Define a SPI baud rate, as well as WS2812_STRIP_ONE_FRAME and
WS2812_STRIP_ZERO_FRAME values, that work for nRF5 devices.
Signed-off-by: Marti Bolivar <marti@opensourcefoundries.com>
The given defaults were chosen for 96b_carbon, which is an STM32F4X
board that supports the specified WS2812_STRIP_SPI_BAUD_RATE exactly.
Rather than assume the rest of the world works that way, guard the
Kconfig options accordingly.
This is preparation work for adding configuration for other hardware.
Signed-off-by: Marti Bolivar <marti@opensourcefoundries.com>
At least on nRF52 devices, we are taking too much time between pixels
dealing with overhead inside the SPI driver transceive calls. This is
leading to dropped frames, because the dead time between frames is
long enough (5000ns+) to look like a reset pulse to the LED strip.
Given this SPI driver limitation, it seems this LED driver's design
decision to rely on SPI peripherals as efficient pulse generators
doesn't work well in practice.
The right way to handle this is probably to switch from SPI to
efficient inline assembly which bit-bangs the pulses with interrupts
disabled.
This is what other efficient libraries do to drive this type of
LED (e.g. FastLED uses C++ templates that expand into such
assembly). The Zephyr GPIO API doesn't support doing that in a
portable fashion, unfortunately.
For now, we'll cheat by pre-allocating enough buffer space to send the
entire strip's worth of data.
This is preposterously inefficient (8x memory overhead since there's
one byte to make a SPI frame for each bit of color), but makes the
driver work correctly.
(Note that using timer peripherals as pulse generators, when combined
with DMA for efficiency, would also lead to similar levels of
overhead.)
Signed-off-by: Marti Bolivar <marti@opensourcefoundries.com>
The return of memset is never checked. This patch explicitly ignore
the return to avoid MISRA-C violations.
The only directory excluded directory was ext/* since it contains
only imported code.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
I removed GPIO configuration from board files and enabled them
as default in driver Kconfig file. All boards had GPIO ports
enabled that is why I decided to enable it by default.
Power management example was changed to use new driver.
Signed-off-by: Mieszko Mierunski <mieszko.mierunski@nordicsemi.no>
Bool symbols implicitly default to 'n'.
A 'default n' can make sense e.g. in a Kconfig.defconfig file, if you
want to override a 'default y' on the base definition of the symbol. It
isn't used like that on any of these symbols though, and is
inconsistent.
This will make the auto-generated Kconfig documentation have "No
defaults. Implicitly defaults to n." as well, which is clearer than
'default n if ...'
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
tx_bufs/tx_count and rx_bufs/rx_count can be hold in another dedicated
structure, thus reducing the number of parameters to transceive. This
permits to avoid using the stack when calling transceive.
Since we saved parameters, we can expose back the struct device pointer,
to stay consistent with other device driver APIs.
Fixes#5839
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Upcoming Nordic ICs that share many of the peripherals and architecture
with the currently supported nRF5x ones are no longer part of the nRF5
family. In order to accomodate that, rename the SoC family from nrf5 to
nrf, so that it can contain all of the members of the wider Nordic
family.
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
This driver uses a bit-banging based technique of generating a signal
for the WS2812B LED strip. Since bit-banging is very timing sensitive,
where each CPU cycle counts, the driver uses inline assembly to
perform the most critical operataions. This initial version of the
driver only supports a Cortex-M0 implementation, and can e.g. be used
with the ZIP Halo LED strip for the BBC microbit:
https://www.kitronik.co.uk/5625-zip-halo-for-the-bbc-microbit.html
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The APA102 is a RGB LED with integrated controller. LEDs can be
daisy-chained and use SPI for communication. The SPI port is
configured via Device Tree.
Tested on the Adafruit Trinket M0.
Signed-off-by: Michael Hope <mlhx@google.com>
Introducing CMake is an important step in a larger effort to make
Zephyr easy to use for application developers working on different
platforms with different development environment needs.
Simplified, this change retains Kconfig as-is, and replaces all
Makefiles with CMakeLists.txt. The DSL-like Make language that KBuild
offers is replaced by a set of CMake extentions. These extentions have
either provided simple one-to-one translations of KBuild features or
introduced new concepts that replace KBuild concepts.
This is a breaking change for existing test infrastructure and build
scripts that are maintained out-of-tree. But for FW itself, no porting
should be necessary.
For users that just want to continue their work with minimal
disruption the following should suffice:
Install CMake 3.8.2+
Port any out-of-tree Makefiles to CMake.
Learn the absolute minimum about the new command line interface:
$ cd samples/hello_world
$ mkdir build && cd build
$ cmake -DBOARD=nrf52_pca10040 ..
$ cd build
$ make
PR: zephyrproject-rtos#4692
docs: http://docs.zephyrproject.org/getting_started/getting_started.html
Signed-off-by: Sebastian Boe <sebastian.boe@nordicsemi.no>
The WS2812 LED driver IC has a one-wire interface which encodes bit
values as pulse widths.
The ICs themselves are basically shift registers. Roughly speaking, a
"short" pulse shifts in a zero bit, a "long" pulse shifts in a one
bit, and an inter-pulse gap exceeding a reset time threshold causes a
pixel to latch the shifted-in color values. Each chip has an output
pin for daisy chaining. Refer to the chip datsheets and comments in
Kconfig.ws2812 for more details.
To meet timing without hogging the core, this driver generates pulses
using SPI. To work, this requires the MOSI line to stay low between
SPI frames, and for inter-frame delays to be less than the reset pulse
time.
There are other ways do it (PWM + DMA on some SoCs, GPIO bit-banging
if no other tasks need the core), but this is a reasonably
general-purpose implementation.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
LPD880x (e.g. LPD8803, LPD8806) devices are LED driver ICs which can
be controlled via a reduced SPI interface (clock and data only), and
support daisy chaining.
Add an led_strip driver for these devices.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
This API covers drivers for strips, or strings, of individually
addressable LEDs. Both RGB and grayscale LED strip drivers can be
implemented within these APIs.
The API only provides for updating the entire strip, since not all
strips support updating individual LEDs without affecting the others.
Subsequent patches will add individual driver support.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
Kumar Gala