From: Gerhard Sittig Date: Sat, 11 Jun 2022 14:21:40 +0000 (+0200) Subject: README.devices: explicitly discuss serial-over-HID in the UNI-T section X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=0097afa446b4d8cc2d7329b9bcdf5f76df771525;p=libsigrok.git README.devices: explicitly discuss serial-over-HID in the UNI-T section This amends commit f736691d1323. Explictly mention that USB cables for UNI-T devices and rebrands transparently work with libsigrok's serial communication over HID cables. Mention that uni-t-dmm is redundant. --- diff --git a/README.devices b/README.devices index d2f4db8c..0a4d2109 100644 --- a/README.devices +++ b/README.devices @@ -360,19 +360,27 @@ Examples (sigrok-cli): $ sigrok-cli --driver uni-t-ut61e-ser:conn=/dev/ttyUSB0 ... $ sigrok-cli --driver voltcraft-vc820-ser:conn=/dev/ttyS0 ... - -When using any of the UT-D04 USB/HID cables you have to use the respective -driver _without_ the '-ser' drivername suffix (internally all of these models -are handled by the 'uni-t-dmm' driver). - -You also need to specify the USB vendor/device IDs of the cable. -Autodetection is not possible here, since various other products use the -USB VID/PID of those cables too, and there is no way to distinguish them. - -Since the UT-D04 cables are USB based (but don't use a USB-to-serial chip) -there is no need to specify a serial port via 'conn', of course. -However, the user running the frontend does also need to have permissions -to access the respective USB device (see above). + $ sigrok-cli --driver uni-t-ut61e-ser:conn=hid/cp2110 + +Using any of the UT-D04 et al USB/HID cables can be done in two different +ways: Use transparent serial over HID support in libsigrok, by giving the +-ser driver a conn=hid/... serial port spec. This re-uses the 'serial-dmm' +driver, results in better coverage of these code paths, and reduces +maintenance overhead. Or by running non-ser drivers and passing USB +specific connection details. When the driver _without_ the '-ser' suffix +is used, the models are handled by the 'uni-t-dmm' driver. These duplicate +drivers only exist for historical reasons, the redundancy may result in +differences of behaviour between the two implementations. When in doubt, +check if the '-ser' driver works for you. + +In the USB specific driver case you need to specify the cable's vendor +and product IDs. Autodetection is not possible here, since various other +products use the USB VID/PID of those cables too, and there is no way to +distinguish them. The sigrok software errs on the safe side, and won't +communicate to serial ports unless explicitly instructed by the user. + +The user running the frontend does also need to have permissions to +access the respective USB device (see above). Examples (sigrok-cli):