Driver for HD44780 LCDs (#246)

Driver for HD44780 LCDs connected directly to GPIO / to I2C by PCF8574-like GPIO expanders (#246)

examples/hd44780_lcd/Makefile

@@ -0,0 +1,6 @@
+PROGRAM = hd44780_lcd
+EXTRA_COMPONENTS = extras/hd44780
+
+HD44780_I2C = 0
+
+include ../../common.mk

examples/hd44780_lcd/main.c

@@ -0,0 +1,62 @@
+/*
+ * Example of using HD44780 driver with LCD
+ * connected directly to GPIO pins
+ *
+ * Part of esp-open-rtos
+ * Copyright (C) 2016 Ruslan V. Uss <unclerus@gmail.com>
+ * BSD Licensed as described in the file LICENSE
+ */
+#include <esp/uart.h>
+#include <espressif/esp_common.h>
+#include <stdio.h>
+
+#include <hd44780/hd44780.h>
+
+static const uint8_t char_data[] = {
+    0x04, 0x0e, 0x0e, 0x0e, 0x1f, 0x00, 0x04, 0x00,
+    0x1f, 0x11, 0x0a, 0x04, 0x0a, 0x11, 0x1f, 0x00
+};
+
+void user_init(void)
+{
+    uart_set_baud(0, 115200);
+    printf("SDK version:%s\n", sdk_system_get_sdk_version());
+
+    hd44780_t lcd = {
+        .font = HD44780_FONT_5X8,
+        .lines = 2,
+        .pins = {
+            .rs = 5,
+            .e  = 4,
+            .d4 = 0,
+            .d5 = 2,
+            .d6 = 14,
+            .d7 = 12,
+            .bl = HD44780_NOT_USED
+        }
+    };
+
+    hd44780_init(&lcd);
+    hd44780_upload_character(&lcd, 0, char_data);
+    hd44780_upload_character(&lcd, 1, char_data + 8);
+
+    hd44780_gotoxy(&lcd, 0, 0);
+    hd44780_puts(&lcd, "\x08 Hello world!");
+    hd44780_gotoxy(&lcd, 0, 1);
+    hd44780_puts(&lcd, "\x09 ");
+
+    char time[16];
+
+    while (true)
+    {
+        hd44780_gotoxy(&lcd, 2, 1);
+
+        snprintf(time, 7, "%u     ", sdk_system_get_time() / 1000000);
+        time[sizeof(time) - 1] = 0;
+
+        hd44780_puts(&lcd, time);
+
+        for (uint32_t i = 0; i < 1000; i++)
+            sdk_os_delay_us(1000);
+    }
+}