PicAxe + BlueSmirf Gold, Random Disconnects...???

Hi,

I have had quite a bit of experience with the BlueSmirf Gold and Picaxe for wireless PC communications, except there is one odd bug I can’t figure out - maybe someone out in the interwebs can help?

I’m using a picaxe 18m2, its hardware serial port is configured at 115k baud and so is the bluetooth module. If I continuously write to the serial port with the picaxe (no pause or wait between writes, picaxe at 32MHz), and monitor output in hyperterminal, output will scroll for a few seconds followed shortly by the bluetooth module disconnecting (status LED goes from green to red). The PC still thinks the comm port is open, bluetooth module seems to have decided to disconnect on its own for some reason, triggered by what???

If i add a lengthy pause between the serial out command inside the main loop on the uc the bluetooth disconnect is avoided. I can get the pause down to around 10ms before I start getting the disconnect problems intermittently.

Does anyone know why this is the case or what causes it?

And another thing, using win32 (c++) I can’t reliably determine the serial comms status due to this or find any specific errors or buffer overflows which may cause the PC to close the comm port (indeed comm port seems to remain open when this happens). A timeout reliably works when this happens, and I can reconnect, but closing the com port takes a long time after this error occurs.

Does this have to do with the temperature of the interal oscillator on the picaxe slightly changing the baud rate? Or should that not matter because I’m using the “hardware serial port” on the 18m2? What would cause the bluetooth module to intermittently disconnect like that? Does it have its own buffer getting overflowed?

Also, I have the CTS and RTS pins tied togethor on the bluetooth module. Would using RTS/CTS alleviate this problem?

Thanks for reading! I want to stop thinking about this!