M2000 Tomtom 5 GPS port issue

[Guest gilbobs]

I hope someone can help with an ingenius way round this....

Im running TOMTOM 5 Navigator with a wired GPS (via com serial com1 - infra red is disabled) in conjuction with a THB universal take and talk cradle which allows handsfree for the phone. This works absolutely fine, Ive added a 1 second delay to the voice prompts to allow for the relay 'switch' delay between the audio system and the PDA (via the THB cradle), again this works fine. What I am experiencing is that after receiving a voice prompt through the audio system or end a call on the phone, TOMTOM detects no GPS signal and greys out as a result for the period where you can hear the relay switching back from the PDA to the audio system.

After further investigation, Ive ruled out the power supply for the GPS antenna as this has been measured during the problem, secondly, if you run from a Bluetooth GPS antenna there is no problem. For me, this concludes that for a brief moment when the unit is switching (approx 1 sec) the GPS com port is getting disabled for this period. Ive also now learned that this PDA uses the shares the same voice prompts and the GPS signals from the hardware.

I would serious aprreciate any help with this