Hi again, 

Sorry for not getting back on this, internet down here has been a bit shady. 

Ehm, I did some tests with the dive computer and the pc interface from another computer and LogTRAK and I had the same problem there. So while it seems weird, it actually looks like my new hardware is broken. I'll have to check it with Scubapro when I get back home.

Thanks for taking the time and explaining how it works though, it makes sense now. 

Best regards, 
Patrik Martinsson, 
Sweden (Malaysia)



On Wed, Jul 15, 2015 at 9:34 AM, Jef Driesen <jef@libdivecomputer.org> wrote:
On 14-07-15 17:27, Patrik Martinsson wrote:
I'm trying to get my "Scubapro Chromis" to work with "libdivecomputer", but it
doesn't seem to work.
Is this tested with a real "Scubapro Chromis" or is the support "just added on
belief that it should work" (I noticed that the support was added a couple of
months ago for the Chromis) ?

 The rule of thumb is that a device only gets added to the list of supported devices if I receive data from at least one successful download. But for the Chromis, the only information I got is the new model number, and that the communication protocol and data format should be identical to the Meridian.

So it should work, but in this particular case I can't guarantee completely.

This is what I get when I try to dump the memory from the Chromis,

./universal -n "Scubapro Chromis" -b "meridian" /dev/ttyUSB0

 You forgot the "-v" to enable a more verbose log with the I/O. But no worries, I already got that from your post to the subsurface mailinglist :-)

DATETIME 2015-07-14T14:07:51Z (1436882871)
VERSION 0.5.0-devel (0158739bcff3c4c3f8944e6e06932d836821cf28)
Opening the device (Scubapro Chromis, /dev/ttyUSB0).
ERROR: Failed to receive the header. [in uwatec_meridian.c:111
(uwatec_meridian_transfer)]
Registering the event handler.
Registering the cancellation handler.
Downloading the memory dump.
Event: progress 0.00% (0/4294967295)
ERROR: Failed to receive the header. [in uwatec_meridian.c:111
(uwatec_meridian_transfer)]
universal.c:795: Error downloading the memory dump.
Result: Timeout

I would be surpriced if there was something wrong with the watch, however that
is of course possible.

Looking at the code I can see that there is an "echo" that is being received
before the header, so something is going on right (or am I missing something) ?

 You receive only the echo, but not the actual data packet. Echo's are often generated by the electronics in the PC interface, and not send by the dive computer. You can easily verify this by trying to download without the dive computer attached, only the PC interface. If you still receive the echo's, then they are not send by the dive computer.

Anyway, the important part is that the presence of the echo does not indicate there is some communication going on.

Have you ever tried to download your Chromis with the official Scubapro software (LogTRAK)? If not, can you try this? If that works, then we can already rule out hardware and driver problems. Next, try libdivecomputer's universal tool again on the exact same setup where you tried LogTRAK.

Jef