boards: shields: Add Adafruit INA237 current sensor shield

Product photo from https://learn.adafruit.com/assets/137463
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_ina237/Kconfig.shield

@@ -0,0 +1,5 @@
+# Copyright (c) 2025 Jonas Berg
+# SPDX-License-Identifier: Apache-2.0
+
+config SHIELD_ADAFRUIT_INA237
+	def_bool $(shields_list_contains,adafruit_ina237)

boards/shields/adafruit_ina237/adafruit_ina237.overlay

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2025 Jonas Berg
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&zephyr_i2c {
+	status = "okay";
+
+	/* The shunt resistor on the board is 0.015 Ohm.
+	 * The default max shunt voltage is +/-163.84 mV,
+	 * resulting in a max current range of +/-10.92 Amps.
+	 * For this particular shield is the maximum current rated as 10 A.
+	 * Calculate the current LSB value as 10/2^15 A = 305 uA.
+	 * Round the current LSB value upwards to 500 uA.
+	 */
+	adafruit_ina237: ina237@40 {
+		status = "okay";
+		compatible = "ti,ina237";
+		reg = <0x40>;
+		rshunt-micro-ohms= <15000>;
+		current-lsb-microamps = <500>;
+	};
+};

boards/shields/adafruit_ina237/doc/adafruit_ina237.webp

@@ -0,0 +1,62 @@
+.. _adafruit_ina237:
+
+Adafruit INA237 Shield
+######################
+
+Overview
+********
+
+The `Adafruit INA237 DC Current Voltage Power Monitor Sensor Shield`_ features
+a `TI INA237 current sensor`_ and two STEMMA QT connectors.
+It measures current and bus voltage.
+
+.. figure:: adafruit_ina237.webp
+   :align: center
+   :alt: Adafruit INA237 Shield
+
+   Adafruit INA237 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          | INA237 I2C SDA    |
++--------------+-------------------+
+| SCL          | INA237 I2C SCL    |
++--------------+-------------------+
+| ALRT         | INA237 ALERT out  |
++--------------+-------------------+
+
+See :dtcompatible:`ti,ina237` for documentation on how to adjust the
+devicetree file, for example to adjust the sample averaging.
+
+
+Programming
+***********
+
+Set ``--shield adafruit_ina237`` when you invoke ``west build``. For example
+when running the :zephyr:code-sample:`sensor_shell` sample:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/sensor/sensor_shell
+   :board: adafruit_qt_py_rp2040
+   :shield: adafruit_ina237
+   :goals: build
+
+.. _Adafruit INA237 DC Current Voltage Power Monitor Sensor Shield:
+   https://learn.adafruit.com/adafruit-ina237-dc-current-voltage-power-monitor
+
+.. _TI INA237 Current sensor:
+   https://www.ti.com/product/INA237

boards/shields/adafruit_ina237/doc/index.rst

@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: Apache-2.0
+#
+# Copyright (c) 2025, Jonas Berg
+
+shield:
+  name: adafruit_ina237
+  full_name: Adafruit INA237 Current Sensor Shield
+  vendor: adafruit
+  supported_features:
+    - sensor

boards/shields/adafruit_ina237/shield.yml

@@ -26,3 +26,8 @@ tests:
     extra_args: DTC_OVERLAY_FILE=fake_sensor.overlay
     integration_platforms:
       - native_sim
+  sample.sensor.shell.shields:
+    platform_allow:
+      - adafruit_qt_py_rp2040/rp2040
+    extra_args:
+      - platform:adafruit_qt_py_rp2040/rp2040:SHIELD="adafruit_ina237"