Build Guide¶
This build guide assumes the reader has some experience with building open-source electronics kits.
The PCBs have been designed with partial assembly from JLCPCB in mind. Hand soldering through-hole components will be required once ordered PCBs arrive.
It's recommended to have access to a 3D printer. Some of the parts are designed to be 3D printed, such as the case and button caps. Optionally a 3D printing service such as JLC3DP could be used.
Part Ordering¶
All parts required to populate the PCBs can be purchased from LCSC/JLCPCB with the following exceptions:
- Transformers - Usually in stock at Mouser.
- Potentiometers - Available at Mouser. Available as a preorder item at LCSC at the time of writing.
- Rotary Encoders - Available at Mouser. Out of stock at LCSC at the time of writing.
BOM lists are available with associated zipped gerber files located in the /pcb directory. Each list is split in two, one for the surface mount components intended for the JLCPCB assembly service (*.bom.csv), and another for through-hole components (*.bom-hand_assembly.csv).
This allows for easy ordering of through-hole components at LCSC via their BOM Tool.
Misc Parts¶
Parts that don't fit the assembly BOM files are placed in the BOM file located in the /docs/assets directory.
| Name | Description | Supplier | Quantity | Notes |
|---|---|---|---|---|
| Display | 1.8 Color TFT SPI Display (ADA358) | Adafruit | 1 | Search for ADA358 for resellers |
| Case | 3D Printed Case | User or Print Service | 1 | nan |
| Button Caps | 3D Printed Button Caps 10x10 | User or Print Service | 4 | nan |
| Power Button Cap | 3D Printed Button Cap 7x7 | User or Print Service | 1 | nan |
| Ribbon Cable | 2x4 16P 2.54mm 0.1” Pitch Ribbon Cable | Amazon/AliExpress | 1 | Connects main_board to front_panel_control |
| Jumper Cable | 1x10 2.54mm 0.1” Pitch Jumper Cable | Amazon/AliExpress | 1 | Connects front_panel_control to display module |
| Encoder/Pot Knobs | Rotary Encoder & Potentiometer Knobs | Amazon/AliExpress | 5 | Knurled 18T - Min ~8 mm depth |
| Display Standoffs | M2 Nylon Standoffs + Screws/Nuts | Amazon/AliExpress | 4 | 6mm length (with foam under display) or M2 spacers (~3mm length) |
| Front Panel Standoffs | M2 Nylon Standoffs + Screws/Nuts | Amazon/AliExpress | 5 | 10mm length |
| U.FL Antenna | 2.4 GHz U.FL Antenna | Amazon/AliExpress | 1 | Internal Omnidirectional PCB antenna – 50 ohm |
PCB Ordering¶
The following provides recommended settings for ordering PCBs and getting them assembled. If an option isn't specified it's assumed to be set to the default setting provided by JLCPCB.
Component rotations in CPL files should be correct, but I recommend to double check them anyway during checkout.
About order quantity
Please note that the minimum order quantity for PCB Assembly at JLCPCB is two, while the minimum for PCB fabrication is five. Additionally certain components have a minimum assembly quantity of five (and attrition quantity but we will ignore that for now).
If you order two assembled boards each using one component, and this component has a minimum assembly quantity of five, it will still use five components. You then will receive two assembled and three blank PCBs.
Additionally initial setup fees don't scale with order quantity, so ordering five is more efficient than ordering two assembled boards.
