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Topic: how fast is a bluetooth keyboard?? (Read 1 time) previous topic - next topic

jon

so, i figured a few people here may have experience using wireless bluetooth keyboards, and was wondering if anyone knows what a typical response time would be for keystroke data to be received by the OS.

why do i ask?  i'm working on a musical instrument design that involves a wireless pedal/button interface.  i need a solution that is very cheap and suitable for use in a stage environment at a distance of about 5-7 meters.  i also need one that has a fast response time to minimise "latency".  ideally i would like keystroke data to have a maximum 1ms transmission time.

is this possible with a bluetooth interface?  i seems quite easy to find relatively cheap wireless BT keyboards these days, so i thought i'd give it a go.

cheers,

jon.

PaulS

Typically, bluetooth operates at 115200 baud. That allows you to transmit 11,500 characters per second. I think your requirement is covered.

MarkT

Also for a musician to use the repeatability of latency is probably more important that actual latency - for instance the latency of a piano keyboard is probably a lot more than 1ms...
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James C4S

Quote
i need a solution that is very cheap and suitable for use in a stage environment at a distance of about 5-7 meters


Is there a clear line of sight?  Even though BT is RF, anything between the devices will significantly reduce the range.  Also, 5-7 meters feels like a long range for a keyboard, a device typically less than 1 meter away from the host.
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thebigphish

now this is a bit old, but how about slapping an external antenna on the bluetooth module?
yes, have some.

jon

great... thanks for the ideas guys.

the link for the BT dongle external antenna (thanks bigphish) is slightly corrupt - correct address is:
http://www.pentest.co.uk/documents/bt_dongle_mod/bt_dongle_mod.html
i'm using my laptop's internal BT receiver so not sure i can do that - but actually i think 5-7 meters is an absolute maximum distance for me - normally it should be round 1-2meters...

think i'll have a go hacking a BT keyboard and hopefully post findings here...

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