Examples: Rename main.c files to more descriptive file names

examples/simple/simple.c

@@ -0,0 +1,44 @@
+/* Very basic example that just demonstrates we can run at all!
+ */
+#include "espressif/esp_common.h"
+#include "espressif/sdk_private.h"
+#include "FreeRTOS.h"
+#include "task.h"
+#include "queue.h"
+
+void task1(void *pvParameters)
+{
+    xQueueHandle *queue = (xQueueHandle *)pvParameters;
+    printf("Hello from task1!\r\n");
+    uint32_t count = 0;
+    while(1) {
+        vTaskDelay(100);
+        xQueueSend(*queue, &count, 0);
+        count++;
+    }
+}
+
+void task2(void *pvParameters)
+{
+    printf("Hello from task 2!\r\n");
+    xQueueHandle *queue = (xQueueHandle *)pvParameters;
+    while(1) {
+        uint32_t count;
+        if(xQueueReceive(*queue, &count, 1000)) {
+            printf("Got %d\n", count);
+        } else {
+            printf("No msg :(\n");
+        }
+    }
+}
+
+static xQueueHandle mainqueue;
+
+void user_init(void)
+{
+    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    printf("SDK version:%s\n", sdk_system_get_sdk_version());
+    mainqueue = xQueueCreate(10, sizeof(uint32_t));
+    xTaskCreate(task1, (signed char *)"tsk1", 256, &mainqueue, 2, NULL);
+    xTaskCreate(task2, (signed char *)"tsk2", 256, &mainqueue, 2, NULL);
+}