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Valve v1 lighthouses include a power management feature implemented over the Bluetooth LE protocol. The protocol and the message format used by this feature are briefly described (among others) herehttps://github.com/nairol/LighthouseRedox. How this feature works will follow.

NOTE: There is a similar Python script to control Valve v2 lighthouseshere.

In the most usual setup, the lighthouses are used in a pair, where one LH is switched into "B" mode (becomes the master) and the other one into "C" mode (becomes the slave). In this configuration, "C" can only run when also "B" is running. The consequence is that powering off "B" will put "C" into stand-by, i.e. to turn off both LHs it only needs that "B" is turned off. Conversely, if "C" is in stand-by, turning "B" on will also wake up "C".

"B" can be turned off either by simply cutting the power (disconnecting from the power outlet). "B" cannot be directly turned off by a BT LE command, because the BT LE power management of the lighthouses is based on the notion ofkeeping the lighthouses on rather than onturning them on and off.

To keep "B" running, one needs toping "B" regularly over BT LE. If those pings stop then "B" will turn off after the specified timeout has been reached. This setup ensures that "B" will turn off even if the controller (e.g. SteamVR running on the user's PC) crashes. This also explains why there is no command for turning the lighthouse off - it will not be reliable.

Theping itself, apart from keeping the lighthouse on,can also turn it on (from stand-by). So the only solution to turn the already running lighthouse off is to instruct it with relatively short timeout, and then let the timeout expire.

Theping uses the command describedhere. Following examples assume a linux machine withbluez package installed.hcitool,hciconfig,gatttool are parts of this package.

Offset | Type   | Name             | Description-------|--------|------------------|------------0x00   | uint8  | unknown          | 0x120x01   | uint8  | cc               | command: 0x00, 0x01, 0x020x02   | uint16 | tttt             | timeout in sec. (big-endian)0x04   | uint32 | YYXXVVUU         | lighthouse ID or 0xffffffff (little-endian)0x08   | uint8  |                  | 0x00...    | ...    |                  | ...0x13   | uint8  |                  | 0x00

Let's assume thataa:bb:cc:dd:ee:ff is "B" LH MAC address andUUVVXXYY is its binhex ID, which can be found either on the LH enclosure or read from OpenVR database, where the LH is identified asLHB-UUVVXXYY. Ping can be then executed as BT LE write command to the characteristic with the handle0x0035 this way:

gatttool --device=aa:bb:cc:dd:ee:ff -I[aa:bb:cc:dd:ee:ff][LE]> connect[aa:bb:cc:dd:ee:ff][LE]> char-write-req 0x0035 12ccttttYYXXVVUU000000000000000000000000

Note that timeouttttt is encoded in big-endian, while lighthouse ID uses little-endian. The timeout specifies the time in seconds in which the lighthouse will go into stand-by if it does not receive anotherping. For the detailed description of the communication protocol (commands) seePROTOCOL.md.

The implemented solutionlhctrl.py uses Pythonbluepy package to accessbluez BT LE API. The script runs theping command explained above in the loop. First it wakes the LH "B" up, with the specified timeout, and then keeps pinging it, until it is either killed, or the global timeout expires.

usage: lhctrl.py [-h] -b LH_B_ID [-c LH_C_ID] [--lh_b_mac LH_B_MAC]                 [--lh_c_mac LH_C_MAC] [--lh_timeout LH_TIMEOUT] [--hndl HNDL]                 [-g GLOBAL_TIMEOUT] [-i INTERFACE] [-p PING_SLEEP]                 [--try_count TRY_COUNT] [--try_pause TRY_PAUSE] [--cmd2 CMD2]                 [-v]Wakes up and runs Vive lighthouse(s) using BT LE power managementoptional arguments:  -h, --help            show this help message and exit  -b LH_B_ID, --lh_b_id LH_B_ID                        BinHex ID of the "B" lighthouse (as in                        LHB-<8_char_id>)  -c LH_C_ID, --lh_c_id LH_C_ID                        Hex ID of the "C" lighthouse (as in LHB-<8char_id>)  --lh_b_mac LH_B_MAC   BT MAC of the "B" lighthouse (in format                        aa:bb:cc:dd:ee:ff)  --lh_c_mac LH_C_MAC   BT MAC of the "C" lighthouse (in format                        aa:bb:cc:dd:ee:ff)  --lh_timeout LH_TIMEOUT                        time (sec) in which LH powers off if not pinged [60]  --hndl HNDL           characteristic handle [53]  -g GLOBAL_TIMEOUT, --global_timeout GLOBAL_TIMEOUT                        time (sec) how long to keep the lighthouse(s) alive                        (0=forever) [0]  -i INTERFACE, --interface INTERFACE                        The Bluetooth interface on which to make the                        connection to be set. On Linux, 0 means /dev/hci0, 1                        means /dev/hci1 and so on.  -p PING_SLEEP, --ping_sleep PING_SLEEP                        time (sec) between two consecutive pings [20.0]  --try_count TRY_COUNT                        number of tries to set up a connection [5]  --try_pause TRY_PAUSE                        sleep time when reconnecting [2]  --cmd2 CMD2           second byte in the data written to the LH [2]  -v, --verbose         increase verbosity of the log to stdout