4 layers99 × 53.3 mm
PSLab
fossasia/pslab-hardware
PSLab Hardware Design and Schematics https://pslab.io
199 parts1.7kApache-2.0
2 layers98.1 × 54.8 mm
TrlPad
TrlRizu/TrlPadA macropad with an OLED display
- Size
- 98.1 × 54.8 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 16
- Nets
- 26
- Pads
- 69
- Tracks, vias
- 104, 8
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 10 Oct 2025
- Updated
- 7 Nov 2025
Overview
TrlPad is an open-source printed circuit board by TrlRizu, from the TrlRizu/TrlPad repository on GitHub. It is a 2-layer board of 98.1 × 54.8 mm with 16 parts on 26 nets, routed with 104 tracks and 8 vias.
It is built around the 1N4148W. Its parts include 5 diodes, 5 switches, 2 resistors and 2 ICs. It belongs with the keyboards and input and lEDs and displays boards and the nRF52 and nRF5x boards of this library.
Main components
1README
README.mdTrlPad
TrlPad is a 4-key macropad with a rotary encoder, an OLED display.
Features
- 4 programmable mechanical keys (MX-style switches)
- Rotary encoder with push-button for multi-function input
- 0.91" 128x32 OLED dispvlay (SSD1306)
- Powered by Seeed Studio XIAO nRF52840 (Bluetooth + USB)
- Custom PCB
How it evolved
The initial concept
The design concept was to be something akin to a pedal effect. A sketch of what I thought it'd be:
Final
Yeah, it's rather different but this is more feasible and it's simple yet punk-y.
PCB
Below is the schematic:
Below is the PCB routing:
Bill of Materials (BOM)
| # | Reference | Value | Footprint | Qty | Link | Price (USD) | Running Price (USD) |
|---|---|---|---|---|---|---|---|
| 1 | D1, D2, D3, D4 | D | Diode_THT:D_DO-35_SOD27_P7.62mm_Horizontal | 4 | AliExpress | 1.41 | 1.41 |
| 2 | D5 | 1N4148W | Diode_SMD:D_SOD-123 | 1 | AliExpress | 1.95 | 3.36 |
| 3 | R1 | 806k | Resistor_SMD:R_0805_2012Metric | 1 | AliExpress | 0.66 | 4.50 |
| 4 | R2 | 2M | Resistor_SMD:R_0805_2012Metric | 1 | AliExpress | 0.48 | 4.50 |
| 5 | SW1, SW2, SW3, SW4 | SW_Push | Button_Switch_Keyboard:SW_Cherry_MX_1.00u_PCB | 4 | AliExpress | 1.01 | 5.51 |
| 6 | SW5 | RotaryEncoder_Switch | Rotary_Encoder:RotaryEncoder_Alps_EC11E-Switch_Vertical_H20mm | 1 | AliExpress | 0.63 | 6.14 |
| 7 | TP1, TP2 | TestPoint | TestPoint:TestPoint_Pad_D2.0mm | 2 | — | — | 6.14 |
| 8 | U1 | XIAO-nRF52840-SMD | Modified:modified-XIAO-nRF52840-SMD | 1 | AliExpress | 10.11 | 16.25 |
| 9 | U2 | 128x32_OLED_S | zzz_Project:SSD1306-0.91-OLED-4pin-128x32 | 1 | AliExpress | 2.24 | 18.49 |
| 10 | Shipping costs | — | for AliExpress check cart.png | — | — | 3.05 | 21.54 |
| 11 | 3D Printed case | — | check screenshot 3dCase_bill.png | — | 3Ding | 16.29 | 37.83 |
| 12 | PCB | — | from JLPCB, check screenshot jlcpcb.png | — | — | 7.56 | 45.39 |
Total Estimated Cost: 45.39 USD
Note: I am trying to get the case 3D printed using #printing-legion, or if that doesn't work out, I'll cover the cost on my own!
Parts
16| Qty | Value | Footprint | References |
|---|---|---|---|
| 4 | D | Diode_THT:D_DO-35_SOD27_P7.62mm_Horizontal | D1, D2, D3, D4 |
| 4 | SW_Push | Button_Switch_Keyboard:SW_Cherry_MX_1.00u_PCB | SW1, SW2, SW3, SW4 |
| 2 | TestPoint | TestPoint:TestPoint_Pad_D2.0mm | TP1, TP2 |
| 1 | 128x32_OLED_S | zzz_Project:SSD1306-0.91-OLED-4pin-128x32 | U2 |
| 1 | 1N4148W | Diode_SMD:D_SOD-123 | D5 |
| 1 | 2M | Resistor_SMD:R_0805_2012Metric | R2 |
| 1 | 806k | Resistor_SMD:R_0805_2012Metric | R1 |
| 1 | RotaryEncoder_Switch | Rotary_Encoder:RotaryEncoder_Alps_EC11E-Switch_Vertical_H20mm | SW5 |
| 1 | XIAO-nRF52840-SMD | Modified:modified-XIAO-nRF52840-SMD | U1 |
Questions
How big is the TrlPad PCB?
It measures 98.1 × 54.8 mm and has 2 copper layers, 1.6 mm thick.
What parts does the TrlPad use?
16 parts, built around the 1N4148W. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the TrlPad KiCad files?
From the TrlRizu/TrlPad repository on GitHub, at the commit this page was made from: the board is PCB/TrlPad.kicad_pcb and its schematic PCB/TrlPad.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the TrlPad design in my own project?
Its repository states no licence, so its author keeps all rights: ask TrlRizu before reusing the design.
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