Bluetooth Adapter for Keyboard/Mouse FAQ

1. What USB devices does the Adapter work with?

The adapter works with only USB keyboards and mice, as well as keyboard-emulating devices like bar code scanners, magnetic strip readers (credit card readers) and RFID readers. It does not work with any other types of USB devices such as game controllers, video capturing boards, audio devices or serial port adapters. The adapter relies on standard HID support built-in to common OS’s. Any custom driver/software from the keyboard vendor will NOT work with the adapter.

2. Does the adapter have latency (lag)?

For USB to USB bridging, there is no noticeable lag.

For Bluetooth connection, as a wireless device using shared transmission channels, it is not as quick as wired connection but it is acceptable for normal typing use. Your mileage may vary for gaming applications though. There is no difference between a keyboard connected to the Adapter and any wireless keyboard with regarding to latency.

3. May I use the Adapter with a USB hub?

The Adapter firmware has the capability to work with a USB hub with up to two mice/keyboards connected. So a keyboard with a built-in hub, without any device plugged in the hub, is officially supported. However, an external hub, or a keyboard with a built-in hub where there is another device plugged in the hub, is not officially supported.

Since firmware 6.0.0, hub support has been greatly improved. They will most likely work if you stick to the following: (1) USB 2.0/1.1 hubs only. 3.x hubs will not work (nor is it worth the money using with kb/mouse). (2) Use a 4-port (or less) hub. If you have a hub with more than 4 ports, chances are that inside it has 2 hub chips in cascade, so only the ports connected to the first chip will work, others don’t. So test all ports. (3) The simpler the hub is, the more likely it will work.

4. Do you have plan to add another USB connector so we can use a keyboard and a mouse at the same time (without using a hub)?

Currently there is no plan to add another connector, based on the following considerations:

  1. The main market of this product is with tablets and smartphones where no USB port is available. Those use touch screens not mice. So an additional port for a mouse would not be necessary.
  2. We are satisfied with the size (especially the height) of the adapter. Adding another port would increase the size significantly.
  3. USB is a complex technology. Adding another port would add non-trivial amount of cost.

We always monitor technology progress and listen to customer feedback. We evaluate our decisions from time to time, so this may change in the future.

5. Do you have plan to “upgrade” the adapter to use USB-C?

Currently there is no plan to change the connectors to USB-C, based on the following considerations:

  1. USB-C connectors are small and fragile.
  2. All keyboards with USB-C come with a C to A cable so there is no problem using them with our Adapter.

We always monitor technology progress and listen to customer feedback. We evaluate our decisions from time to time so this may change in the future.

6. Can I use a battery power bank to power the adapter?

Absolutely. Virtually any battery power bank will do. So you can have some mobility. It is worth noting that some power banks have auto shut-off feature. If the current consumption of the adapter+keyboard is less than the power bank’s detection threshold, it will think there is nothing connected, and shut itself off after a certain amount of time. So you may want to select a power bank without auto-shutoff, or see question #8 below.

7. How much current can the adapter supply to the connected keyboard?

The adapter simply passes the power from the male connector to the female connector so the limit is up to the power source.

8. How do I keep the power bank from shutting off?

Many battery power banks have the auto shutoff feature where a power bank shuts itself off after some period of time if it detects no device connected to its output. In some cases the power consumption of the adapter+keyboard is below its detection threshold. As such the power bank still shuts itself off even when the adapter+keyboard is connected. To solve this issue, in firmware 5.4.0 and up, we implemented a feature to periodically discharge larger amount of current (about 130 mA) to keep the power bank alive. Use the following commands to set it up:

> set discharge duration 2
> set discharge interval 50
> save
> reboot

This instructs the adapter to discharge larger current every 50 seconds for 2 seconds to keep the battery alive. The discharge interval should be set to slightly shorter than the battery’s timeout length. For example, if the battery shuts itself off in 60 seconds, set the interval to 50. If the battery shuts itself off in 30 seconds, set the interval to 25.

9. What is the battery capacity that I need, or how long will my battery last?

The battery supplies power to both the adapter and the connected device (keyboard or mouse). The adapter itself consumes about 40mA of current. The power consumption of the connected device varies greatly, from 20mA to a few hundred mA with back-light on. As an example, assuming the keyboard consumes 50mA. If the capacity of the battery is 4000mAH, then the time of continuous use for a fully charged battery to last is:

4000/(40+50)= 44.4 hours

You can calculate the lasting time of your battery based on the above example.

