[HOGP] Android auto-plays music when hogp devices disconnect

[knight]

Hi all, I can control volume up/down, music play/pause with the ble_hids module.

static uint8_t report_map_data[] = { 0x05, 0x0c, // Usage Page (consumer device) 0x09, 0x01, // Usage (consumer control) 0xA1, 0x01, // Collection (application)

0x09, 0xB0,                 //     Usage (play)
0x09, 0xB1,                 //     Usage (pause)
0x09, 0xB7,                 //     Usage (stop)
0x09, 0xB5,                 //     Usage (next)
0x09, 0xB6,                 //     Usage (previous)
0x09, 0xCF,                 //     Usage (voice command)
0x15, 0x01,                 //     Logical Minimum (1)
0x25, 0x06,                 //     Logical Maximum (6)
0x75, 0x04,                 //     Report Size (4 bit)
0x95, 0x01,                 //     Report Count (1)
0x81, 0x00,                 //     INPUT (Data, Array, Absolute)

0x09, 0xE9,                 //     Usage (Volume Up)
0x09, 0xEA,                 //     Usage (Volume Down)
0x15, 0x01,                 //     Logical Minimum (1)
0x25, 0x02,                 //     Logical Maximum (2)
0x75, 0x02,                 //     Report Size (2 bit)
0x95, 0x01,                 //     Report Count (1)
0x81, 0x00,                 //     INPUT (Data, Array, Absolute)

0x05, 0x07,                 //     Usage Page (keyboard)
0x09, 0x58,                 //     Usage(return)
0x09, 0x28,                 //     Usage(enter)
0x15, 0x01,                 //     Logical Minimum (1)
0x25, 0x02,                 //     Logical Maximum (2)
0x75, 0x02,                 //     Report Size (2 bit)
0x95, 0x01,                 //     Report Count (1)
0x81, 0x00,                 //     INPUT (Data, Array, Absolute)

0xC0                        // End Collection (Application)

};

But whenever bluetooth device on Android is closed or ble connection drops, the music player auto start playing music.

[Håkon Alseth]

When providing the descriptor with the "INPUT" bits that you have set (DATA, ARRAY, ABSOLUTE), are you also clearing the signal after sending a command?

Let's say that you send "PLAY", which boils down to 0x01 in this case, you will also have to send a release-key (0x00) afterwards.

By default on Android, command "PLAY" will start the music player.

Q1: Could you provide a sniffer trace showing the issue? You can capture this using our ble-sniffer

Q2: Do you see the same issue if you try disconnecting using this example? github.com/.../nrf51_ble_app_hids_kbd_consumercontrol

Cheers, Håkon

[knight]

Hi Håkon, We must send 0x00 after every key event immediately, otherwise the android or IOS side would act abnormal behavior. For instance, the phone would be in the state of increasing volume infinitely after we send a volume key. IOS behaves normally in our case, only android goes wrong.