Sentinel (and rEvo)

["Paul-Erik Törrönen"]

> The D<n> command is multiple bytes, right?

Yes. As I wrote, I tried the single char commands from the terminal
software, and they did not work.

> I think you are trying to re-use a bit too much from the backend that
> you used as an example. How to best read the response depends on how the
> protocol works. Is the length fixed or variable, do we known it in
> advance or not, etc.

Ok. As I may have mentioned in the beginning, this is totally unknown
territory for me. From my understanding though, the code logic should be
pretty simple: We do some base assumptions about buffer size, then attempt
to read it full, and if the data from the device i less, then we should
resize the buffer to match the actual data amount.

Going back here: When I successfully get the universal to send (even this
seems to be unstable at times) the request byte, it does receive what
seems to be an appropriate response.

But I think I understand your point, it could be that the chipset on the
USB-cable pretending to be a serial device has some assumptions when the
client is reading off it, and this has to be matched by the client
software?

FWIW is it meaningful that the portmon log seems to indicate single byte
read most of the time, or is it just an artifact of how portmon logs the
communication?

Here's a snippet of the portmon log (I grep IRP_MJ for clarity):

87      0.00000698      ProLink2010oct. IRP_MJ_READ     Silabser0      
SUCCESS Length 3: 50 50 50
92      0.00001509      ProLink2010oct. IRP_MJ_CLEANUP  Silabser0      
SUCCESS
93      0.00320152      ProLink2010oct. IRP_MJ_CLOSE    Silabser0      
SUCCESS
94      0.02598515      ProLink2010oct. IRP_MJ_CREATE   Silabser0      
SUCCESS Options: Open
121     0.00000503      ProLink2010oct. IRP_MJ_READ     Silabser0      
SUCCESS Length 1: 50
130     0.00000531      ProLink2010oct. IRP_MJ_READ     Silabser0      
SUCCESS Length 1: 50
139     0.00000531      ProLink2010oct. IRP_MJ_READ     Silabser0      
SUCCESS Length 1: 50
145     0.00093783      ProLink2010oct. IRP_MJ_WRITE    Silabser0      
SUCCESS Length 1: 4D
155     0.00000559      ProLink2010oct. IRP_MJ_READ     Silabser0      
SUCCESS Length 1: 64
164     0.00000363      ProLink2010oct. IRP_MJ_READ     Silabser0      
SUCCESS Length 1: 0D
173     0.00000363      ProLink2010oct. IRP_MJ_READ     Silabser0      
SUCCESS Length 1: 0A
182     0.00000363      ProLink2010oct. IRP_MJ_READ     Silabser0      
SUCCESS Length 1: 76

0x50 equals P and seems to be the standby byte sent periodically.

So this equals to:

read: PPP
read: P
read: P
read: P
send: M
read: d
read: \r
read: \n
read: v
...

Poltsi

-- 
Paul-Erik Törrönen   poltsi at 777-team.org
+358 40 703 1231     http://poltsi.fi/

     Science, it reduces the stupid