Downloading FTDI dive log using desktop Subsurface on Android

[Willem Ferguson]

I am working with the Android version of Subsurface desktop and 
attempting download of dive logs from a FTDI dive computer.

Hardware issues:

Firstly, the Tusa does not turn into PC download mode if the USB bus 
does not supply power. Possibly on this phone the mini-USB plug does not 
supply power to devices. Therefore, connect the Android USB plug to a 
USB hub that supplies power to all connected devices. This connection 
actually is via mini-USB to full-sized US cable, through a female/female 
USB adaptor-plug and another cable to the USB hub. The Tusa DC USB plug 
is plugged into the USB hub via yet another cable. With this setup, at 
least, the Tusa DC goes into download mode.

Secondly tested most of this cable setup by download onto the Linux 
desktop using the custom FTDI driver and using the USB hub to supply 
power to the Tusa DC. Download works perfectly (i.e. with some 
ideosyncracies that Anton has already seen, dealing with cylinder gas 
composition, maybe a libdivecomputer issue. These are not relevant now). 
Fact is download works well onto Linux.

Android driver configuration:

When downloading dives onto the Anfroid device, I get an error message 
"Insufficient privileges to open the device ftdi Tusa (Zen (IQ-900))". 
This is the same error message that I get if downloading to Linux and I 
have not chown-ed the USB port or I did not build Subsurface-desktop 
with -DFTDISUPPORT=ON on the cmake command line. This does not 
necessarily mean that on Android it is exactly the same reason as on 
Linux. In android/build.sh, it looks like FTDISUPPORT is pretty much 
hard-wired into the cmake command line. Possibly the Android port also 
needs some configuration, for instance performed using chown on Linux?

Any comments?

Kind regards,

willem