good news on nearly all the issues of my last posting.
It seemed that my BT dongle (Belkin F8T016ng with Broadcom chipset) has been too new for the bluez 3.xx drivers. It did work but apparently not stable enough. hciconfig -a issued an input/output error after system (re)start and required a "sudo hciconfig hci0 reset" in order to reset it. While this fixed the access problem (hciconfig -a succeededl), some further hidden problems were probably causing the SCO losses.
I switched back to an older (and more common) Belkin F8T012 dongle (BCM as well) which worked out of the box. Interestingly, all the microphone problems have disappeared and voice is now true duplex. There still a little echo which may need some further dsp tuning.
Next, I compiled and ran hfstandalone. First, the link broke immediately after the connection had been established (before any call was possible). I cleaned up everything and set LD_RUN_PATH to /usr/local/lib where libspeexdsp is installed (does not yet come with Ubuntu 8.04) and re-compiled. Now the app's initilization was successful.
However, shortly after a call was established, the connection dropped out again:
It's strange so far as I do not observe this error from hfconsole.
Read from RFCOMM socket: Software caused connection abort
Involuntary device disconnect!
HCI socket read error: Broken pipe
Bluetooth Failure, hub shut down
SCO MTU: 64:8 Voice: 0x0060
Destroying record for Nokia 6310i
I don't think that it might be due to the dongle again, but it would anyhow be worthwhile trying a dongle with a different chipset (preferably CSR Bluecore 4). Do you have any recommendations? According to your sourceforge page, the CSR chipset seems to be the most stable and reliable one.
Thanks a lot!