Introduction
This is a tutorial on how to assemble the MIDI Bastl Kit.
Kit Components (Without Sync)
- PCB board
- 8 pin socket for IC
- IC: 6N137 - optoisolator
- 20 pin header
- 2x female right angle 4-pin header (or longer one to cut)
- Electrolytic capacitor 10uF
- 4148 diode
- 3 x 220 ohm resistors
- MIDI jack
- 78L05 voltage regulator
- 6 jumpers
- 4 round screws
- 4 flat screws
- 4 small spacers
- 4 long spacers
- Top plexi board
- Bottom plexi board
- 2 side plexi boards
- Front plexi board
- Rear plexi board
- Hexagon screwdriver
- Manual
Sync Kit Components
- 8 pin socket
- IC: pre-programmed Attiny 85
- Pin header
- Jumpers
- 3.5mm TRS stereo Jack
Step 1: Prepare the 4-pin Angle Female Headers
This step involves preparing two 4-pin angled female pin headers. Cut them in the middle of a pin, not between pins. Ensure accurate measurement and check reference photos. After cutting, trim the remaining plastic to ensure the headers fit snugly into the plastic housing.
Visual Description: A 10-pin header is shown with markings indicating cuts at pin 4. Pliers are used to make these cuts, separating the header into two 4-pin sections. The plastic is then trimmed.
Step 2: Solder the 4-pin Headers
Begin soldering. All components are soldered from the component side of the PCB, which is marked with component labels. Place the prepared 4-pin headers and solder them, ensuring they are straight.
Visual Description: The PCB is shown with two 4-pin headers being soldered from the component side. The headers are positioned correctly on the board.
Step 3: Solder Diode and Resistors
Bend the legs of the 1N4148 diode and place it according to the diagram. The stripe on the diode (typically black) corresponds to the stripe (often white) on the PCB print, indicating polarity. Solder the diode and three 220-ohm resistors. Ensure correct polarity for the diode and capacitor.
Visual Description: A 1N4148 diode with a black stripe and three 220-ohm resistors are shown. The PCB is depicted with the diode and resistors soldered in place, respecting the diode's stripe polarity. Another image shows the soldering process with a soldering iron and cutters trimming excess leads.
Step 4: Solder the 8-pin Socket
Place the 8-pin socket onto the PCB. Ensure the socket's polarity is observed; the notch typically faces upwards. This orientation is important for correctly inserting ICs later.
Visual Description: The PCB is shown with the 8-pin socket soldered into place. The notch on the socket is visible and oriented upwards.
Step 5: Solder the Sync Jack
Solder the sync jack, used for sync out. Ensure the jack is seated fully against the PCB, with no gap between the connector and the board.
Visual Description: The PCB is shown with the 3.5mm stereo jack soldered. The jack is flush with the board surface.
Step 6: Solder Voltage Regulator and Capacitor
Place the voltage regulator (78L05) and the 10uF electrolytic capacitor. Pay close attention to polarity. The capacitor's shorter leg (negative terminal) should be closer to the pin header. Note that space can be tight, but this does not affect functionality.
Visual Description: The PCB is shown with the voltage regulator and electrolytic capacitor soldered. The capacitor's polarity is indicated by the shorter leg being positioned correctly.
Step 7: Prepare and Solder Pin Headers for Jumpers
Prepare eight 3-pin headers. To facilitate soldering, use jumper connectors to hold the six pins together. After soldering, remove the jumpers; they will be set later.
Visual Description: Several 3-pin headers are shown, some held together by jumper caps. The PCB is shown with these headers soldered in place, ready for jumpers.
Step 8: Prepare and Solder the MIDI Jack
If the MIDI jack has excess plastic ('left-overs'), trim them off. Solder the connector to the PCB, ensuring a flush fit with no gap.
Visual Description: A MIDI jack is shown being trimmed with pliers to remove excess plastic. The jack is then soldered onto the PCB.
Step 9: Insert the ICs
Insert the ICs (6N137 optoisolator and Attiny85 microcontroller) into their respective sockets. The polarity of each IC is indicated by a small dot or notch in one corner. Align this marking with the corresponding marking on the socket or PCB. The IC legs may need slight bending to fit into the socket.
Visual Description: Two ICs, labeled 6N137 and ATTINY85, are shown. The PCB with sockets is depicted, and the ICs are being placed into the sockets, with attention to the polarity indicator (dot/notch).
Step 10: Configure Jumpers
Configure the jumpers based on desired functionality. For MIDI input, place jumpers as shown in the 'MIDI IN' picture. For MIDI output, follow the 'MIDI OUT' configuration.
Visual Description: Two configurations for jumpers are shown on the PCB. One shows jumpers set for 'MIDI IN' and the other for 'MIDI OUT'.
Step 11: Install Spacers and Assemble Housing
Install the spacers correctly and screw them in tightly. For the sync part, where space is limited, first place the long spacer, then screw in the short one from the opposite side. This ensures proper alignment.
Visual Description: The PCB assembly with soldered components is shown. Various plastic housing parts (top, bottom, front, rear, sides) and screws are laid out. The process of assembling the plastic enclosure around the PCB using screws and spacers is depicted in a series of images.
Step 12: Test the Assembly
Before fully enclosing the MIDI Bastl, it is recommended to test its functionality. Refer to the manufacturer's manual for specific testing procedures.
Step 13: Final Assembly and Enjoy
Congratulations on successfully assembling your MIDI Bastl! Now, enclose the assembled unit within the plastic housing. Ensure side connectors are properly soldered for a neat fit. Enjoy your new MIDI device [heart].
Visual Description: The final assembled MIDI Bastl unit is shown, enclosed in its plastic casing. The process of fitting the PCB into the housing and securing it with screws is illustrated.
