On a sidenote, in firmware 1.6.0 there seems to be a problem with GPS/GPRS tunneling (from my point of view). Once the gpstunnel is enabled the device won't boot anymore after flashing the firmware. The solution seemed to be removing the while(1) loops in both gpstunnel and gprstunnel statements. After that I do receive GPS data via RS232 (0 satelites according to data however), but now the GPS led will stop blinking green and becomes red (hence the 0 satelites). When the tunnel is disabled the device blinks green again indicating it has valid GPS data. Is this related to the problem you mentioned?
yes it is right that the system is hold when you enable the tunnel. But be careful with removing the while(1) loops. If you do so, the gps-Task or the gprs-Task have to share all incoming characters with this tunnel. So non of them will work correctly. What now happens is, that the gps-Task doesn't get any characters. It seams for him that the GPS-Modem is dead (LED is red no blinking).
Yes I assumed that's what happend when removing the while(1) loop. However, if I understand correctly the GPS and/or GPRS data should be tunneled to UART3. When I connect HTerm it shows the system booted and then the system immediately goes offline. No more message is received nor does it show any activity on the hardware. Do I misunderstand 'tunneling' or should it actually send GPS data via UART3 to for example HTerm.
I have just moved your new question to a new topic.
Please don't mix up the debug system and the possibility to get all characters from GPS or GPRS. With the debug system it is possible to change the GPRS-Connection data and show your actual GPS-Position. Just press ?<cr><lf> to see what is possible.
The tunnel was just build in to give an very easy possibility to communicate with the GPS receiver and the GPRS-Modem.