Merge branch 'maint'

Conflicts:
	host/examples/rx_samples_to_file.cpp

3 files changed, 18 insertions, 5 deletions

diff --git a/host/docs/calibration.dox b/host/docs/calibration.dox
index 603ae22e4..eecb7af5c 100644
--- a/host/docs/calibration.dox
+++ b/host/docs/calibration.dox
@@ -57,15 +57,23 @@ daughterboard's EEPROM: :
 
 \subsection calibration_data Calibration Data
 
-Calibration files are stored in the user's home/application directory.
-They can easily be moved from machine to another by copying the "cal"
-directory. Re-running a calibration utility will replace the existing
-calibration file. The old calibration file will be renamed so it may be
-recovered by the user.
+By default, calibration files are stored in the user's home/application
+directory:
 
 -   **Linux:** `${HOME}/.uhd/cal/`
 -   **Windows:** `%APPDATA%\.uhd\cal\`
 
+If you would like to specify a custom directory, you can do so with the
+`$UHD_CONFIG_DIR` environment variable:
+
+-   **Custom (any OS):** `${UHD_CONFIG_DIR}/.uhd/cal/`
+
+Calibration files can easily be moved from one machine to another by copying the
+"cal" directory. Re-running a calibration utility will replace the existing
+calibration file. The old calibration file will be renamed so it may be
+recovered by the user.
+
+
 \subsection ignore_cal_file Ignoring Calibration Files
 
 At runtime, the user can choose to ignore a daughterboard's calibration file by adding "ignore-cal-file" to the arguments. With the UHD API, it can be done as follows:
diff --git a/host/docs/res/TRRS.png b/host/docs/res/TRRS.png
new file mode 100755
index 000000000..78619c869
--- /dev/null
+++ b/host/docs/res/TRRS.png
diff --git a/host/docs/usrp_e3x0.dox b/host/docs/usrp_e3x0.dox
index 68ffc0122..b55fa1054 100644
--- a/host/docs/usrp_e3x0.dox
+++ b/host/docs/usrp_e3x0.dox
@@ -362,6 +362,11 @@ For more advanced IMU based applications please refer to the <a href="https://gi
 Please see the \ref page_gpio_api for information on configuring and using the GPIO bus.
 
 \subsection e3x0_hw_audio Audio connectors
+The E3x0 2.5 mm Audio Jack TRRS pins are assigned as follows: Tip=Mic, Ring1=Right, Ring2=Left, Sleeve=GND. 
+
+\image html TRRS.png "Audio Jack"
+
+The Left/Right audio outputs are compatible with typical low-impedance headphones (16 to 32 Ohms). The Microphone pin provides approximately 2 mA bias at 2.2 V when not suspended. A variety of pin configurations can be found on commonly available headsets, so an adapter may be required.
 
 \subsection e3x0_hw_chipscope Debugging custom FPGA designs with Xilinx Chipscope