This is a very simple guide, reviewing the steps required to get Blinky working on an Mbed OS platform.

Mbed OS Blinky

This example shows the use of a DigitalOut object to represent an LED and use of the nonblocking Thread::wait() call. Using nonblocking calls is good practice because Mbed OS can schedule and run other threads while the first thread is waiting.

Building this example

Building with Arm Mbed CLI

To use Mbed CLI to build this example, follow the instructions in the documentation. The instructions here relate to using the Arm Online Compiler.

To use the Online Compiler, import this code into the Online Compiler, and select your platform from the top right. Compile the code using the compile button, load it onto your board and press the reset button on the board. The code will run on the board, and you will see the LED blink.

You can find more instructions for using the Mbed Online Compiler in the documentation.


5 weeks ago

File content as of revision 94:ef34de021f40:

/* mbed Microcontroller Library
 * Copyright (c) 2018 ARM Limited
 * SPDX-License-Identifier: Apache-2.0


#include "mbed.h"

 *  System Reporting library. Provides runtime information on device:
 *      - CPU sleep, idle, and wake times
 *      - Heap and stack usage
 *      - Thread information
 *      - Static system information
class SystemReport {
    mbed_stats_heap_t   heap_stats;
    mbed_stats_cpu_t    cpu_stats;
    mbed_stats_sys_t    sys_stats;

    mbed_stats_thread_t *thread_stats;
    uint8_t   thread_count;
    uint8_t   max_thread_count;
    uint32_t  sample_time_ms;

     *  SystemReport - Sample rate in ms is required to handle the CPU percent awake logic
    SystemReport(uint32_t sample_rate) : max_thread_count(8), sample_time_ms(sample_rate)
        thread_stats = new mbed_stats_thread_t[max_thread_count];

        // Collect the static system information

        printf("=============================== SYSTEM INFO  ================================\r\n");
        printf("Mbed OS Version: %ld \r\n", sys_stats.os_version);
        printf("CPU ID: 0x%lx \r\n", sys_stats.cpu_id);
        printf("Compiler ID: %d \r\n", sys_stats.compiler_id);
        printf("Compiler Version: %ld \r\n", sys_stats.compiler_version);

        for (int i = 0; i < MBED_MAX_MEM_REGIONS; i++) {
            if (sys_stats.ram_size[i] != 0) {
                printf("RAM%d: Start 0x%lx Size: 0x%lx \r\n", i, sys_stats.ram_start[i], sys_stats.ram_size[i]);
        for (int i = 0; i < MBED_MAX_MEM_REGIONS; i++) {
            if (sys_stats.rom_size[i] != 0) {
                printf("ROM%d: Start 0x%lx Size: 0x%lx \r\n", i, sys_stats.rom_start[i], sys_stats.rom_size[i]);


     *  Report on each Mbed OS Platform stats API
    void report_state(void)

        // Clear next line to separate subsequent report logs

     *  Report CPU idle and awake time in terms of percentage
    void report_cpu_stats(void)
        static uint64_t prev_idle_time = 0;

        printf("================= CPU STATS =================\r\n");

        // Collect and print cpu stats

        uint64_t diff = (cpu_stats.idle_time - prev_idle_time);
        uint8_t idle = (diff * 100) / (sample_time_ms * 1000);  // usec;
        uint8_t usage = 100 - ((diff * 100) / (sample_time_ms * 1000));  // usec;;
        prev_idle_time = cpu_stats.idle_time;

        printf("Idle: %d%% Usage: %d%% \r\n", idle, usage);

     *  Report current heap stats. Current heap refers to the current amount of
     *  allocated heap. Max heap refers to the highest amount of heap allocated
     *  since reset.
    void report_heap_stats(void)
        printf("================ HEAP STATS =================\r\n");

        // Collect and print heap stats

        printf("Current heap: %lu\r\n", heap_stats.current_size);
        printf("Max heap size: %lu\r\n", heap_stats.max_size);

     *  Report active thread stats
    void report_thread_stats(void)
        printf("================ THREAD STATS ===============\r\n");

        // Collect and print running thread stats
        int count = mbed_stats_thread_get_each(thread_stats, max_thread_count);

        for (int i = 0; i < count; i++) {
            printf("ID: 0x%lx \r\n",        thread_stats[i].id);
            printf("Name: %s \r\n",         thread_stats[i].name);
            printf("State: %ld \r\n",       thread_stats[i].state);
            printf("Priority: %ld \r\n",    thread_stats[i].priority);
            printf("Stack Size: %ld \r\n",  thread_stats[i].stack_size);
            printf("Stack Space: %ld \r\n", thread_stats[i].stack_space);

#endif // STATS_REPORT_H