The Brymen BM86x supports up to two temperature probes. The dual display
can show individual temperatures of the two probes or differences. The
previous implementation "detected" a value of zero degrees when no probe
was attached and the display showed dash lines. When cycling assignments
of probes to displays, some valid combinations did not result in values
shown by the libsigrok driver.
An implementation detail of the formerly separate brymen-bm86x driver
was lost during recent migration of the dmm/bm86x parser into the
serial-dmm driver. When the meter's temperature function is selected,
it's essential to inspect the primary display's flags and digits, to
determine the secondary display's quantity and unit. Previous versions
never bothered to explicitly check for the "----" digits text, but the
combination of the primary's last digit showing C/F as well as the
binary C/F flags before the value provided hints which the secondary
displays group of digits and flags did not.
This fixes bug #1394.
When the list of all connections gets created which are supported by the
HID serial transport, items contain a "hid/ch9325/raw=/dev/hidraw3" path
and a "1a86:e008" pair of vendor and product IDs.
Separate the VID/PID pair by a period not a colon, so that --list-serial
output immediately becomes usable with "--driver <name>:conn=<spec>"
invocations. Eliminate the necessity to adjust clipboard context by the
user. This improves usability in cases where not a single connection
gets addressed, but a group of connections gets specified by ambiguous
conn= specs.
$ sigrok-cli -d uni-t-ut32x:conn=1a86.e008 --scan
Some meters require the reception of a request before they provide
acquisition data. Add support for the chip driver's .packet_request()
routine, and timeout handling in the serial-lcr driver. This follows
the serial-dmm model.
Allow LCR chip drivers to specify custom printf() formats for their
channel names. Default to "P1" etc in the absence of format specs.
This implementation is similar to serial-dmm.
The EEVBlog 121GW meter support always registers the three-displays
parse routine with the serial-dmm device driver. The single-display
routine need not be public. Adjust the visibility.
Reduce indentation for a continued line in a nearby declaration
while we are here.
Bug #1390 reports that "!desc" is always true (should be: false?). But
the actual problem would be that 'desc' is _not_ NULL when none of the
supported chips' VID:PID matched (FT232H happens to "get found" then,
erroneously).
Add a sentinel to the table of supported chips, such that 'desc' becomes
NULL upon mismatch, and the error path is entered.
The serial-dmm entry for Victor DMMs is able to communicate to either
geniune COM ports (RS232 or USB CDC) or the obfuscating USB HID cables.
The victor-dmm driver became obsolete and was removed. Rename the
serial-dmm entry, remove the no longer needed "-ser" suffix. Suggest a
default connection via the obfuscating USB HID cable, accept user
provided overrides for regular serial cables (same behaviour as before,
connection spec for serial ports keeps being mandatory).
Remove the victor-dmm device driver. Its functionality is contained in
the Victor specific serial-over-HID transport, the FS9922 DMM parser,
and the serial-dmm device driver. The additional implementation became
obsolete.
Introduce a serial transport which undoes the Victor DMM cable's
obfuscation to the DMM chip's original data packet. Which allows to
re-use the existing FS9922 support code, obsoleting the victor-dmm
device driver.
This undoes the essence of commit bf700f679a, which introduced the
default conn= spec. Which improved usability: Users just select the
device and need not specify the connection. But also resulted in the
UT32x thermometer driver's probe to "succeed" as soon as the WCH CH9325
chip was found, no data check was involved in the scan. Unfortunately
this chip is also used in the popular UT-D04 cable, and thus there were
many false positives.
Remove the src/hardware/brymen-bm86x/ hierarchy of source files. Its
functionality has moved to the bm86x packet parser and the serial-dmm
device driver.
Request packets from the Brymen BM86x meter much faster. The previous
implementation in the separate driver used to immediately send another
request when a measurement arrived, with a 10ms granularity in the poll
routine, and a 500ms timeout between requests.
Considering the meter's update rate, stick with the 500ms timeout, but
increase the maximum request rate to 10 per second, with a minimum of 2
per second. This receives measurement data at the meter's capability
(compare DC and AC modes, seems to automatically adjust to the internal
operation, and match the display update rate).
Move Brymen BM86x specific packet parse logic to a new src/dmm/bm86x.c
source file, and register the routines with the serial-dmm driver's list
of supported devices. Which obsoletes the src/hardware/brymen-bm86x/
hierarchy.
This implementation differs from the previous version: The parse routine
gets called multiple times after one DMM packet was received. Values for
the displays get extracted in separate invocations, the received packet
is considered read-only. Unsupported LCD segment combinations for digits
get logged. Low battery gets logged with higher severity -- the validity
of measurement values is uncertain after all. The parse routine uses
longer identifiers. Packet reception uses whichever serial transport is
available (need no longer be strictly USB HID nor libusb based). All
features of the previous implementation are believed to still be present
in this version.
This configuration queries measurement values each 0.5 seconds and
re-sends a not responded to request after 1.5 seconds. Which follows the
combination of the vendor's suggested flow (frequency) and the previous
implementation's timeout (3x 500ms). This implementation does not try to
re-connect to the HID device for each measurement, and neither checks
for the 4.0 seconds timeout (vendor's suggested flow). Local experiments
work without these.
The src/hardware/brymen-bm86x/ source code contains specific support for
the Brymen BM86x devices, and directly depends on the libusb library.
Rename the registered device (append the "-usb" suffix) before adding
BM86x support to the serial-dmm driver.
