Classic implementation method of Hongmeng system controlling LED

Today I would like to talk with you , How to use the domestic Hongmeng operating system to control led Hardware .

First of all ： Introduction to domestic Hongmeng system

      Hongmeng system is a new distributed operating system based on micro kernel , Provide a new user experience for all devices and scenarios , And more fluent in scene experience , Support seamless collaboration of devices . It's a whole scene , Future oriented operating systems , It can be installed on mobile phones 、 watch 、 Unmanned aerial vehicles and other equipment .

       The development of Hongmeng is divided into two directions , South and North . Northbound mainly refers to application development , Application development has special IDE Tools ; The mainstream development languages used are ：java ,js etc. . South direction mainly refers to equipment development , It's based on LiteOS Developed by Microkernel , Lightweight 、 Low power consumption , It can be applied to intelligent devices , And can use soft bus connection .

second ： Domestic Hongmeng hardware analysis

        Since this is to talk about the control of Hongmeng system lamp , First, let's get to know the corresponding GPIO. Used in this experiment Hi3861 The chip contains GPIO modular . The module can mainly realize the digital input or output function on the chip pin . We know that because machines can only recognize 0 and 1 Digital quantity of , So what we usually say GPIO The input / output state of the port refers to 0 or 1 state , That's what they say 0 For low level ,1 For high level .

        How do you feel after reading the schematic diagram above , One word absolutely , Is it very clear

. The analysis is as follows ：

       J3 It's two rows of needles , By default, it is connected by jumping cap , It is in the on state , Can be regarded as directly connected .LEDI Is the core board programmable LED The lamp , One end of it passes through a row of needles J3 And the master chip GPIO09 Pin connection , The other end passes through a resistor R6 Connect to 3V3 Power Supply .

because LED1 And the master chip GPI009 Pin to pin , So the master chip GPIO09 Pin output different levels can be controlled LED1 The state of . According to the analysis of schematic diagram , Master chip GPI009 Pin status and LED1 The corresponding relationship of the state is low-level lighting , High level off .

Third ： Code implementation method

         Hongmeng IOT The hardware provides an application programming interface for controlling peripherals , Popular is also legendary API,GPIO Relevant API Function to realize control , The master code is as follows ：

#include <stdio.h>​#include <unistd.h>​#include "cmsis_os2.h"#include "ohos_init.h"#include "wifiiot_gpio.h"#include "wifiiot_gpio_ex.h"​#define LED_TASK_STACK_SIZE 1024#define LED_TASK_PRIO 25​static void* GpioTask(const char* arg){
       (void)arg;​    GpioInit();  IoSetFunc(WIFI_IOT_IO_NAME_GPIO_9, WIFI_IOT_IO_FUNC_GPIO_9_GPIO);    GpioSetDir(WIFI_IOT_IO_NAME_GPIO_9, WIFI_IOT_GPIO_DIR_OUT);​    while (1) {
               printf(" LED_SPARK! \n");            GpioSetOutputVal(WIFI_IOT_IO_NAME_GPIO_9, WIFI_IOT_GPIO_VALUE0);            osDelay(50);            GpioSetOutputVal(WIFI_IOT_IO_NAME_GPIO_9, WIFI_IOT_GPIO_VALUE1);            osDelay(50);        }    return NULL;}​static void GpioExampleEntry(void){
       osThreadAttr_t attr;​    attr.name = "GpioTask";    attr.attr_bits = 0U;    attr.cb_mem = NULL;    attr.cb_size = 0U;    attr.stack_mem = NULL;    attr.stack_size = LED_TASK_STACK_SIZE;    attr.priority = LED_TASK_PRIO;​    if (osThreadNew((osThreadFunc_t)GpioTask, NULL, &attr) == NULL) {
           printf("[GpioExample] Falied to create GpioTask!\n");    }}​SYS_RUN(GpioExampleEntry);

        Write here , I thought it was over , In fact, the long march has just begun

. To make the code work , You also need to configure and compile the system, as shown in the video .​

​ Fourth ： Effect demonstration

Hongmeng system