doc: mention serial-over-HID in README.devices (UT-D09 cable)

diff --git a/README.devices b/README.devices
index 01baf4da79901b6d1031955d4f1e18617a7beca0..a0b2fa4ed1bb66eaaa73d275dd668a7f532e9b57 100644 (file)
--- a/README.devices
+++ b/README.devices
@@ -130,7 +130,11 @@ Specifying serial ports
 -----------------------
 
 Many devices supported by libsigrok use serial port based cables (real RS232
-or USB-to-serial ones) to connect to a PC.
+or USB-to-serial ones, CDC class) to connect to a PC. These serial cables are
+supported by the libserialport library. Some vendors prefer to use HID chips
+instead of CDC chips in their serial cables. These cables can get supported
+by means of the hidapi library. Note that each chip type requires specific
+support in the libsigrok library.
 
 For all these devices, you need to specify the serial port they are connected
 to (e.g. using the 'conn' option in sigrok-cli). It is not possible to scan
@@ -139,6 +143,7 @@ for such devices without specifying a serial port.
 Example:
 
  $ sigrok-cli --driver <somedriver>:conn=/dev/ttyUSB0 ...
+ $ sigrok-cli --driver <somedriver>:conn=hid/cp2110 ...
 
 The following drivers/devices require a serial port specification. Some of
 the drivers implement a default for the connection. Some of the drivers
@@ -290,6 +295,7 @@ ship with different PC connectivity cables:
  - UT-D02 (RS232 cable)
  - UT-D04 (USB/HID cable with Hoitek HE2325U chip, USB VID/PID 04fa:2490)
  - UT-D04 (USB/HID cable with WCH CH9325 chip, USB VID/PID 1a86:e008)
+ - UT-D09 (USB/HID cable with SiL CP2110 chip, USB VID/PID 10c4:ea80)
 
 The above cables are all physically compatible (same IR connector shape)
 with all/most currently known UNI-T multimeters. For example, you can