Bounty - Bluetooth support using the Pico W

[Fortinbra]

We would like to have support for Bluetooth and the Pico W board.

Requirements

• MUST maintain USB compatibility

• MUST support at least X-Input modes via Bluetooth.

We need to still be able to use the controller as a USB controller when plugged in, or a Bluetooth controller when not.

This is purely from the firmware perspective. Hardware for battery management and charging will be a separate effort.

Addition Considerations

Would be nice to have.

• Pimoroni Lipo Amigo Pro battery management.
  https://shop.pimoroni.com/products/lipo-amigo?variant=39779302539347
• Web Config over Bluetooth.
• All existing USB modes over Bluetooth.

[TheTrainGoes]

We chatted about this and are going to break it down into two separate bounties.

Part 1 will be a proof of concept. This proof of concept is an MVP to see if it is even viable as a controller and has reasonable lag / performance / etc.

This part can be quick and easy.

Part 2 will be the full incorporation into GP2040-CE.

[LeeNX]

Part 1 should be covered by PR bluekitchen/btstack#209.

Extending the HID for more buttons,axis and modes could be seen in https://github.com/lemmingDev/ESP32-BLE-Gamepad

and possibly ForceFeedback with https://github.com/YukMingLaw/ArduinoJoystickWithFFBLibrary

[Fortinbra]

Part 1 should be covered by PR bluekitchen/btstack#209.

Extending the HID for more buttons,axis and modes could be seen in https://github.com/lemmingDev/ESP32-BLE-Gamepad

and possibly ForceFeedback with https://github.com/YukMingLaw/ArduinoJoystickWithFFBLibrary

While this is great information to have. What I'm looking for, for the bounty, is someone to actually make a demonstration using our codebase as the example.

[dogtopus]

I didn't know Pico W also supports Bluetooth Classic (a crucial thing to have for emulating most console Bluetooth controllers) until now.

We might actually get somewhere pretty far with this bounty. GP2040 DIY handheld controller anyone?

[TheTrainGoes]

@dogtopus yes please!

My dreams of a cord free Switch arcade stick are still within reach :)

[HoboDev]

Since the chip is connected via SPI... could this eventually be ported over to use ESP?

[dogtopus]

Since the chip is connected via SPI... could this eventually be ported over to use ESP?

In theory yes but we will eventually run into the issues with Bluekitchen's license agreement since it's not technically free software and from what I heard from them years ago, requires commercial licenses even if the firmware is open source but loaded officially to a board (open source or not) for sale.

RPi foundation licensed from them so the Bluekitchen stack can be used on Pico W free of charge but that only limits to Pico W.

(Also take this with a grain of salt since looks like their intention was to make it available for use with RP2040 and not just Pico W. It's better to formally ask them once we actually need to use the stack on non-Pico W boards.)

[hizzlekizzle]

Bluetooth support would also open the door for DIY receivers to connect bluetooth gamepads to S/NES or Wii extensions, right? That is, using the board as a receiver rather than a transmitter; similar to the SNES 'retro receiver' from 8bitdo?

[Fortinbra]

Since the chip is connected via SPI... could this eventually be ported over to use ESP?

For GP2040-CE, we don't have any plans to support any platforms other than the RP2040. You're always welcome to fork, and do your own thing.

[Fortinbra]

Bluetooth support would also open the door for DIY receivers to connect bluetooth gamepads to S/NES or Wii extensions, right? That is, using the board as a receiver rather than a transmitter; similar to the SNES 'retro receiver' from 8bitdo?

We need to get transmission working first.

[dogtopus]

Since the chip is connected via SPI... could this eventually be ported over to use ESP?

For GP2040-CE, we don't have any plans to support any platforms other than the RP2040. You're always welcome to fork, and do your own thing.

I think they meant using ESP as an HCI, which I'm not sure if the license for the Bluekitchen stack in pico-sdk permits such use case.

[Fortinbra]

Since the chip is connected via SPI... could this eventually be ported over to use ESP?

For GP2040-CE, we don't have any plans to support any platforms other than the RP2040. You're always welcome to fork, and do your own thing.

I think they meant using ESP as an HCI, which I'm not sure if the license for the Bluekitchen stack in pico-sdk permits such use case.

Oh, in that case, we're only utilizing what is available from the SDK, and we'll deviate after we have something working, if we have reason to.

[futaris]

I know I said I'd have this working last month. I ended up ordering a couple more Pico Ws so I can implement this.

[sanjay900]

Bluetooth support would also open the door for DIY receivers to connect bluetooth gamepads to S/NES or Wii extensions, right? That is, using the board as a receiver rather than a transmitter; similar to the SNES 'retro receiver' from 8bitdo?

Just as a sidenote, having done this for a project of my own, there is a bug with the current Bluetooth driver that limits pico hid host polling pretty badly, raspberrypi/pico-sdk#1342

I was mostly focused on making pairs of transmitters and receivers as I was building wireless controllers with console support, but from what I understand that bug should affect receiving from hid in general

Mind you, I guess that's only a problem for non classic, and I suspect everything you'd be doing here would be bt classic anyways