On 01/08/2015 09:17 AM, Jean-Luc Aufranc wrote: > > On 01/08/2015 01:53 AM, Uwe Hermann wrote: >> Hi, >> >> On Wed, Jan 07, 2015 at 11:16:33AM +0700, Jean-Luc Aufranc wrote: >>> I've also taken some picture of my setup -> >>> https://picasaweb.google.com/110719562692786994119/UNITUT16E?authuser=0&feat=directlink >>> I bought the multimeter @ >>> http://www.dx.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306 >>> in October 2014. >>> lsusb for the USB to serial adapter: http://pastebin.com/KVAtJbg0 >> Aha, that's likely the problem: >> >> idVendor 0x1a86 QinHeng Electronics >> idProduct 0x7523 HL-340 USB-Serial adapter >> >> We've seen other (USBHID-to-serial) adapters from QinHeng that do >> "strange" things to the data. If you have another USB-to-serial adapter >> with an FTDI or Prolific chip I'm pretty sure it'll work fine (you >> already mentioned in another post that using a real RS232 port also >> works fine). > Another person mentioned it worked fine. I only have one USB to serial > adapter, and my computer does not have a serial port. It works in a > Windows virtual machine hosted in my Ubuntu computer, but maybe the > Windows software for UT61E handles the issue you mentioned below. >> >> >>> Output using cutecom (ttyUSB0 / 19200 7O1) with Ohm range set to >>> kOhm and >>> .0L: >>> >>> 00000000: 31 32 32 b5 38 b0 b3 31 b0 b0 b0 b0 0d 8a 31 32 >> Yep, this looks incorrect and is likely caused by the QinHeng adapter. >> >> The "0d 8a" should be "0d 0a" for example, it looks like the adapter >> messes around with the parity bit and thus breaks the protocol. >> >> There are workarounds for this, we're doing a similar thing for the >> UT-D04 cable that's shipped with some UNI-T devices, e.g. >> >> http://sigrok.org/gitweb/?p=libsigrok.git;a=blob;f=src/hardware/uni-t-dmm/protocol.c;h=37144980fa108ea13e5b880274b491e686ec47ff;hb=HEAD#l225 >> >> Not sure whether it makes sense to add a workaround for this specific >> USB-to-serial device (and where) in libsigrok. >> >> Where did you get this USB-to-serial device? Was it shipped with the >> multimeter or bought extra (and it's not intended to be used with >> this device)? > I got it separately on DealExtreme or Ebay. I'll try to purchase > another one. > > Maybe the workaround could be implement as a fallback method in case > an "Invalid function byte" is detected while using es51922. >> >> >> Uwe. > Finally, it's because ch340/ch341 driver did not support the parity bit, but somebody wrote a patch: https://github.com/karlp/linux/tree/ch341-3.18.6
I've tested it, and it works. I explain what I did @ http://www.cnx-software.com/2015/03/06/how-to-build-a-single-kernel-module-driver-in-ubuntu/ ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ sigrok-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/sigrok-devel
