Missing output reports

[didix16]

Hello there, I'm trying to do an experiment with PS4 Dualshock controller and I'm trying to connect and send back data through Bluetooth. However, when I want to send data back (OUTPUT) it fails because I need to send to report 0xA2 and there is no such report listed by HIDDevice. These are are only reports that are listed:

If I try to send data to an other report other thant these I get the following message: Uncaught (in promise) NotAllowedError: Failed to write the report..

So is there a kind of bug or limitiation on browser? Because on Node.Js works perfectly.

Thanks in advance

[nondebug]

DualShock4's 0xA2 is a feature report, it should be in featureReports (the screenshot shows outputReports) and you should use sendFeatureReport instead of sendReport.

https://wicg.github.io/webhid/#sendfeaturereport-method

It's interesting that it works in node-hid, are you using write or sendFeatureReport? Can you share the relevant code?

https://github.com/node-hid/node-hid?tab=readme-ov-file#writing-to-a-device-1

It looks like 0xA2 is "enable DFU mode".

https://blog.the.al/2023/01/03/ds4-reverse-engineering-part-3.html

[didix16]

Hi @nondebug thanks for you answer! I readed here https://www.psdevwiki.com/ps4/DS4-BT#HID_OUTPUT_reports that 0xA2 it must be send as an output report with payload like LED color, sound, rumble, etc. However I didn't see either the 0xA2 featureReport anounce it.

It's interesting that it works in node-hid, are you using write or sendFeatureReport? Can you share the relevant code?
I'm using write to send though node-hid as output and it works perfectly. I didn't test it with send report.

Well the code I'm using I picked up from this repo: https://github.com/Pecacheu/dualshock. I'm just trying to fix the part where you can send audio to the controller by sending sbc data

[nondebug]

On that page the 0xA2 is HIDP-Hdr from the Bluetooth HID profile and not the report ID. You don't have to worry about including this byte, the operating system takes care of it. However, for DS4's output report 0x11 it needs to be included when computing the CRC32 checksum.

[didix16]

So are you saying that I must start the payload with 0x11, do de CRC checksum with that byte as first byte and send to the output report 17 (0x11)?

Because in node-hid i had to add the 0xA2 byte to payload to the the checksoum and then I had to remove it from the begining. This is from Pecacheu repository:

I'm gonna try the output 0x11 and see what can I get, thanks!

[didix16]

Finally I made it work!! I made some tests but at the begining nothing happens. It turns that I was sending also the report ID on the payload. Also I've changed the CRC library. Seems that the initial one was not working well.

Thanks for your help @nondebug