Mathpad

mithralcode·mathpad·PCB/macropad.kicad_pcb

About the Mathpad PCB

Mathpad is an open source RP2040/RP2350 PCB design by mithralcode, published on GitHub under the MIT license. It is a 2-layer board measuring 81 × 98.6 mm, with 50 components from 5 distinct parts.

Its main chip is the XIAO-RP2040-DIP, from the RP2040/RP2350 family. By type, the board carries 32 diodes, 16 switches and 2 ICs.

It belongs with the displays & leds and keyboards designs in this gallery.

From the project

A 4x4 Macro-pad with OLED Display and per key addressable LEDs.

MathPad is a compact 4x4 mechanical keypad designed for fast numeric and math input. Its primary purpose is to provide a customizable keypad for productivity, coding, or creative projects. The keyboard features a Seeed XIAO RP2040 microcontroller, fully programmable firmware via KMK, and a small OLED display for dynamic feedback or animations.

- Test the board before assembling the case - Be cautious with LED soldering

Mathpad, from the project README — From the project README

Main components on the Mathpad

XIAO-RP2040-DIP

Mathpad bill of materials (BOM)

50 components, 5 distinct parts.

Qty	Part	Footprint	Refs
1	XIAO-RP2040-DIP	XIAO-RP2040-DIP	U1
1	~	SSD1306-0.91-OLED-4pin-128x32	U2
16	SW_Push	SW_Cherry_MX_1.00u_PCB	SW1, SW2, SW3, SW4, SW5, SW6, SW7, SW8 +8
16	1N4148	D_DO-35_SOD27_P7.62mm_Horizontal	D1, D2, D3, D4, D5, D6, D7, D8 +8
16	SK6812MINI-E	MX_SK6812MINI-E_REV	D17, D18, D19, D20, D21, D22, D23, D24 +8

Mathpad design files

The KiCad project lives in the mithralcode/mathpad repository on GitHub; these links point at the commit this page was built from.

LayoutPCB/macropad.kicad_pcb
SchematicPCB/macropad.kicad_sch

Mathpad: common questions

What microcontroller does the Mathpad use?

The Mathpad is built around the XIAO-RP2040-DIP, from the RP2040/RP2350 family.

How big is the Mathpad PCB?

The Mathpad measures 81 × 98.6 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Mathpad?

50 components, from 5 distinct parts. The full bill of materials is listed on this page.

Where can I download the Mathpad design files?

From the mithralcode/mathpad repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the Mathpad design in my own project?

Yes, under the terms of its MIT license, which mithralcode chose for the repository.

Can I test firmware for the Mathpad 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.