The sample buffer is a still a bit of a mystery, but this should help.
The variables in play:
triggerbar/ramsize_trigger - These two variables added together indicate
how many samples we want captured. ramsize_trigger - triggerbar
indicades how many samples must be captured. The ratio between the two
is determined by capture ratio.
memory_size - This indicates the number of samples in the circular
capture buffer. stop_address, now_address, and trigger_address are
pointers within the zeroplus that wrap based on this size.
now_address - The address that the zeroplus was about to write to when
it finished capturing, and now the address that will be read from when
reads are done from the capture buffer
stop_address - The address that the zeroplus last wrote to when it
completed capture.
trigger_address - The sample address for which the trigger occured.
status - This one is a bit tricky. Some testing has shown that if the
zeroplus has captured memory_size or less samples, the STATUS_READY bit
is set. For all captures generated with more samples than this,
STATUS_READY was cleared. However, boundary conditions are difficult to
test and values such as, memory_size + 1 have not been tested. We use
this to determine if the capture has wrapped through the sample buffer.
More testing is required, but this improves behavior in a number of
cases, specifically capturing sample amounts that are not a power of 2
of the sample buffer size. Before, random data was passed to libsigrok.
Signed-off-by: Russ Dill <Russ.Dill@gmail.com>
Experimentation with the windows driver has found no situation where
this is set to anything other than 1. The zerominus software also never
sets this to anything other than one. Revert the code change made in
0ab0cb942f.
Signed-off-by: Russ Dill <Russ.Dill@gmail.com>
If there is no trigger, don't try to capture anything before it. There
won't be any because we trigger immediately.
Signed-off-by: Russ Dill <Russ.Dill@gmail.com>
This will need some additional work when support is added for compression
modes since group D is disabled for RLE compression and C and D are
disabled for "double" compression.
Signed-off-by: Russ Dill <Russ.Dill@gmail.com>
We have to wait a bit longer than 1s for a valid DMM packet to arrive,
since for various DMMs some modes (Hz/% for example) the packets will
arrive a lot less often than in other modes. If the waiting period is
too short detection of the DMM will fail.
CC libsigrok_hw_gmc_mh_1x_2x_la-protocol.lo
protocol.c:133:32: warning: equality comparison with extraneous
parentheses
[-Wparentheses-equality]
} else if ((devc->scale1000 == 2)) {
~~~~~~~~~~~~~~~~^~~~
protocol.c:133:32: note: remove extraneous parentheses around the
comparison to
silence this warning
} else if ((devc->scale1000 == 2)) {
~ ^ ~
Here is what the datasheet says about this:
"If judge bit is 1, it means frequency mode. If judge bit is 0,
it means duty cycle mode."
But this is plain wrong. Reality proves this is the other way around.
Depending on the chip, the limit value for the buzzer is between 25 and 35 Ω,
so this code set the limit for continuity to 25 Ω to be on the safe side.
Uwe Hermann
Matthias Heidbrink
Aurelien Jacobs
Russ Dill
Martin Ling
Bert Vermeulen