The Brymen BU-86X infrared adapters are sold with BM869s meters. Raw
streams of data bytes get communicated by means of HID reports with
report number 0 and up to 8 data bytes each. Communication parameters
are fixed and need no configuration.
Some meters which are supported by the serial-dmm driver don't strictly
require the user's COM port specification. When a known (usually bundled,
or even builtin) cable type is used, we can provide a default conn= spec
and thus improve usability. Prepare the DMM_CONN() macro, accept user
overrides.
The 'conn' field in the device context and the CONN values in the
declarations of supported DMM models seemed inappropriate. They specify
the communication parameters (UART frame format and bitrate), not the
connection (port name). Adjust the respective identifiers.
Also rephrase the evaluation logic. Instead of checking for the absence
of user specs and optionally assigning a fallback value, just preset
from defaults and override from user specs when present. This simplifies
the logic (eliminates a check).
Keep the ES51919 chip support in the src/lcr/ directory, and move device
driver specific code to the src/hardware/serial-lcr/ directory. Implement
the same driver layout for LCR meters as is used for DMM devices.
This also addresses a few issues in the serial-lcr driver: Unbreak --get
and --show, do process a few LCR packets after probing the device, to
gather current parameter values. Keep sending meta packets when these
parameters change during acquisition, like the previous implementation
did. Use common code for frame/time limits.
Note that although LCR meters usually operate with AC to classify L/C/R
components, one of the officially supported modes is DC resistance.
Which means that an output frequency of 0 is not just a fallback when
packet parsing fails, it's also a regular value of the freq parameter.
List all supported frequencies including DC in strict numerical order.
Although all currently supported devices use the same ES51919 chip, the
implementation is prepared to support other devices which use different
LCR meter chips as well. The list of known equivalent circuit models and
output frequencies is kept in src/lcr/ chip support. It's assumed that
one LCR packet communicates the data for all channels/displays similar
to the serial-dmm driver implementation.
The serial communication timing parameters during probe get determined
from earlier serial port configuration, which obsoletes the redundant
'baudrate' parameter, and eliminates potential inconsistency between
user specified parameters and builtin default values.
The serial communication timing parameters during probe get determined
from earlier serial port configuration, which obsoletes the redundant
'baudrate' parameter, and eliminates potential inconsistency between
user specified parameters and builtin default values.
The serial_stream_detect() routine needs to estimate the time which is
needed to communicate a given amount of data. Since the serial port got
opened and configured before, the serial communication parameters are
known, and callers need not redundantly specify the bit rate.
The previous implementation provided a raw input stream of RX data from
read() calls to device drivers. This works great with genuine COM ports,
as well as with most setups which involve simple "cable expanders".
Recent additions of alternative transports (serial over HID and BLE)
added more protocol layers to the setup, and some device drivers are
reported to depend on the very framing of these transports: Mooshimeter
cares about individual BLE notification "frames", and the information
cannot get derived from the payload bytes. Some HID based cables which
obscure the DMM chips' serial protocol, or some HID based setups which
the serial layer does not abstract away as "a cable" may suffer from
similar requirements (do some drivers require access to individual HID
reports? Ikalogic? Victor DMM?).
Add support for an optional "RX chunk callback" which takes precedence
over "mere payload byte streams". Instead of returning payload bytes
from read() calls, the serial layer can call an application defined
routine and pass data bytes in the very framing which the physical
transport happens to use.
It's still up to the implementation of the specific transport whether
the callback approach is supported, and whether the wire's framing is
obeyed or whether payload data keeps getting provided as one raw stream.
It's also implementation dependent whether data reception transparently
occurs in background, or whether callers need to periodically "stimulate"
data reception by calling read or check routines which happen to call
back into the caller should RX data become available.
The approach that got implemented here is not universally applicable,
but serves those specific environments that were identified so far.
The CP210x USB to UART bridge is not specific to CEM DT-8852, it's a
generic bridge chip that is also used in other cables and devices. Add
the CP2110 USB HID to UART bridge that is found in UNI-T cables and
devices, and reported to also be used in Voltcraft devices.
WCH CH9325 and SiL CP2110 chips (and other HID cables) won't match the
currently used 'usb' subsystem when the platform registers these as
'hidraw' devices. Adjust the 60-libsigrok.rules SUBSYSTEM condition.
Add more examples of conn= specs for HID and Bluetooth devices to the
section which discusses COM ports. Outline the formal syntax and its
optional fields. Discuss how colons in device addresses interfere with
"-d <drv>:conn=<spec>" environments.
Introduce the serial_bt.c source file which implements the methods of a
serial transport and calls into the platform agnostic src/bt/ support
code.
Implement support for several chips and modules: RFCOMM (BT classic,
tested with HC-05), BLE122 (tested with 121GW), Nordic nRF51, and TI
CC254x (the latter untested). Read support is assumed to be complete,
write support for BLE may be incomplete due to lack of access to
hardware for tests.
Create a src/bt/ subdirectory for source files. Declare a platform
agnostic internal API for Bluetooth communication, and provide an
implementation of that portable API when the BlueZ library is available.
This implementation assumes that HAVE_BLUETOOTH and HAVE_LIBBLUEZ can be
used interchangeably, which is true for this initial version. When
support for other platforms gets added, the common and the specific
parts need to get sorted. Trying that now would involve guessing. :)
Uwe Hermann
Gerhard Sittig
Daniel Anselmi