. NOTE: The LED will light with all three channels, so it may appear green or blue or some mix of colors even if you are adjusting the red channel.
Once you are happy with the red channel setting you can either; Press the Mode / Save button to return to playing mode or press BOTH the Up and Down at the same time to jump to the next color channel. As you cycle from one channel to the next the LED will flash with the channel’s color briefly, and then display the current color setting as you adjust the colors. When you are done, press the Mode / Save button to return to regular playing mode.
One of the objectives of this project was to make a simple add on board. Additionally, the Drum Kit is to function normally regardless of the Roadie being connected or not.
To achieve this we didn’t want the buttons to use external pull ups, (which would not be there when the Roadie was removed, which could “confuse” the DKKAI). To do this we used a little trick, many microprocessors have something called weak-ups built in for their digital pins. A weak pull-up is basically an internal resistor connected from the pin to the high voltage source. This is used so that the pin is not floating, and it is called “weak” since it is easy for an outside signal to change the value of the pin and the signal will not be affected by the pull-up. (The condition called floating is when no signal is applied to a pin the micro-controller may read the pin as either a high or a low.)
In the Arduino IDE there is no command to activate the weak-ups, so the work around is to set the output signal on the pin to high by using digitalWrite(somepin, HIGH); and then setting the pin to be an input. This way if there in no Roadie or it is removed the DKKAI will be read a high on all the button pins. To sense a button press, the buttons simply connect to ground so that the DKKAI senses a low.
Here is the schematic for the Roadie.
DKKAI Roadie schematic.
In it’s most basic form, you could connect three buttons to Arduino digital pins 6,5 and 4. This would let you change notes.
An easy way to also use the visual feedback with the ShiftBrites would be to get a ShiftBrite Shield .
By using a ShiftBrite Shield and making a stack or Arduino - ShiftBrite Shield - Drum Kit Kit Mini Shield, you can easily connect to ShiftBrites and either use the prototyping area for buttons of a mini-bread board.
Updated Drum Kit software with Roadie support.
ShiftBrite, ShiftBar, MegaBrite and ShiftBrite Shield are trademarks of Macetech LLC.
Copyright SpikenzieLabs 2019