TrlPad is a 4-key macropad with a rotary encoder, an OLED display.
- 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
The design concept was to be something akin to a pedal effect. A sketch of what I thought it'd be:
Yeah, it's rather different but this is more feasible and it's simple yet punk-y.
Below is the schematic:
Below is the PCB routing:
| # | 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