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.

PICO SDK Install

Run the pico_setup.sh cloning from https://github.com/raspberrypi/pico-setup.git.

git clone https://github.com/raspberrypi/pico-setup.git
cd pico-setup
export SKIP_VSCODE=1 && bash pico_setup.sh

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 .. # you might use `-DPICO_BOARD=pico_w -DPICO_SDK_PATH=/your/path/to/pico-sdk` if environment is not set
make -j <no. of parallel threads>

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

Upload and Play

Hold the boot button and connect the Pico W to PC using USB. Drag and drop the picow_ds4.uf2 file from build/src to Pico W Mass Storage. You also can use similar command.

cp src/picow_ds4.uf2 /media/pi/PICOW # Just hit `tab` `tab` after `/media`.

Long press share and PS4 button simultaneous untill fast blink of PS4 LED. It will connect to Pico W. Pico W blinks its green LED if no controller is connected and solid green if it detects and connects to a controller.

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.