boards: shields: Add Adafruit HT16K33 LED matrix shield

Product photo from https://learn.adafruit.com/assets/87051
with the license CC BY-SA 3.0

Tested with the command mentioned in the index.rst page.

Signed-off-by: Jonas Berg <[email protected]>

Author: pyhys

boards/shields/adafruit_ht16k33/Kconfig.shield

@@ -0,0 +1,5 @@
+# Copyright (c) 2025 Jonas Berg
+# SPDX-License-Identifier: Apache-2.0
+
+config SHIELD_ADAFRUIT_HT16K33
+	def_bool $(shields_list_contains,adafruit_ht16k33)

boards/shields/adafruit_ht16k33/adafruit_ht16k33.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2025 Jonas Berg
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&zephyr_i2c {
+	status = "okay";
+
+	ht16k33_adafruit_ht16k33: ht16k33@70 {
+		compatible = "holtek,ht16k33";
+		reg = <0x70>;
+	};
+};

boards/shields/adafruit_ht16k33/doc/adafruit_ht16k33.webp

@@ -0,0 +1,66 @@
+.. _adafruit_ht16k33:
+
+Adafruit HT16K33 LED Matrix Shield
+##################################
+
+Overview
+********
+
+The `Adafruit Small 1.2 inch 8x8 LED Matrix with I2C Backpack`_ features
+a `Holtek HT16K33 LED Controller Driver`_, an 8x8 LED matrix and two STEMMA QT connectors.
+
+This shield definition can also be used with other shields having a HT16K33 LED
+controller. The controller exposes up to 128 LEDs, and the mapping between a LED number
+and a physical LED might differ on different shields.
+See `Discussion on other LED backpacks`_.
+
+.. figure:: adafruit_ht16k33.webp
+   :align: center
+   :alt: Adafruit 8x8 LED Matrix Shield
+
+   Adafruit 8x8 LED Matrix Shield (Credit: Adafruit)
+
+
+Requirements
+************
+
+This shield can be used with boards which provide an I2C connector, for
+example STEMMA QT or Qwiic connectors.
+The target board must define a ``zephyr_i2c`` node label.
+See :ref:`shields` for more details.
+
+
+Pin Assignments
+===============
+
++--------------+-------------------+
+| Shield Pin   | Function          |
++==============+===================+
+| SDA          | HT16K33 I2C SDA   |
++--------------+-------------------+
+| SCL          | HT16K33 I2C SCL   |
++--------------+-------------------+
+
+See :dtcompatible:`holtek,ht16k33` for documentation on devicetree settings.
+
+
+Programming
+***********
+
+Set ``--shield adafruit_ht16k33`` when you invoke ``west build``. For example
+when running the :zephyr:code-sample:`ht16k33` sample:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/ht16k33
+   :board: adafruit_qt_py_rp2040
+   :shield: adafruit_ht16k33
+   :goals: build
+
+.. _Adafruit Small 1.2 inch 8x8 LED Matrix with I2C Backpack:
+   https://www.adafruit.com/product/1632
+
+.. _Discussion on other LED backpacks:
+   https://learn.adafruit.com/adafruit-led-backpack
+
+.. _Holtek HT16K33 LED Controller Driver:
+   https://www.holtek.com/page/vg/HT16K33A

boards/shields/adafruit_ht16k33/doc/index.rst

@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: Apache-2.0
+#
+# Copyright (c) 2025, Jonas Berg
+
+shield:
+  name: adafruit_ht16k33
+  full_name: Adafruit HT16K33 LED Matrix Shield
+  vendor: adafruit
+  supported_features:
+    - led

boards/shields/adafruit_ht16k33/shield.yml

@@ -3,6 +3,10 @@ sample:
   name: HT16K33 sample
 tests:
   sample.drivers.ht16k33:
-    platform_allow: nrf52840dk/nrf52840
+    platform_allow:
+      - nrf52840dk/nrf52840
+      - adafruit_qt_py_rp2040/rp2040
+    extra_args:
+      - platform:adafruit_qt_py_rp2040/rp2040:SHIELD="adafruit_ht16k33"
     harness: TBD
     tags: LED