10. When I connect a USB RFID reader, magnetic strip reader or some other keyboard-emulating devices to the adapter, the output is losing characters. What can I do?

This is because those USB devices output data at high rate. It is ok with wire USB connection but Bluetooth wireless may not be able to handle that rate. We anticipate this situation and have a throttle feature in the adapter to slow down the data. To enable this feature, enter command mode and type in the following:

> set time throttle 10
> save
> reboot

This will add 10ms delay between each character. You should see the output slowing down. If that is not enough (still missing characters), increase the delay to 20, 30, …, until all characters are output reliably. Setting delay to zero instructs the adapter to send out characters as soon as it receives them, effectively disables the feature.

11. How do I set up the adapter as a mouse jiggler?

Operating systems have a feature called idle lock screen: when there is no input activity (keyboard or mouse) for a certain amount of time, the screen will be locked and require typing in the password to unlock. For corporation laptops, often this feature cannot be disabled due to security concern. It is sometimes annoying if you work in a known secure environment such as at home. There are products called mouse jigglers which generate a mouse movement periodically to prevent screen locking. Using a small mouse movement is better than keyboard input since it has little effect on the user’s activity (such as typing). Our Bluetooth adapter can be setup for this purpose using a timer. Enter command line and enter the following:

> timer 1 period 60
> timer 1 key mouse:0:1:0
> save

This will set up the adapter to send out a mouse movement of 1 pixel every 60 seconds, enough to keep the screen from being locked but won’t disrupt normal activity. The same setup can be used to through Bluetooth to prevent the connection from timing out due to inactivity on the host side.

12. How do I enable the media keys in some Apple keyboards?

Some Apple keyboards (e.g., the A1243) have the top row function keys as media keys. For example, F7 is Previous Track, F8 Play, F9 Next Track. When such a keyboard is used with MacOS, those keys are defaulted to media control. The FN key switches them to function keys. However, when the keyboard is used with Non MacOS (e.g., Windows), those keys are defaulted to function keys. One has to install extra software or driver so as to enable those for media control (search “apple keyboard media keys for windows”). With the BT-500 adapter, you can setup key mappings to enable the media key functions. If you don’t use the F7-F11 functions, enter command mode and type the following:

> map add f7 prev
> map add f8 play
> map add f9 next
> map add f10 mute
> map add f11 vol_dec
> map add f12 vol_inc
> save

The Eject (F12) control is seldom used nowadays so it is not mapped. If you do need to use the F7-F11 functions, you can  add the following key mappings instead of the above ones:

> map add ctrl+f7 prev
> map add ctrl+f8 play
> map add ctrl+f9 next
> map add ctrl+f10 mute
> map add ctrl+f11 vol_dec
> map add ctrl+f12 vol_inc
> save

Media control is achieved by pressing the corresponding function key while holding the Ctrl key. You can set up to use a different modifier key (e.g., Shift, Alt or COM) or two modifier keys. Also the mappings are saved in the Adapter itself so they are available with using any host.

13. Do those programmable keys seen in some keyboards work?

Some keyboards have those programmable keys. For example, all keys on Logitech G13 are programmable. Users need custom software or device driver from the keyboard manufacturers to program the keys, and in the majority cases to use those keys. Whether the keys would work with the Adapter depends on where the key information is stored: in the software/driver or in the keyboard itself. The best way to test is to use the keyboard on a machine that does not have the custom software/driver installed. If the keys work there then the information is stored in the keyboard itself, and they most likely will also work with the Adapter. However, if the keys no longer work with the PC without the software/driver installed then they most likely won’t work with the Adapter.

14. Do you ship to my country?

Yes we ship worldwide for a flat fee (i.e., same fee no matter how many items you purchase).

15. Do you accept this payment method (TT, wire transfer, etc.)?

For small quantity PayPal is the only payment we accept. PayPal takes many forms for payment such as credit cards, e-check, etc. For larger quantity, please contact us (support at

Send you questions to support at Or use our web form. We appreciate your feedback.