>In addition, Bluetooth offers higher bandwidth (up > to 723 Kbps) than RS-232. Only if you are communicating between two pure Bluetooth devices. Using a RS232 to Bluetooth module to transmit is still limited to RS232 speeds since the source of the data is still RS232.
----- Original Message ----- From: "Peter Easton" <[EMAIL PROTECTED]> Newsgroups: palm-dev-forum To: "Palm Developer Forum" <[EMAIL PROTECTED]> Sent: Saturday, November 01, 2003 6:29 PM Subject: Re: SrmReceiveCheck Workaround > Hi Mike, > > >>Does BT on the Palm not have the buffer delay bug? > No, the BT radio forwards packets to the Palm BT stack as soon as it receives > them. The Palm can ACK packets in less than 1 ms, and respond to inbound > packets in less than 2ms. In addition, Bluetooth offers higher bandwidth (up > to 723 Kbps) than RS-232. > > As a "cheap" experiment, it might be worth getting a RS-232 <--> Bluetooth > adapter and connecting it to your hardware, then make a small change in your > app to use the Bluetooth RFCOMM virtual serial driver. You use the driver like > any other serial port; use the SrmOpen or SrmExtOpen calls to open it and the > SrmXXXX calls to send/receive data and close the port. > > Unfortunately, you need to poll the BT serial driver for inbound data > (SrmReceiveCheck). If you call the BT library directly you receive a > notification of inbound data so you don't need to poll and you get your data > immediately. Of course, this is a lot more work, but you have some sample code > like BtLibTest and BtPiconet which don't do exactly what you want but provide a > good starting point. For the RFCOMM virtual driver, take a look at the > BtCommVdrvr.h file in the OS 5 R3 SDK. > > I have two freeware apps: BtSerial which uses the Srm calls and polls for data > and BtSerial Pro which uses the Bluetooth library directly and receives data > the instant it is available. > > I haven't done any work to verify the latency over Bluetooth. I'd be > interested in knowing if it meets the theoretical figures mentioned above. > With a bit of work I could run some Palm-to-Palm tests. Unfortunately I can't > use my BtServer app since it polls for inbound data; I'd have to create > "BtServer Pro" which will use the BT lib directly. > > Regards, > > Peter > > http://www.whizoo.com > Contractor for hire (PalmSource Certified Developer) > Source code available for all apps!! > BtSerial Pro - Serial Port Client for the Palm OS > BtSerial - Bluetooth Serial Port Client for the Palm OS > BtServer - Bluetooth Serial Port Server for the Palm OS > Net Sync - Programmatically manipulate network settings > RegCode - Add registration code support to your app > > > > -- > For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/ > -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
