dpx_biz Quickstart

About

hello world.i am a normal businessman, currently conducting business

A pocket-sized RP2040 board with 12 capacitive touch pads and 10 addressable RGB LEDs. This repo ships two tiny example firmwares // pick one, they're separate builds. No config files, no mode switching, no USB storage. Just enough to prove the hardware works and give you a clean file to start hacking from.

env: midi_demo

MIDI demo

Touch a pad → its LED lights up → a MIDI note fires over USB.

pio run -e midi_demo -t upload

One fixed note per pad // chromatic run from C4
Note on touch-start, note off on release
Open any MIDI monitor or DAW to see it

test it live // dpx_biz_synth →

env: hid_demo

HID demo

Touch a pad → its LED lights up → a keypress fires over USB.

pio run -e hid_demo -t upload

Same shortcuts the production firmware ships with, for disguise d3 designer show control
Layer/section navigation, e.g. pad 0 = ctrl+alt+↑ layer up
Key held down while the pad is touched

test it live // dpx_biz_hid →

Reference

Pinout & hardware

Hover a pad on the board to see its GPIO, LED index, and what the two demos send when you touch it.

dpx_biz PCB, front side, showing 12 capacitive touch pads

pad 0 · x.1

gpio3

led0

midinote 60

hidctrl+alt+↑

d3layer up

pad 1 · x.2

gpio2

led1

midinote 61

hidalt+s

d3split section

pad 2 · x.3

gpio1

led2

midinote 62

hidalt+m

d3merge section

pad 3 · x.4

gpio4

led3

midinote 63

hidctrl+alt+[

d3trim to playhead

pad 4 · x.5

gpio9

led4

midinote 64

hido

d3end of container

pad 5 · x.6

gpio7

led9

midinote 65

hid.

d3next section

pad 6 · x.7

gpio6

led8

midinote 66

hid,

d3previous section

pad 7 · x.8

gpio5

led7

midinote 67

hidalt+t

d3repeat prev tag

pad 8 · x.9

gpio10

led6

midinote 68

hidspace

d3play section

pad 9 · x.10

gpio11

led5

midinote 69

hidctrl+alt+↓

d3layer down

SW1 · boot

pressreset/reboot

SW2 · reset

hold at power-upbootloader

D1 · status LED

blinkheartbeat

USB

USB-C port

notetop edge, right side

pad 10 · no LED

noteon the QR code

pad 11 · no LED

noteon the dubpixel logo

hover / tap a marker // numbers match the pad index used in the firmware (0-indexed)

pad	silk	gpio	led	midi	hid	d3 function
0	x.1	3	0	60	ctrl+alt+↑	layer up
1	x.2	2	1	61	alt+s	split section
2	x.3	1	2	62	alt+m	merge section
3	x.4	4	3	63	ctrl+alt+[	trim to playhead
4	x.5	9	4	64	o	end of container
5	x.6	7	9	65	.	next section
6	x.7	6	8	66	,	previous section
7	x.8	5	7	67	alt+t	repeat prev tag
8	x.9	10	6	68	space	play section
9	x.10	11	5	69	ctrl+alt+↓	layer down
10	-	18	none	70	esc	escape
11	-	19	none	71	tab	tab

The HID demo ships the same shortcuts the production firmware uses for disguise d3 designer // layer and section navigation for show control.

Pads 10 & 11 aren't silkscreened with a number and have no LED beneath them, so they're left off the board diagram // both sit along the bottom edge near center.

Other pins: WS2812 data → GPIO 0 · onboard status LED (D1) → GPIO 25.

Getting started

Build & flash

Install PlatformIO

CLI or the VS Code extension // platformio.org

Clone & open

git clone https://github.com/dubpixel/dpx_biz_qwikstrt
cd dpx_biz_qwikstrt/firmware/src/current/dpx_biz_qwikstrt

Build your pick

pio run -e midi_demo # or -e hid_demo

Enter the bootloader

Hold RESET (top-right, near USB) → while holding, press BOOT (bottom edge) → release both. Board appears as the RPI-RP2 USB drive.

Flash

Drag the built .pio/build/<env>/firmware.uf2 onto the RPI-RP2 drive. It reboots into your new firmware automatically.

stock firmware

Where to go next

This quickstart is intentionally bare-bones. The production firmware for this board adds per-pad configuration (edited via a USB-drive config mode), a physical mode jumper with boot-hold special modes, and full 12-pad polyphonic touch handling // that firmware isn't public yet. Start from these two example files and build up from here.

For the full pad reference, firmware download, and live MIDI/HID testers, see the dpx_biz onesheet.