.. 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