4 layers101.9 × 75.4 mm
2 layers18 × 33.2 mm
Pro smolcro
extinct00/pro_smolcroRP2040 dev board for my keyboards
- Size
- 18 × 33.2 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 32
- Nets
- 55
- Pads
- 177
- Tracks, vias
- 455, 57
- Pours
- 24
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 7 Mar 2025
- Updated
- 12 Mar 2025
Overview
Pro smolcro is an open-source printed circuit board by extinct00, from the extinct00/pro_smolcro repository on GitHub. It is a 2-layer board of 18 × 33.2 mm with 32 parts on 55 nets, routed with 455 tracks and 57 vias.
It is built around the RP2040, W25Q128JVSIQ and TLV75733PDBV, with the ABM8-272-T3 among its other parts. Its parts include 15 capacitors, 6 resistors, 4 connectors, 3 ICs and 1 diode. It belongs with the RP2040 boards of this library.
Main components
4
RP2040
LQFN-56(7x7)12bit 133MHz 30 LQFN-56(7x7) Microcontrollers (MCU/MPU/SOC) ROHSRaspberry PiMicrocontrollers (MCU/MPU/SOC)
W25Q128JVSIQ
SOIC-8-208mil-40℃~+85℃ 100,000 cycles 120ms@(32KB) 128Mbit 133MHz 1uA 2.7V~3.6V 20 Years 3ms Power-on reset、Hardware write protection、Software write protection、Write enable latch、Absolute write protection SPI SOIC-8-208mil NOR FLASH ROHSWinbondNOR FLASH
TLV75733PDBV
SOT-23-5-40℃~+125℃@(Tj) 1 1A 3.3V 40uA 46dB@(100kHz) 5.5V 650mV@(1A) 71.5uVrms Fixed Positive Under Voltage Lockout、Over Current Protection、Over Temperature Protection、Soft Start SOT-23-5 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSTexas InstrumentsVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
ABM8-272-T3
SMD3225-4P-40℃~+85℃ 10pF 12MHz 50Ω SMD crystal oscillator ±30ppm ±30ppm SMD3225-4P Crystals ROHSAbraconCrystals
README
README.mdpro_smolcro
Some requirements for this board:
- Should be a replacement for a pro micro, therefore have the same pinout and should have the same dimensions
- Have a 5V out from the usb that could be used to either power the other microcontroller or to power some 5v LEDs for better efficiency
- RP2040 based board with 16MB of flash memory
- Look into how to detect VUSB from QMK, so i can make sure it works
Parts
32| Qty | Value | Footprint | References |
|---|---|---|---|
| 9 | 100n | Capacitor_SMD:C_0402_1005Metric | C3, C4, C5, C6, C7, C8, C9, C10, C13 |
| 4 | 1u | Capacitor_SMD:C_0603_1608Metric | C1, C2, C11, C12 |
| 2 | 15p | Capacitor_SMD:C_0402_1005Metric | C14, C15 |
| 2 | 27.4 | Resistor_SMD:R_0402_1005Metric | R3, R4 |
| 2 | 5.1k | Resistor_SMD:R_0402_1005Metric | R1, R2 |
| 2 | Conn_01x13 | Connector_PinSocket_2.54mm:PinSocket_1x13_P2.54mm_Vertical | J3, J4 |
| 2 | TestPoint | TestPoint:TestPoint_Pad_1.0x1.0mm | TP4, TP5 |
| 1 | 1k | Resistor_SMD:R_0402_1005Metric | R7 |
| 1 | 68R | Resistor_SMD:R_0402_1005Metric | R8 |
| 1 | ABM8-272-T3 | Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm | Y1 |
| 1 | Conn_01x05 | Connector_PinSocket_2.54mm:PinSocket_1x05_P2.54mm_Vertical | J2 |
| 1 | LED | LED_SMD:LED_0402_1005Metric | D4 |
| 1 | RP2040 | Package_DFN_QFN:QFN-56-1EP_7x7mm_P0.4mm_EP3.2x3.2mm | U1 |
| 1 | SHOU HAN TYPE-C 16PIN 2MD(073) | Connector_USB:USB_C_Receptacle_G-Switch_GT-USB-7010ASV | J1 |
| 1 | TLV75733PDBV | Package_TO_SOT_SMD:SOT-23-5 | U4 |
| 1 | W25Q128JVS | Package_SO:SOIC-8_5.3x5.3mm_P1.27mm | U3 |
Questions
How big is the Pro smolcro PCB?
It measures 18 × 33.2 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Pro smolcro use?
32 parts, built around the RP2040, W25Q128JVSIQ, TLV75733PDBV and ABM8-272-T3. 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 Pro smolcro KiCad files?
From the extinct00/pro_smolcro repository on GitHub, at the commit this page was made from: the board is Pro_Smolcro/Pro_Smolcro.kicad_pcb and its schematic Pro_Smolcro/Pro_Smolcro.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Pro smolcro design in my own project?
Its repository states no licence, so its author keeps all rights: ask extinct00 before reusing the design.
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