28BYJ4+ULN2003

28BYJ48是一种步进电机，而ULN2003是一种常用的步进电机驱动芯片。28BYJ48步进电机需要使用驱动芯片ULN2003来控制。以下是28BYJ48步进电机与ULN2003驱动芯片的连接方式：
- IN1连接到ULN2003的1号引脚
- IN2连接到ULN2003的2号引脚
- IN3连接到ULN2003的3号引脚
- IN4连接到ULN2003的4号引脚
- VCC连接到ULN2003的9号引脚
- GND连接到ULN2003的10号引脚

以下是一个基于Arduino的28BYJ48步进电机控制程序示例，需要使用ULN2003驱动芯片：

// 定义步进电机的引脚
#define IN1 8
#define IN2 9
#define IN3 10
#define IN4 11

// 步进电机每一步的状态
int stepState[8][4] = {
  {HIGH, LOW, LOW, LOW},
  {HIGH, HIGH, LOW, LOW},
  {LOW, HIGH, LOW, LOW},
  {LOW, HIGH, HIGH, LOW},
  {LOW, LOW, HIGH, LOW},
  {LOW, LOW, HIGH, HIGH},
  {LOW, LOW, LOW, HIGH},
  {HIGH, LOW, LOW, HIGH}
};

// 步进电机当前步数
int currentStep = 0;

void setup() {
  // 初始化步进电机引脚
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
}

void loop() {
  // 控制步进电机顺时针旋转
  for (int i = 0; i < 512; i++) {
    digitalWrite(IN1, stepState[currentStep % 8][0]);
    digitalWrite(IN2, stepState[currentStep % 8][1]);
    digitalWrite(IN3, stepState[currentStep % 8][2]);
    digitalWrite(IN4, stepState[currentStep % 8][3]);
    delayMicroseconds(1000);
    currentStep++;
  }
  // 控制步进电机逆时针旋转
  for (int i = 0; i < 512; i++) {
    digitalWrite(IN1, stepState[(currentStep + 7) % 8][0]);
    digitalWrite(IN2, stepState[(currentStep + 7) % 8][1]);
    digitalWrite(IN3, stepState[(currentStep + 7) % 8][2]);
    digitalWrite(IN4, stepState[(currentStep + 7) % 8][3]);
    delayMicroseconds(1000);
    currentStep--;
  }
}