Added sntp support and example

examples/sntp/Makefile

@@ -0,0 +1,6 @@
+# Makefile for the sntp_example program
+
+PROGRAM=sntp_example
+EXTRA_COMPONENTS = extras/sntp
+
+include ../../common.mk

examples/sntp/sntp_example.c

@@ -0,0 +1,108 @@
+/*
+ * Test code for SNTP on esp-open-rtos.
+ *
+ * Jesus Alonso (doragasu)
+ */
+#include <espressif/esp_common.h>
+#include <esp/uart.h>
+
+#include <string.h>
+#include <stdio.h>
+
+#include <FreeRTOS.h>
+#include <task.h>
+
+#include <lwip/err.h>
+#include <lwip/sockets.h>
+#include <lwip/sys.h>
+#include <lwip/netdb.h>
+#include <lwip/dns.h>
+
+#include <ssid_config.h>
+
+// Add extras/sntp component to makefile for this include to work
+#include <sntp.h>
+
+#define SNTP_SERVERS 	"0.pool.ntp.org", "1.pool.ntp.org", \
+						"2.pool.ntp.org", "3.pool.ntp.org"
+
+#define vTaskDelayMs(ms)	vTaskDelay((ms)/portTICK_RATE_MS)
+#define UNUSED_ARG(x)	(void)x
+
+// Use GPIO pin 2
+const int gpio_frc2 = 2;
+// 1 Hz blink frequency
+const int freq_frc2 = 1;
+
+void SntpTsk(void *pvParameters)
+{
+	char *servers[] = {SNTP_SERVERS};
+	UNUSED_ARG(pvParameters);
+
+	// Wait until we have joined AP and are assigned an IP
+	while (sdk_wifi_station_get_connect_status() != STATION_GOT_IP) {
+		vTaskDelayMs(100);
+	}
+
+	// Start SNTP
+	printf("Starting SNTP... ");
+	sntp_set_update_delay(1*60000);
+	sntp_initialize(1, 0);
+	sntp_set_servers(servers, sizeof(servers) / sizeof(char*));
+	printf("DONE!\n");
+	while(1) {
+		vTaskDelayMs(5000);
+		time_t ts = sntp_get_rtc_time(NULL);
+		printf("TIME: %s", ctime(&ts));
+	}
+}
+
+void frc2_interrupt_handler(void)
+{
+    /* FRC2 needs the match register updated on each timer interrupt */
+    timer_set_frequency(FRC2, freq_frc2);
+    gpio_toggle(gpio_frc2);
+}
+
+// Configure FRC2 to blink the LED. I'm messing with FRC2 just to test if
+// it does affect FreeRTOS.
+void Frc2Config(void) {
+    /* configure GPIO */
+    gpio_enable(gpio_frc2, GPIO_OUTPUT);
+    gpio_write(gpio_frc2, 1);
+
+    /* stop timer and mask its interrupt as a precaution */
+    timer_set_interrupts(FRC2, false);
+    timer_set_run(FRC2, false);
+
+    /* set up ISR */
+    _xt_isr_attach(INUM_TIMER_FRC2, frc2_interrupt_handler);
+
+    /* configure timer frequency */
+    timer_set_frequency(FRC2, freq_frc2);
+
+    /* unmask interrupt and start timer */
+    timer_set_interrupts(FRC2, true);
+    timer_set_run(FRC2, true);
+}
+
+void user_init(void)
+{
+    uart_set_baud(0, 115200);
+    printf("SDK version:%s\n", sdk_system_get_sdk_version());
+
+    struct sdk_station_config config = {
+        .ssid = WIFI_SSID,
+        .password = WIFI_PASS,
+    };
+
+    /* required to call wifi_set_opmode before station_set_config */
+    sdk_wifi_set_opmode(STATION_MODE);
+    sdk_wifi_station_set_config(&config);
+
+	// Mess with FRC2 to test if it interferes with FreeRTOS
+	Frc2Config();
+
+    xTaskCreate(SntpTsk, (signed char *)"SNTP", 1024, NULL, 1, NULL);
+}
+