Velvet74
About the Velvet74 PCB
Velvet74 is an open source RP2040/RP2350 PCB design by unseensnick, published on GitHub under the MIT license. It is a 4-layer board measuring 268 × 133.3 mm, with 312 components from 24 distinct parts.
Its main chip is the RP2040, from the RP2040/RP2350 family. Other key parts include the USBLC6-2P6, ZD25Q128CWIGR, AP2112K-3.3TRG1 and SN74LV1T34DBVR. By type, the board carries 114 capacitors, 78 diodes, 74 LEDs, 20 resistors, 12 ICs and 4 connectors.
It belongs with the keyboards and displays & leds designs in this gallery.
From the project
A 74-key split keyboard with Choc switches and a chip-down RP2040 on each half, in the Sofle layout. Key positions, the board outline and the case come from Ergogen; parts, nets and fabrication data live in a KiCad 10 project aimed at JLCPCB assembly.
A 74-key split keyboard with Choc switches and a chip-down RP2040 on each half, in the Sofle layout. Key positions, the board outline and the case come from Ergogen; parts, nets and fabrication data live in a KiCad 10 project aimed at JLCPCB assembly.
One 4-layer board, 268 x 118 mm before the panel rails, holds both halves 10 mm apart. Each half has 37 keys: a 6 x 5 matrix, 5 thumb keys and 2 EC11 encoders that double as keys, each with an SK6812MINI-E under it.
Main components on the Velvet74
Velvet74 bill of materials (BOM)
312 components, 24 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 2 | RP2040 Raspberry Pi | QFN-56-1EP_7x7mm_P0.4mm_EP3.2x3.2mm_ThermalVias | U1, U201 |
| 4 | USBLC6-2P6 R+O | SOT-563_USBLC6-2P6 | U2, U4, U202, U204 |
| 2 | ZD25Q128CWIGR Zetta | WSON-8-1EP_6x5mm_P1.27mm_EP3.4x4mm | U3, U203 |
| 2 | AP2112K-3.3TRG1 AP2112K-3.3 Diodes Inc | SOT-23-5_L3.0-W1.7-P0.95-LS2.8-BL | U5, U205 |
| 2 | SN74LV1T34DBVR Texas Instruments | SOT-23-5 | U6, U206 |
| 2 | ABM8-272-T3 Abracon LLC | CRYSTAL-SMD_4P-L3.2-W2.5-BL | X1, X201 |
| 4 | HC-TYPE-C-16P-C16B Connector, USB-TYPE-C-16P HongCheng | USB_C_Receptacle_HongCheng_HC-TYPE-C-16P_MidMount | J1, J2, J201, J202 |
| 4 | 1206L110THYR 1.1A Littelfuse | Fuse_1206_3216Metric | F1, F2, F201, F202 |
| 2 | TS-1088-AR02016 BOOT XUNPU | SW_Push_1P1T_XUNPU_TS-1088-AR02016 | SW1, SW201 |
| 2 | TS-1088-AR02016 RESET XUNPU | SW_Push_1P1T_XUNPU_TS-1088-AR02016 | SW2, SW202 |
| 74 | SK6812MINI-E OPSCO(欧思科) | LED-SMD_4P-L3.2-W2.8-LS5.9_SK6812MINI-E | LED10, LED11, LED12, LED13, LED14, LED15, LED16, LED20 +66 |
| 2 | B5819W SL Changjiang Electronics Tech (CJ) | D_SOD-123 | D1, D201 |
| 2 | SMF5.0A hongjiacheng | D_SOD-123FL | D2, D202 |
| 74 | 1N4148W ST(Semtech) | D_SOD-123 | D10, D11, D12, D13, D14, D15, D16, D20 +66 |
| 4 | 0402CG150J500NT 15pF FH(Guangdong Fenghua Advanced Tech) | C_0402 | C1, C4, C201, C204 |
| 98 | CL05B104KO5NNNC 100nF Samsung Electro-Mechanics | C_0402 | C3, C5, C6, C10, C11, C12, C13, C14 +90 |
| 8 | CL05A105KA5NQNC 1uF Samsung Electro-Mechanics | C_0402 | C7, C8, C19, C20, C207, C208, C219, C220 |
| 4 | CL10A106KP8NNNC 10uF Samsung Electro-Mechanics | C_0603 | C9, C18, C209, C218 |
| 4 | 0402WGF1001TCE 1kΩ UNI-ROYAL(Uniroyal Elec) | R_0402 | R2, R4, R202, R204 |
| 4 | 0402WGF5101TCE 5.1kΩ UNI-ROYAL(Uniroyal Elec) | R_0402 | R5, R6, R205, R206 |
Show 4 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 4 | 0402WGF270JTCE 27Ω UNI-ROYAL(Uniroyal Elec) | R_0402 | R7, R8, R207, R208 |
| 4 | 0402WGF1002TCE 10kΩ UNI-ROYAL(Uniroyal Elec) | R_0402 | R10, R11, R210, R211 |
| 2 | 0402WGF4700TCE 470Ω UNI-ROYAL(Uniroyal Elec) | R_0402 | R15, R215 |
| 2 | 0402WGF1200TCE 120Ω UNI-ROYAL(Uniroyal Elec) | R_0402 | R16, R216 |
Velvet74 design files
The KiCad project lives in the unseensnick/Velvet74 repository on GitHub; these links point at the commit this page was built from.
- Layoutvelvet74.kicad_pcb
- Schematicvelvet74.kicad_sch
- BOMproduction/pcbway/bom.csv
Velvet74: common questions
What microcontroller does the Velvet74 use?
The Velvet74 is built around the RP2040, from the RP2040/RP2350 family.
How big is the Velvet74 PCB?
The Velvet74 measures 268 × 133.3 mm, has 4 copper layers and is 1.6 mm thick.
How many components are on the Velvet74?
312 components, from 24 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.
Where can I download the Velvet74 design files?
From the unseensnick/Velvet74 repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.
Can I use the Velvet74 design in my own project?
Yes, under the terms of its MIT license, which unseensnick chose for the repository.
Can I test firmware for the Velvet74 without the hardware?
Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug RP2040/RP2350 firmware against it before you order a PCB.
More boards in Velvet74
Similar boards
RP2040/RP2350Open Book Abridged Edition
joeycastillo
85 × 115 mm29 parts2LCC-BY-SA-4.08.1k
RP2040/RP2350Corne
foostan
277.2 × 107.5 mm164 parts2LCC-BY-4.07.7k
RP2040/RP2350Corne
277.2 × 107.5 mm164 parts2LCC-BY-4.07.7k
RP2040/RP2350LogicAnalyzer
gusmanb
57 × 55.2 mm6 parts2LGPL-3.05.0k
RP2040/RP2350Jitx design
55.5 × 65 mm26 parts4LGPL-3.05.0k
RP2040/RP2350Pro V2
kata0510
290.1 × 130 mm270 parts2LMIT2.3k