michaelh/zephyr
1
0
Fork 0
Code Releases Activity

samples/shields/x_nucleo_iks02a1: Review README file for microphone

Browse source 
Review README file adding some more comments and removing
hints which are no longer needed.

Signed-off-by: Armando Visconti <armando.visconti@st.com>
This commit is contained in:
Armando Visconti 2021-04-28 16:36:40 +02:00 • committed by Kumar Gala
commit 812b3abff7
1 changed files with 30 additions and 19 deletions
Download patch file Download diff file Expand all files Collapse all files

49
samples/shields/x_nucleo_iks02a1/microphone/README.rst
View file

@ -18,13 +18,14 @@ Requirements
************
This sample communicates over I2C with the X-NUCLEO-IKS02A1 shield
stacked on a board with an Arduino connector. The board's I2C must be
configured for the I2C Arduino connector (both for pin muxing
and device tree). See for example the :ref:`nucleo_f411re_board` board
source code:
stacked on a board with an Arduino connector.
- :zephyr_file:`boards/arm/nucleo_f411re/nucleo_f411re.dts`
- :zephyr_file:`boards/arm/nucleo_f411re/pinmux.c`
.. note::
Please note that, in order to make the shield working on top of this board,
it is needed to have SB24 and SB29 solder bridges properly closed. In this way
the PDM microphone clock and data lines get connected to SPI clock and MOSI.
Similar consideration may apply to other boards as well.
References
**********
@ -44,19 +45,18 @@ To build the sample you can use following command:
:goals: build
:compact:
Please note that, in order to make the shield working on top of this board, it is needed to have
SB24 and SB29 solder bridges properly closed. In this way the PDM
microphone clock and data lines get connected to SPI clock and MOSI.
Similar consideration may apply to other boards as well.
.. note::
One of the things that must be verified before building the sample is the I2S output clock frequency
configuration. For example, for nucleo_f441re board, we have the following shield file that
configures the I2SPLL and have a dependency on HSE/HSI:
:zephyr_file:`boards/shields/x_nucleo_iks02a1/boards/nucleo_f411re.defconfig`
In case a different board is used, one of the things that must be verified before
building the sample is the I2S output clock frequency configuration. For example,
for nucleo_f411re board, we have the following file that configures the I2SPLL and
have a dependency on HSE/HSI:
:zephyr_file:`boards/shields/x_nucleo_iks02a1/boards/nucleo_f411re.defconfig`
The user is invited to to verify which osci is configured on the used host board
defconfig file and calculate the final I2SClk frequency, e.g.
:zephyr_file:`boards/arm/nucleo_f411re/nucleo_f411re.dts`
The user is invited to to verify which osci is configured on the used host board defconfig file
and calculate the final I2SClk frequency:
:zephyr_file:`boards/arm/nucleo_f411re/nucleo_f411re_defconfig`
Sample Output
=============
@ -91,7 +91,7 @@ as a USB CDC class, and will use ``/dev/ttyACM0``
device for communication. The ``/dev/ttyACM0`` port
must be configured in raw mode to avoid having
special characters (such as :kbd:`CTRL-Z` or :kbd:`CTRL-D`)
processed or 'cooked' out.
processed and 'cooked out'.
.. code-block:: console
@ -99,10 +99,21 @@ processed or 'cooked' out.
cat /dev/ttyACM0 > /tmp/sound.raw
dos2unix -f /tmp/sound.raw
.. note:: The dos2unix command is used to recover the situation in which the character 0x0a is
.. note::
The dos2unix command is used to recover the situation in which the character 0x0a is
interpreted as NL and an 0x0d (CR) is added. If you don't remove it the audio stream would
get corrupted.
.. warning::
The /tmp/sound.raw file final size should result exactly of 32000 byte, but sometimes may
happen that 1 or 2 spurious 0x00 bytes are put at the beginning. In this case the user
may get rid of them using the following linux command (change ``skip`` value according
to number of spurious bytes to be removed):
dd if=sound.raw of=sound_clean.raw bs=1 skip=1
ASCII PCM Output
----------------