samples: drivers: ht16k33: add sample application for the HT16K33

Add a sample application for showcasing the functionality of the
Holtek HT16K33 LED driver with keyscan functionality.

Signed-off-by: Henrik Brix Andersen <henrik@brixandersen.dk>

CODEOWNERS

@@ -246,6 +246,7 @@
 /samples/boards/intel_s1000_crb/          @sathishkuttan @dcpleung @nashif
 /samples/display/                         @vanwinkeljan
 /samples/drivers/CAN/                     @alexanderwachter
+/samples/drivers/ht16k33/                 @henrikbrixandersen
 /samples/gui/                             @vanwinkeljan
 /samples/net/                             @jukkar @tbursztyka @pfalcon
 /samples/net/dns_resolve/                 @jukkar @tbursztyka @pfalcon

samples/drivers/ht16k33/CMakeLists.txt

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.13.1)
+
+include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
+project(ht16k33)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})

samples/drivers/ht16k33/README.rst

@@ -0,0 +1,42 @@
+.. _ht16k33:
+
+HT16K33 LED driver with keyscan
+###############################
+
+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:`nrf52840_pca10056` board, and
+connect a HT16K33 LED driver at address 0x70 on the I2C-0 bus.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/ht16k33
+   :board: nrf52840_pca10056
+   :goals: build
+   :compact:
+
+For flashing the application, refer to the Flashing section of the
+:ref:`nrf52840_pca10056` board documentation.
+
+References
+**********
+
+.. target-notes::
+
+.. _Holtek HT16K33: http://www.holtek.com/productdetail/-/vg/HT16K33

samples/drivers/ht16k33/nrf52840_pca10056.overlay

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2019 Henrik Brix Andersen <henrik@brixandersen.dk>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&i2c0 {
+	clock-frequency = <I2C_BITRATE_STANDARD>;
+
+	ht16k33@70 {
+		compatible = "holtek,ht16k33";
+		reg = <0x70>;
+		label = "HT16K33";
+                /* Uncomment to use IRQ instead of polling: */
+		/* irq-gpios = <&gpio1 8 (GPIO_PUD_PULL_UP | GPIO_INT_ACTIVE_LOW)>; */
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ks@0 {
+			compatible = "holtek,ht16k33-keyscan";
+			reg = <0x0>;
+			label = "KS0";
+		};
+		ks@1 {
+			compatible = "holtek,ht16k33-keyscan";
+			reg = <0x1>;
+			label = "KS1";
+		};
+		ks@2 {
+			compatible = "holtek,ht16k33-keyscan";
+			reg = <0x2>;
+			label = "KS2";
+		};
+	};
+};

samples/drivers/ht16k33/prj.conf

@@ -0,0 +1,6 @@
+CONFIG_LOG=y
+CONFIG_I2C=y
+CONFIG_GPIO=y
+CONFIG_LED=y
+CONFIG_HT16K33=y
+CONFIG_HT16K33_KEYSCAN=y

samples/drivers/ht16k33/sample.yaml

@@ -0,0 +1,7 @@
+sample:
+  description: Demonstration of the HT16K33 LED driver with keyscan
+  name: HT16K33 sample
+tests:
+  sample.driver.ht16k33:
+    platform_whitelist: nrf52840_pca10056
+    tags: LED

samples/drivers/ht16k33/src/main.c

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2019 Henrik Brix Andersen <henrik@brixandersen.dk>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <device.h>
+#include <led.h>
+#include <gpio.h>
+#include <zephyr.h>
+
+#define LOG_LEVEL CONFIG_LOG_DEFAULT_LEVEL
+#include <logging/log.h>
+LOG_MODULE_REGISTER(main);
+
+#define LED_DEV_NAME DT_HOLTEK_HT16K33_0_LABEL
+#define KS0_DEV_NAME DT_HOLTEK_HT16K33_KEYSCAN_0_LABEL
+#define KS1_DEV_NAME DT_HOLTEK_HT16K33_KEYSCAN_1_LABEL
+#define KS2_DEV_NAME DT_HOLTEK_HT16K33_KEYSCAN_2_LABEL
+
+#define KEYSCAN_DEVICES 3
+
+struct device *led_dev;
+struct device *ks_dev[KEYSCAN_DEVICES];
+static struct gpio_callback ks_cb[KEYSCAN_DEVICES];
+
+static void keyscan_callback(struct device *gpiob,
+			     struct gpio_callback *cb, u32_t pins)
+{
+	LOG_INF("%s: 0x%08x", gpiob->config->name, pins);
+}
+
+void main(void)
+{
+	int err;
+	int i;
+
+	/* LED device binding */
+	led_dev = device_get_binding(LED_DEV_NAME);
+	if (!led_dev) {
+		LOG_ERR("LED device %s not found", LED_DEV_NAME);
+		return;
+	}
+
+	/* Keyscan device bindings */
+	ks_dev[0] = device_get_binding(KS0_DEV_NAME);
+	ks_dev[1] = device_get_binding(KS1_DEV_NAME);
+	ks_dev[2] = device_get_binding(KS2_DEV_NAME);
+	for (i = 0; i < ARRAY_SIZE(ks_dev); i++) {
+		if (!ks_dev[i]) {
+			LOG_ERR("KS%d device not found", i);
+			return;
+		}
+
+		gpio_init_callback(&ks_cb[i], &keyscan_callback,
+				   GENMASK(12, 0));
+
+		err = gpio_add_callback(ks_dev[i], &ks_cb[i]);
+		if (err) {
+			LOG_ERR("Failed to add KS%d GPIO callback (err %d)", i,
+				err);
+			return;
+		}
+	}
+
+	while (1) {
+		LOG_INF("Iterating through all LEDs, turning them on "
+			"one-by-one");
+		for (i = 0; i < 128; i++) {
+			led_on(led_dev, i);
+			k_sleep(100);
+		}
+
+		for (i = 500; i <= 2000; i *= 2) {
+			LOG_INF("Blinking LEDs with a period of %d ms", i);
+			led_blink(led_dev, 0, i / 2, i / 2);
+			k_sleep(10 * i);
+		}
+		led_blink(led_dev, 0, 0, 0);
+
+		for (i = 100; i >= 0; i -= 10) {
+			LOG_INF("Setting LED brightness to %d%%", i);
+			led_set_brightness(led_dev, 0, i);
+			k_sleep(1000);
+		}
+
+		LOG_INF("Turning all LEDs off and restoring 100%% brightness");
+		for (i = 0; i < 128; i++) {
+			led_off(led_dev, i);
+		}
+		led_set_brightness(led_dev, 0, 100);
+	}
+}