DivaCon2040

DivaCon2040 - Firmware for RP2040/RP2350 based Project Diva controllers

DivaCon2040 is a firmware for DIY Project Diva Arcade controllers based on the RP2040/RP2350 microcontroller as found on the Raspberry Pi Pico.

It is pretty much tailored to this specific use case, if you are looking for something universal, ready-to-flash and on-the-fly configurable I’d recommend to have a look at more generic approaches like GP2040-CE. If you however want build something more specialized or custom, feel free to use this project as a base, it is designed to be somewhat modular and should be easy remodel. See DonCon2040 for an example on how this could look like.

If you have any questions about the project in general or need hints how to build this thing, feel free to open a discussion anytime!

Features

• Various controller emulation modes
  • HORI PS4-161 Project Diva Arcade Controller
  • HORI NSW-230 Project Diva Arcade Controller
  • PD-Loader Arcade Controller (Compatible with PD-Loader’s Divaller driver)
  • PS4 Compatibility (will work on PS4, see PS4 Authentication for details)
  • Dualshock 4 (Will be recognised as DS4 on PC/Steam, but does not work on an actual PS4!)
  • Dualshock 3
  • Switch Pro Controller
  • XInput
  • Keyboard
  • MIDI
  • Debug mode (will output current state via USB serial and allow direct flashing)
• Arcade Style Touch Slider for arcade controller emulation modes (In Project Diva Games with arcade controller support: Enter the ‘Customize’ menu from song selection and enable arcade controller support under ‘Game/Control Config’ -> ‘Arcade Controller Settings’ for the slider to work properly.)
• Slider to analog stick mapping for standard controller modes
• Option to mirror face buttons to directional pad for games with ‘W’-arrows
• 1000Hz Polling Rate, ~2.4ms average latency, <0.7ms Jitter (Tested with Gamepadla/GPDL)
• Slider illumination using WS2812 LED strip (can be controlled by PD-Loader)
• Button illumination (can be controlled by PD-Loader)
• Basic configuration via on-screen menu on attached OLED screen
• BPM counter

Game Compatibility

Title	Platform	Official Arcade Slider Support	Recommended Mode	Notes
Hatsune Miku -Project DIVA- Dreamy Theater	PS3	No	Dualshock 3 + ‘Double Btn’	- Untested but will likely work. - Slider can be used for Star notes. - Enable ‘Double Btn’ to make hitting ‘W’-arrows easier.
Hatsune Miku -Project DIVA- Dreamy Theater 2nd	PS3	No	Dualshock 3 + ‘Double Btn’	- Slider can be used for Star notes. - Enable ‘Double Btn’ to make hitting ‘W’-arrows easier.
Hatsune Miku -Project DIVA- Dreamy Theater extend	PS3	No	Dualshock 3 + ‘Double Btn’	- Untested but will likely work. - Slider can be used for Star notes. - Enable ‘Double Btn’ to make hitting ‘W’-arrows easier.
Hatsune Miku -Project DIVA- F	PS3	No	Dualshock 3 + ‘Double Btn’	- Slider can be used for Star notes. - Enable ‘Double Btn’ to make hitting ‘W’-arrows easier.
Hatsune Miku -Project DIVA- F2nd	PS3	No	Dualshock 3 + ‘Double Btn’	- Slider can be used for Star notes. - Enable ‘Double Btn’ to make hitting ‘W’-arrows easier.
Hatsune Miku -Project DIVA- Future Tone	PS4	No	PS4 Compat	- See PS4 Authentication - Game does not support arcade style slider, stick emulation will be used.
Hatsune Miku -Project DIVA- Future Tone DX	PS4	Yes	PS4 Diva	- See PS4 Authentication - From song selection enter the ‘Customize’ menu and enable arcade controller support under ‘Game/Control Config’ -> ‘Arcade Controller Settings’.
Hatsune Miku -Project DIVA- X	PS4	No	PS4 Compat + ‘Double Btn’	- See PS4 Authentication - Slider can be used for Star notes. - Enable ‘Double Btn’ to make hitting ‘W’-arrows easier.
Hatsune Miku: Project DIVA Mega Mix / Hatsune Miku -Project DIVA- MEGA39’s	Switch	Yes	Switch Diva	- When starting the game, choose ‘Arcade Mode’. - From song selection enter the ‘Customize’ menu and enable arcade controller support under ‘Game/Control Config’ -> ‘Arcade Controller Settings’.
Hatsune Miku -Project DIVA- Arcade Future Tone (PDLoader)	PC	Yes	PDL Arcade	- Should work out-of-the-box. (You might need to enable slider_in_menus in keyconfig.ini and Hardware_Slider in config.ini). - ‘PS4 Diva’ also works, see here for configuration.
Hatsune Miku: Project DIVA Mega 39s+ / Hatsune Miku: Project DIVA Mega Mix+	PC	Yes	PS4 Diva or Switch Diva	- From song selection enter the ‘Customize’ menu and enable arcade controller support under ‘Game/Control Config’ -> ‘Arcade Controller Settings’.