Main Board¶
| Asset | File |
|---|---|
| Gerbers | main_board.zip |
| BOM | main_board.bom.csv |
| CPL | main_board.top-cpl.csv |
| Option | Value |
|---|---|
| Base Material | FR-4 |
| Layers | 4 |
| PCB Thickness | 1.6mm |
| Outer Copper Weight | 1oz |
| Inner Copper Weight | 0.5oz |
| Specify Layer Sequence | F_Cu, In1_Cu, In2_Cu, B_Cu |
| Impedance Control? | Yes |
| Layer Stackup | JLC04161H-7628 |
| Via Covering | Plugged (free upgrade from tented) |
| Remove Order Number | Specify a location |
| PCB Assembly? | Yes |
|---|---|
| PCBA Type | Economic |
| Assembly Side | Top Side |
Output Board¶
| Asset | File |
|---|---|
| Gerbers | output_board.zip |
| BOM | output_board.bom.csv |
| CPL | output_board.top-cpl.csv |
| PCB Option | Value |
|---|---|
| Base Material | FR-4 |
| Layers | 2 |
| PCB Thickness | 1.6mm |
| Outer Copper Weight | 1oz |
| Via Covering | Tented |
| Remove Order Number | Specify a location |
| PCB Assembly? | Yes |
|---|---|
| PCBA Type | Economic |
| Assembly Side | Top Side |
Front Control Board¶
| Asset | File |
|---|---|
| Gerbers | front_control_board.zip |
| BOM | front_control_board.bom.csv |
| CPL | front_control_board.top-cpl.csv |
| Option | Value |
|---|---|
| Base Material | FR-4 |
| Layers | 2 |
| PCB Thickness | 1.6mm |
| Outer Copper Weight | 1oz |
| Via Covering | Tented |
| Remove Order Number | Specify a location |
| PCB Assembly? | Yes |
|---|---|
| PCBA Type | Standard (required for LEDs and ESP32 module) |
| Assembly Side | Top Side |
| Bake Components? | Yes (recommended for moisture sensitive LEDs. LEDs have a high chance of being DOA without this) |
Front Panel¶
| Asset | File |
|---|---|
| Gerbers | front_panel.zip |
| BOM | N/A |
| CPL | N/A |
| Option | Value |
|---|---|
| Base Material | FR-4 |
| Layers | 2 |
| PCB Thickness | 1.6mm |
| Outer Copper Weight | 1oz |
| Via Covering | Tented |
| PCB Color | Black (suggested for high contrast readable text, feel free to pick any color) |
| Silkscreen | White |
| Remove Order Number | Specify a location |
| PCB Assembly? | No |
|---|---|
| Front panel has no components | . |
Assembly¶
View the iBOM (*-ibom.html) for an overview and guidance on component placement. Use HandAssembly as the filter to show only the components needing hand soldering.
See the *.bom-hand_assembly.csv and bom.misc.csv BOM files for the parts list of components requiring manual assembly.
The sections listed below are in recommended assembly order.
Front Control Board¶
Image of board as it arrived from JLCPCB:
- Remove assembly rails by bending along v-cut lines, being careful not to bend the PCB near any of the components.
- Hand solder through-hole components on the sides indicated by the silkscreen.
- BZ1 can be installed on the bottom side, or top side if using 10mm standoffs.
- J4 is optional and only needed if you want to add extra LED strips.
- Recommended to solder back components first (J1, J2, and J3) and optionally J4/BZ1.
- Install 5x standoffs on top side of board.
- Attach the U.FL antenna to the connector on the ESP32 module (U1).
Fully assembled board:
Front Panel¶
Image of board as it arrived from JLCPCB:
- Ensure the display module has a 10P 0.1" pin header soldered on the back.
- Install 4x display standoffs onto display module first, then attach to the front panel with 4x screws.
- Place 4x 10x10 button caps into the holes of the front panel board.
- Install front panel control board onto front panel with 4x screws, so the button caps are captured between the two PCBs.
- Push on the encoder/pot knobs.
Fully assembled board:
Main Board¶
Image of board as it arrived from JLCPCB:
- Hand solder through-hole components on the top side (indicated by the silkscreen).
- Recommended to solder SW1 first, then CT1, CT2, CT3, and CT4.
- J7/J8 are optional and only used for debugging and future peripheral addon support.
- Ensure TRS sockets (J15-J18, J2-J3, J9, J11) are aligned with the board edge before soldering, so the front panel will fit cleanly.
Fully assembled board:
Output Board¶
Image of board as it arrived from JLCPCB:
- Hand solder through-hole components on the sides indicated by the silkscreen.
- Recommended to solder back components first (J1, J2, and J3), ensure they are aligned correctly by first plugging them into the main board.
- The "P" marking on each transformer (T1, T2, T3, and T4) should face towards J3 (CH_OUT). We are using the transformers in reverse, the primaries going to outputs.
- The 4x MOSFETs (Q1, Q4, Q7, and Q10) should have the exposed metal pad facing towards the transformers.
MOSFET Metal Pads
Ensure that the exposed metal pads of each MOSFET (Q1, Q4, Q7, and Q10) are not touching one another. Recommend to solder one leg of each MOSFET first, so the spacing/clearance can be adjusted easily, before soldering the remaining legs. A high-temp non-conductive separator between each pad might also be a wise addition (e.g. polyimide tape).
Vibration
If the box is going to be subjected to vibrations, securing the MOSFETs to the PCB is also recommended. This will prevent the legs from breaking due to metal fatigue.
Fully assembled board:
Main Board assembly:
Case¶
TBW