4253eae005
The nRF52840 DK board target, so far known as nrf52840_pca10056, is renamed to nrf52840dk_nrf52840. Its documentation and all references to its name in the tree are updated accordingly. Overlay and configuration files specific to this board are also renamed, to match the new board name. Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>
62 lines
1.8 KiB
ReStructuredText
62 lines
1.8 KiB
ReStructuredText
.. _blink-led-sample:
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PWM: Blink LED
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##############
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Overview
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********
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This is a sample app which blinks a LED using PWM.
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The LED will start at a blinking frequency of 1 Hz. Every 4 seconds,
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the blinking frequency will double. When the blinking frequency
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reaches 64 Hz, the blinking frequency will be halved every 4 seconds
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until the blinking frequency reaches 1 Hz. This completes a whole
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blinking cycle. This faster-then-slower LED blinking cycle repeats forever.
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Since for some PWM hardware it might be not possible to set the PWM period of
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1 second (to achieve the blinking frequency of 1 Hz), this application at its
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beginning tries to determine what is available for the used PWM hardware,
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and accordingly decreases the maximum PWM period (thus increases the initial
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blinking frequency) if needed.
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Wiring
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******
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Nucleo_F401RE, Nucleo_L476RG, STM32F4_DISCOVERY, Nucleo_F302R8
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==============================================================
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Connect PWM2(PA0) to LED
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Nucleo_F103RB
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=============
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Connect PWM1(PA8) to LED
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Nucleo_L496ZG
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=============
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No special board setup is necessary because there are three on-board LEDs (red,
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green, blue) connected to the Nucleo's PWM.
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Hexiwear K64
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============
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No special board setup is necessary because there is an on-board RGB LED
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connected to the K64 PWM.
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nrf52840dk_nrf52840
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===================
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No special board setup is necessary because there is an on-board LED connected.
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Building and Running
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********************
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This sample can be built for multiple boards, in this example we will build it
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for the nrf52840dk_nrf52840 board:
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.. zephyr-app-commands::
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:zephyr-app: samples/basic/blink_led
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:board: nrf52840dk_nrf52840
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:goals: build flash
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:compact:
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After flashing the image to the board, the user LED on the board should start to
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blinking as discussed in overview
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