Building

I highly recommend to build the firmware yourself so you can make adjustments in include/GlobalConfiguration.h to match your specific controller build. If you still want to use a binary release, you need to connect everything according the default configuration as described here.

VSCode (Windows, Linux, MacOS)

Install VSCode and get the Raspberry Pi Pico extension. From the extension choose ‘Import Project’ and select the folder where you’ve checked out this repository, then use ‘Compile Project’.

CLI

See pico-sdk readme for a list of pre-requisites.

Use the environment variables PICO_SDK_PATH to use a local pico-sdk, and PICO_BOARD to select another target board. By default the pico-sdk will be fetched from Github and the target board will be “pico”.

For Rasberry Pi Pico:

cmake -B build -DPICO_BOARD="pico"
cmake --build build

For Rasberry Pi Pico 2:

cmake -B build -DPICO_BOARD="pico2"
cmake --build build

Configuration

Options which you probably want to change more regularly can be changed using the on-screen menu on the attached OLED display, hold both Start and Select for 2 seconds to enter it:

• Controller emulation mode
• Touch Slider LED mode, color and brightness
• Face button to directional pad mirroring
• Reset settings to defaults
• Enter BOOTSEL mode for firmware flashing

Those settings are persisted to flash memory if you choose ‘Save’ when exiting the Menu and will survive power cycles.

Everything else is compiled statically into the firmware. You can find defaults and hardware configuration in include/GlobalConfiguration.h. This covers default controller emulation mode, button pins, i2c pins, addresses and speed and slider type.

PS4 Authentication

The PS4 needs a controller to sign a cryptographic challenge every few seconds, otherwise it will stop working after around 8 minutes after plugging in. For the Project Diva games this is somewhat bearable, since you can re-plug the controller before starting each song to avoid running into the timeout during gameplay. Still, this is annoying.

DivaCon2040 can sign those challenges, but you will need to obtain some data from an original DS4 and compile it into the firmware. You will need a serial, signature and private key file. I can’t and won’t help you how to obtain those, you’ll need to figure this out yourself.

To build the firmware run scripts/generateAuthConfig.py in the folder where you placed the required files. Copy the resulting PS4AuthConfiguration.h to the include directory, replacing the existing header. Then build the firmware as described in Building.

Signing the challenge will block the second core of the RP2040 for 2-3 seconds, so LED animations and the display will appear stuck from time to time. Input handling is unaffected. On the RP2350 SHA256 is hardware accelerated, so signing time is reduced to about 1 second.

Hardware

Main IO Board

This project was designed and tested on the Raspberry Pi Pico. Other RP2040/RP2350 boards should also work if they expose enough GPIOs.

You can find the DivaConIO board in the pcb subfolder. This conveniently breaks out the GPIO pins into connectors and already comes with drivers for the button LEDs and level shifting for the slider LEDs.

It is however perfectly possible to build this on a piece of stripboard or the like. See this schematic here for details.

Touch Slider

The touch slider resembles the the slider of Project Diva Arcade Controllers and Cabinets, being a row of 32 individual touch sensors. For the two arcade controller emulation modes, the 32 sensors are mapped to the analog stick axes as described here and work just like the original controllers in-game. In Project Diva games which support arcade controllers (i.e. Mega Mix on PC/Switch), enter the ‘Customize’ menu from song selection and enable arcade controller support under ‘Game/Control Config’ -> ‘Arcade Controller Settings’ for the slider to work properly.

For other controller emulation modes, swipes on the left half of the slider will move the left stick left and right, while swipes on the right half will do the same on the right stick.

Electronics

The current Touch Slider is based on the MPR121 Capacitive Touch Sensor Controller. While the MPR121 seems to have a somewhat bad reputation to be hard to work with, I’ve had no issues with it so far and it works near flawlessly. That main downside is that is is out-of-production, there is however still sufficient supply on the usual marketplaces.

