The previous implementation assumed that a receive data chunk ends
exactly with a sensor packet's end. Yet the buffer had 32 bytes while
the packets have 19 bytes.
Separate the data reception from the packet processing. Collect whatever
chunks the USB connection provides, and scan the resulting buffer for
packets. Cope with either incomplete or corrupt or misaligned packets as
well as with multiple packets in receive chunks. The latter might happen
upon initial synchronization, when a device already sends data or the
serial port buffered previously communicated data.
In the regular case, the computer will process so fast that each single
character will be handled individually. We don't mind. The frequency is
some 60 times per second, and the data volume is 19 bytes. The software
works for the regular case, and synchronizes fast at startup or after
comm errors.
Always print the data bytes of received buffers in the packet parser,
then check some more fixed fields to not process invalid packets, then
process the packet content as the previous implementation did.
Call the packet parser for incomplete packets and discarded input
buffers as well (initial synchronization, re-sync after comm errors).
This results in the availability of more diagnostics during development.
Pass the packet's location and size from outside. This prepares the
logic to cope with situations where the receive buffer contains multiple
(potentially incomplete) packets.
Slightly unobfuscate the UT32x packet parser. The protocol is mostly
ASCII based, checks for hex numbers may be unexpected. Use symbolic
identifiers for the packet length and some special characters.
The previous implementation of the UT32x driver expected to see a conn=
spec, without it no device is found. Default to the USB identification
of the CH9325 chip, to make the driver work out of the box. Users still
can provide conn= specs and override the default for other cables.
Slightly rephrase README.devices since there is no strict distinction
into "fully automatic" and "always manual". Some drivers _accept_ conn=
specs when provided, _and_ support automatic detection of enumerable
devices, _and_ might implement defaults but also support overrides.
Nit, numerically sort the list of Uni-T cables (which is about to grow
in the future) for improved readability.
Add two more devices which require users to manually enable the serial
communication (Brymen BM257s, EEVBlog 121GW).
Fill in the scan, open/close, get/set/list, acquisition start/stop logic
such that data acquisition with a PICkit2 works.
Trigger support needs more attention. User specified triggers either
seem to not take effect, or the trigger position is not in the expected
location. It's yet to get determined what's the issue.
This implementation is based on protocol information gathered from the
pk2-la project.
Remove a free() call in an error path for a list which immediately
before the call was determined to be NULL. Use index 0 and 1 for
channels P1 and P2 respectively (the previous implementation used 0
for both channels).
The current implementation of the SCPI DMM driver is conservative about
checking the device's being operational, but the *OPC? queries are found
in unfortunate locations. Run the OPC query right before running the
next "actual" command, not afterwards. And certainly not between sending
requests and potentially gathering responses in subsequent calls.
This commit does not change current behaviour, but improves maintenance
before pending commits.
The "get MQ" helper routine communicates SCPI responses and translates
them to internal "MQ and flag" values. Optionally return the MQ table
entry reference to callers, so they don't have to repeat the table
lookup when the function's default precision is required, or should
future "start acquisition" requests need to refer to the meter's current
function.
Supported SCPI DMM devices will differ in the set of options and whether
parameters can get queried or configured. Use a "generic" set of devopts
during scan and for simpler models, prepare support for other sets of
devopts for more complex models.
Implement the scpi-dmm driver in such a generic way that it could work
with several protocol variants and with differing models which happen to
use any of these protocol variants. Prepare a list of supported models
with their respective SCPI command set, set of DMM functions and their
precision.
Add support for Agilent 34405A. The ten functions of this device got
tested and are operational, in continuous mode as well as with sample
count or capture time limits. The driver can query the current meter's
function, can change the function, and can run acquisitions in either
the current mode or with a user specified function selection. There is
some potential for improvement: AUTO/MIN/MAX/HOLD indicators are not
supported by this implementation.
The SCPI protocol may communicate strings in quoted form, enclosed by a
matching pair of single or double quote characters, and occurances of
this very quote character within the string get doubled (escaped). Add a
common routine to undo the quotes.
Free the SCPI hardware info after successful model detection, too. Only
allocate the device instance when a supported model was found. Link the
device context earlier right after allocation, for easier verification.
The Fluke 45 probe routine tries to detect whether the serial port is
"in echo mode" (which already is questionable before the IDN query).
In the absence of a response, the library segfaults. Fix it.
==214948== 16 bytes in 1 blocks are definitely lost in loss record 161 of 6,440
==214948== at 0x4C2EE0B: malloc (vg_replace_malloc.c:299)
==214948== by 0x650F435: g_malloc (in /usr/lib64/libglib-2.0.so.0.5600.3)
==214948== by 0x6527056: g_slice_alloc (in /usr/lib64/libglib-2.0.so.0.5600.3)
==214948== by 0x65284B0: g_slist_copy_deep (in /usr/lib64/libglib-2.0.so.0.5600.3)
==214948== by 0x592BBA6: sr_session_dev_list (session.c:402)
==214948== by 0x56EF7B5: sigrok::Session::Session(std::shared_ptr<sigrok::Context>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) (classes.cpp:932)
==214948== 16 bytes in 1 blocks are definitely lost in loss record 162 of 6,440
==214948== at 0x4C2EE0B: malloc (vg_replace_malloc.c:299)
==214948== by 0x650F435: g_malloc (in /usr/lib64/libglib-2.0.so.0.5600.3)
==214948== by 0x6527056: g_slice_alloc (in /usr/lib64/libglib-2.0.so.0.5600.3)
==214948== by 0x65284B0: g_slist_copy_deep (in /usr/lib64/libglib-2.0.so.0.5600.3)
==214948== by 0x592BBA6: sr_session_dev_list (session.c:402)
==214948== by 0x56F1EB1: sigrok::Session::devices() (classes.cpp:967)
Wolfram Sang
Gerhard Sittig
Martin Ling
majekw
Mike Williams
Uwe Hermann
Paul
Daniel Anselmi
Michał Janiszewski
Sven Bursch-Osewold
Jon Burgess
Guido Trentalancia