Pairing is done only once. Next time when the adapter is turned on, it will connect to the paired host if it is available.
If you like to to pair the adapter with a different host, you must unpair it from the current host first before pairing the new
one. Erasing all paired devices in the adapter itself (the device clear command) will not erase the bonding. If you pair
a new host without unpair the old one first, and if both hosts are turned on at the same time, unexpected behavior may
happen.
Command mode: command mode is used to configure adapter features. To enter command mode, pair the adapter with a host. Open
a text app (i.e., Notes, Notepad). Make sure when you type on the keyboard, the text enters into the App. Press and hold the power
button for about 2 seconds. The following text will be emitted:
BT KB Adapter Firmware v4.0
2017 Handheld Scientific, Inc.
Type help or ?
>
Now the adapter is in command mode. Press the power switch again to exit. In command mode, key strokes are interpreted by the
adapter as commands. Output is directed to the host. Commands are all lower cases and terminated by Return or Enter. They need to
be typed in exactly as shown below. Due to resource constraint, the parser may not give detailed error if it does not under a command.
Enter “help” or “?” for a list of commands which may change from one firmware version to another. The following is all available
commands in firmware version 2.0.
show -- Display useful adapter information such as battery voltage, USB output voltage and settings.
save -- Save changes so they will persist across power cycles.
exit –Exit command mode. Same as pressing the power button.
device clear –clear paired devices in the adapter. This will speed up startup re-connection.
reboot –Restart adapter. Same as power cycle.
set bt name [name]
Set the device name to name.
set keycode [on|off]
Display USB key events. For information or debugging purpose. Each key press generates two events: key down and up. Each
event is represent by 8-bytes. Press power button to exit key code display and back to command mode.
set time idle_shutdown [time]
Set idle (inactivity) shutdown time. Value 0 disables this feature. Example: set time idle_shutdown 900 (set idle
shutdown time to 900 seconds or 15 minutes)
set voltage low_bat_shutdown [voltage]
Set low battery shutdown voltage. Value 0 disables this feature. Example: set voltage low_bat_shutdown 3.4 (set
voltage to 3.4)
set map keypad_enter [on|off]
Turn on/off mapping of keypad Enter key to normal Enter key. The Enter key in the numeric keypad generates a different key
code than the normal Enter key. iOS devices do not interrupt this key code correctly. This configuration fixes the issue.
keepalive
Display keep-alive settings. If keep-alive is enabled (period is non-zero), the adapter will send out key strokes periodically. This is
useful in preventing the host from falling into sleep or network from timing out due to inactivity. There are 3 settings related to keep-
alive: period and key.
keepalive period [time]
How often keys are sent (in second). Value 0 disables the feature. Example: keepalive period 60 (set period to 60
seconds)
keepalive key
Set the keys to be sent. After issuing this command, press the key(s) to be sent. Usually one key is enough but you can use up to 4
keys. Each key press will generate two events: key down and key up. Press the power button to end input.
