DualShock 4 on Pico-W

This is a pretty crude project which brings up a Sony DualShock 4 (PS4) controller on Pico-W.

It uses a hard-coded controller MAC address (see src/bt_hid.c), that needs to match your controller.

On first boot, make sure the controller is in "pairing" mode (hold "Share" and the PS button, so the light is doing quick double-flashes).

Once paired, it's enough to just press the PS/Home button to reconnect.

Building

The DS4 has a large HID descriptor, which doesn't fit in upstream BTStack's SDP buffer, so this project submodules a fork of BTStack wich just makes that larger.

So, clone this repository, then:

cd picow_ds4
git submodule update --init --recursive
mkdir build
cd build
cmake -DPICO_BOARD=pico_w -DPICO_SDK_PATH=/your/path/to/pico-sdk ../
make

The .uf2 file will be build/src/picow_ds4.uf2

Known Issues

pico-sdk implements its own btstack makefile (see $PICO_SDK_PATH/src/rp2_common/pico_btstack/CMakeLists.txt), which means a particular pico-sdk version is only technically compatible with a single btstack version. See raspberrypi/pico-sdk#1553 and #1.

If you run in to build issues which look related to btstack, it could be because the version this project depends on has diverged from your version of pico-sdk again.

This repo is known to build OK against pico-sdk version 6a7db34ff63345a7badec79ebea3aaef1712f374 (tag: 1.5.1).

There's two good ways to fix this, which maybe I'll do one day:

1. Upstream a configurable MAX_ATTRIBUTE_VALUE_SIZE to btstack, so that the btstack submodule could be removed here.
2. Change btstack+pico-sdk to put the make rules inside btstack instead, so that there's no implicit dependency between the two.