LED Blink (NO-OS)

Overview

This example demonstrates LED blinking functionality using GPIO to better understand GPIO usage.

Supported Development Boards

This example can run on the following development boards:

• eh-lb520

• eh-lb523

• eh-lb525

• eh-lb561

• eh-lb563

• eh-ss6500

Note: Generally, examples run on the chip’s HCPU. If you want to run the example on LCPU, you can use “eh-lb563_lcpu”.

Example Directory Structure

The Blink project contains 1 .c file (main.c). The tree structure below shows other files in the project directory.

|--Readme.md
|--no-os
|--rtt
    |--src
    |    |--main.c
    |    |--Sconscript
    |--project  
         |--Kconfig
         |--Kconfig.proj
         |--proj.conf
         |--rtconfig.py
         |--SConscript
         |--SConstruct

Example Usage

Hardware Requirements

To run this example, you need to have a development board that supports this example.

Pin Configuration

Note: The table below shows the pin configurations for LED control on each development board.

	pin assign
eh-lb523	PA25
eh-lb520	PA25
eh-lb525	PA25
eh-lb561	PA41
eh-lb563	PA41
eh-ss6500	PA41

Compilation and Flashing

Follow these steps to complete compilation and flashing:

menuconfig --board=eh-lb523
scons --board=eh-lb523 -j8
 .\build_eh-lb523\uart_download.bat

Example Output Results

The following results show the log after the example runs on the development board. If you cannot see these logs, it means the example did not run successfully as expected and troubleshooting is needed.

Start example blink
Turning the LED OFF
Turning the LED ON

Troubleshooting

If the expected logs do not appear, troubleshooting can be performed from the following aspects:

• Whether hardware connections are normal

• Whether pin configuration is correct

Example Extension

To control more LEDs, the following example shows how to extend the example by adding a second LED on development board eh-lb523:

1. Modify the kconfig file “\siflisdk\customer\boards\Kconfig.v2” to add LED2 option: BSP_USING_LED2;

menuconfig BSP_USING_LED2
   bool "Use LED2"
   default n
   if BSP_USING_LED2  
       config BSP_LED2_PIN
           int "LED2 pin number"
           default 99
       config BSP_LED2_ACTIVE_HIGH
           bool "Level is high if LED is on"
           default n
   endif 

2. Modify the development board configuration file “\siflisdk\customer\boards\eh-lb523\hcpu\board.conf” to enable LED2 and configure the corresponding pin and active level;

CONFIG_BSP_USING_LED2=y
CONFIG_BSP_LED2_PIN=26
CONFIG_BSP_LED2_ACTIVE_HIGH=y

The above configuration is the default configuration for eh-lb523, i.e., LED2 is configured to pin 26 by default; if you want to modify it to another pin, you can run menuconfig –board eh-lb523 to modify it;

3. Modify the code main.c to control BSP_LED2_PINs to implement LED blinking;

int main(void)
{
  /*recode led state*/

  /* Output a message on console using printf function */
  rt_kprintf("Start example blink\n");

  /*Init pin state */
  rt_pin_mode(BSP_LED1_PIN, PIN_MODE_OUTPUT);
    rt_pin_mode(BSP_LED2_PIN, PIN_MODE_OUTPUT);
  bool state = RT_FALSE;

  /* Infinite loop, len flash inter 1s */
  while (1)
  {
    rt_kprintf("Turning the LED %s", state == RT_TRUE ? "ON" : "OFF");
#ifndef BSP_LED1_ACTIVE_HIGH
    rt_pin_write(BSP_LED1_PIN, !state);
    rt_pin_write(BSP_LED2_PIN, !state);
#else
    rt_pin_write(BSP_LED1_PIN, state);
  	  rt_pin_write(BSP_LED2_PIN, !state);
#endif
    /*toggle the LED statu*/
    state = !state;

    rt_thread_mdelay(1000);
  }
  return 0;
}