Step 1: Assemble the SD Interrupter

R1, R10 10kΩ (brown black orange)
R2, R7, R8     1kΩ (brown black red)
R3, R9 100Ω (brown black brown) (note that on early boards, R9 is mislabeled)
R4 100kΩ (brown black yellow)
R5 3.3kΩ (orange orange red)
R6 220Ω (red red brown)
C1, C2, C5 1uF (labeled 105)
C3, C4 18pF (labeled 180)
D1 1N4148
  2x Slide switch
  LCD headers
IC1 7805
IC2 ATMega328
IC3 4N25
IC4 74HC4050
IC5 3.3V regulator (note that early boards are mislabeled)
Y1 16MHz crystal
  Fiber optic transmitter
  2x CR123A battery holder
J2 MIDI jack
S1, S2, S3 Tall tactile switch


Heat up your iron! Let’s start soldering. We’ll begin with the SD card interrupter because we need it working to test the Tesla coil’s electronics later on.

  • A. Install resistors R1 through R10. Note that in early boards, R9 is mislabeled as 1kΩ and should be 100Ω (see image below)!
  • B. Install capacitors C1 through C5.
  • C. Install sockets for IC2, IC3, and IC4. Align the notch on the socket to the notch pictured on the board.
  • D. Install D1 and D2.
  • E. Install the slide switches.
  • F. Install the 16-pin female header for the LCD.
  • G. Install IC1 (a 78L05 5V regulator) and IC5 (a 3.3 V regulator). See image.
  • H. Install 16MHz crystal Y1.
  • I. Install the optical transmitter.
  • J. Install the two CR123A battery holders. Ensure that the + mark on each socket aligns with the + mark on the board!
  • K. Install J2, the MIDI jack.
  • L. Install the tall pushbutton switches S1, S2, and S3.
  • M. Install the ICs in their sockets, taking care to orient them correctly.
  • N. Solder the male header pins into the LCD module.
  • O. Place the LCD module into the female header pins on the board. You don’t need to install the standoffs yet, as you should confirm that the board works before finishing the mechanical assembly.
  • P. Install the batteries, taking care to orient them correctly.


SD interrupter diagram     LCD Module

Step N



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