.. zephyr:code-sample:: ht16k33
:name: HT16K33 LED driver with keyscan
:relevant-api: led_interface kscan_interface
Control up to 128 LEDs connected to an HT16K33 LED driver and log keyscan events.
Overview
********
This sample controls the LEDs connected to a `Holtek HT16K33`_
driver. The sample supports up to 128 LEDs connected to the
rows/columns of the HT16K33.
The LEDs are controlled using the following pattern:
1. turn on all connected (up to 128) LEDs one-by-one
2. blink the LEDs at 2 Hz, 1 Hz, and 0.5 Hz
3. reduce the brightness gradually from 100% to 0%
4. turn off all LEDs, restore 100% brightness, and start over
The sample logs keyscan events on the console.
Building and Running
********************
Build the application for the :ref:`nrf52840dk_nrf52840` board, and
connect an HT16K33 LED driver at address 0x70 on the I2C-0 bus.
.. zephyr-app-commands::
:zephyr-app: samples/drivers/ht16k33
:board: nrf52840dk/nrf52840
:goals: build
:compact:
For flashing the application, refer to the Flashing section of the
:ref:`nrf52840dk_nrf52840` board documentation.
References
**********
.. target-notes::
.. _Holtek HT16K33: http://www.holtek.com/productdetail/-/vg/HT16K33
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