zephyr

History

Steve Boylan d0aced304b drivers: spi: RPi Pico PIO SPI code size and byte order. Use minimized PIO code for 3-wire operation. Input and output buffers are conventionally stored in bus byte order. For 16 and 32 bit transfers, this is effectively big-endian, so txbuf and rxbuf need to be read as such. Those pointers also need to be declared uint8_t * instead of void *. In addition, tx_count and rx_count are based on dts, and refer to whole transfers (8, 16, or 32 bits), not bytes. Added rpi_pico.overlay to samples/sensor/magn_polling to demonstrate 32-bit word size, and updated the README.rst to make it independent of the specific sensor. Clean up compliance check failures. Fix typos. Synchronize 3-wire TX and RX cycles. Simplify state machine synchronization Minimize SPI bus delay time in 3-wire mode Move clock delay to PIO code and remove k_sleep Signed-off-by: Steve Boylan <stephen.boylan@beechwoods.com>		2024-11-16 14:00:16 -05:00
..
boards	…
src	…
CMakeLists.txt	…
README.rst	…
prj.conf	…
sample.yaml	…

README.rst

.. zephyr:code-sample:: magn_polling
   :name: Magnetometer Sensor
   :relevant-api: sensor_interface

   Get magnetometer data from a magnetometer sensor (polling mode).

Overview
********

Sample application that periodically reads magnetometer (X, Y, Z) data from
the first available device that implements SENSOR_CHAN_MAGN_* (predefined array
of device names).

Board-specific overlays
***********************

TMAG5170 via Raspberry Pi Pico
==============================

The Zephyr driver for the :dtcompatible:`ti,tmag5170`` requires an SPI driver
that supports 32-bit SPI_WORD_SIZE.  On the :zephyr:board:`rpi_pico`, the
:dtcompatible:`raspberrypi,pico-spi-pio` SPI driver provides this support,
demonstrated with the
:zephyr_file:`samples/sensor/magn_polling/boards/rpi_pico.overlay`.

The GPIO pin assignments in the overlay file are arbitrary.  The PIO SPI
driver allows using any four GPIO pins for the SPI bus.  Just keep in mind
that the pin assignments in the pinctrl block and the pio0_spi0 block
must match.

With the sensor wired to the desired pins, build and flash with:

.. zephyr-app-commands::
   :zephyr-app: samples/sensor/magn_polling
   :goals: build flash
   :board: rpi_pico