Current alternatives like the CAP1188 are almost universally to slow. During a quick slide, a finger spends roughly 10ms on a single touch pad while most controllers need scan cycles of at least 16-35ms. The MPR121 on the contrary can be configured down to around 1ms. The Lumissil IS31SE5117A looks promising, but I couldn’t get it to work yet. Other than that microcontrollers with integrated touch controllers are an option, but I don’t want to go down that route since there already is the LKP which does this. The LKP seems to have an i2c slave mode, so if you have access to one feel free to get in touch. I’d be happy to work on supporting the LKP but need someone to test.

All MPR121 controllers are attached to the same i2c bus, so make sure to have them use different i2c addresses accordingly. There is a slider variant with three and one with four controllers which can be configured in include/GlobalConfiguration.h (The four controller variant is the default). See below tables for the electrode mapping:

Three MPR121

	MPR 0	MPR 1	MPR 2
Pin	0…11	2…9	0…11
Electrode	31…20	19…12	11…0

Four MPR121

	MPR 0	MPR 1	MPR 2	MPR 3
Pin	4…11	4…11	4…11	4…11
Electrode	31…24	13…16	15…8	7…0

The MPR121s are setup for auto configuration with parameters taken from the Adafruit MPR121 Arduino Library. The ‘FDL falling’ value has been tweaked to allow slow slides. You might want to adjust the touch and release thresholds to your specific build.

Construction

There are two variants which both work equivalently well in my experience: You can use the DivaConSlider board from the pcb subfolder which hosts the MPR121s, electrodes and LEDs or you can build it by hand without a pcb.

For the latter I had success using 15mm wide copper tape strips with 2mm spacing in-between, aligning them properly using a 3D printed jig. Those are attached to off-the-shelf MPR121 breakout boards using the thinnest wire possible to reduce parasitic capacitance.

Both variants are covered by a sandwich made out of some thin 3M 468MP or 467MP adhesive, paper for the artwork, another layer of adhesive and 3mm of frosted acrylic. Is seems to be pretty essential to use the proper adhesive here to get an even bond and to avoid any air between the layers. The 3M tape mentioned above is recommended in the MPR121 application notes. I can be a bit hard to work with, but is manageable by spraying some soapy water on the surface beforehand to ease alignment.

For illumination of the non-pcb variant, I used Adafruit Side Light NeoPixel LED PCB Bars which have the perfect hight and spacing to light up each segment with two LEDs each, but other WS2812 compatible strips should work as well.

One word on the slider dimensions: Those are not arcade accurate but slightly larger. This stems from constraints of me building the non-pcb variant first (i.e. available copper tape and LED strip dimensions). See here for the actual dimensions or have a look at the LKP.

Buttons

Buttons are hooked up directly to the GPIO pins, pulling the pin to ground when pressed.

Supported are:

• Four face buttons, which are mapped according to the cardinal directions they appear on the respective controllers (North/East/South/West)
• DPad/Hat (Up/Down/Left/Right)
• Two shoulder buttons for each side (L1/L2/R1/R2)
• Two Stick buttons (L3/R3)
• Three vendor specific buttons (Options/TouchPad/PS on DS4, Start/Select/PS on DS3, +/-/Home on Switch, Start/Back/Guide on XInput)

For the four big buttons I used generic 100mm "Massive Arcade Button"s since those are much cheaper than the original Sanwa OBSA-100UMQ. They have same size an can be easily improved with the original OBSA-SP-200 200g springs and better switches, like the ridiculously expensive Sanwa OBSA-LHSXF or steelpuxnastik’s excellent DIY switches for a more authentic feel.

The other buttons are cheap generic 24mm arcade buttons.

Button LEDs

Illumination for the four face buttons can be controlled by GPIO pins. I recommend to not directly hook up the LEDs to the GPIO pins, but rather use a simple transistor based driving circuit since the power than can be delivered through the GPIOs is rather limited.

OLED Display

Just a standard SSD1306 OLED display with 128x64 resolution hooked up to the second i2c bus. Mind that the display is mandatory for changing any settings directly on the controller, if you want to omit it, change the defaults within the code accordingly (or navigate the menu blindly).

The ‘Box’

The enclosure is build with lasercut 5mm opaque black acrylic panels held together by aluminum profiles and some 3D printed spacers. Edges and the cradles the touch slider sits in are also 3D printed. The Artwork is sandwiched behind an additional layer of 4mm transparent acrylic.

Acknowledgements

• Adafruit for the figuring out some working MPR121 settings
• daschr for the SSD1306 OLED driver
• FeralAI for the inspiration and Dualshock3/XInput driver from the GP2040 Project
• dogtopus for his research on the arcade slider and various contributions to many controller related projects
• steelpuxnastik for the excellent SHINSANWASWITCH
• The linux kernel contributors for documenting the game controllers in their drivers