feat: 添加测试demo

test/goserial/main.go

@@ -0,0 +1,95 @@
+package main
+
+import (
+	"errors"
+	"log"
+	"time"
+
+	"go.bug.st/serial"
+)
+
+const (
+	portName    = "/dev/ttyS9"
+	baudRate    = 115200
+	timeout     = 5 * time.Second
+	reopenDelay = 500 * time.Millisecond
+)
+
+func main() {
+	log.Println("goserial test tool started")
+	log.Printf("configuration: port=%s baud=%d", portName, baudRate)
+
+	for {
+		if err := runTest(); err != nil {
+			log.Printf("test run failed, will reopen port after delay: %v", err)
+			time.Sleep(reopenDelay)
+			continue
+		}
+	}
+}
+
+func runTest() error {
+	log.Println("opening serial port")
+
+	// 打开端口
+	port, err := serial.Open(portName, &serial.Mode{
+		BaudRate: baudRate,
+	})
+	if err != nil {
+		log.Printf("failed to open serial port %s: %v", portName, err)
+		return err
+	}
+	defer func() {
+		log.Println("closing serial port")
+		if err := port.Close(); err != nil {
+			log.Printf("failed to close serial port: %v", err)
+		}
+	}()
+
+	// 设置读取超时
+	if err := port.SetReadTimeout(timeout); err != nil {
+		log.Printf("failed to set read timeout: %v", err)
+		return err
+	}
+
+	log.Printf("read timeout set: %v", timeout)
+	log.Println("start reading from serial port (synchronous mode)")
+
+	// 创建缓冲区用于读取数据
+	buffer := make([]byte, 24)
+
+	// 同步读取循环
+	for {
+		n, err := port.Read(buffer)
+		if err != nil {
+			// 检查是否是超时错误
+			if err.Error() == "i/o timeout" {
+				log.Println("serial port read timeout occurred, exiting read loop")
+				// 超时后退出循环，重新打开端口
+				break
+			}
+
+			// 使用类型断言检查是否是PortError
+			var portErr *serial.PortError
+			if errors.As(err, &portErr) {
+				// 检查错误代码是否为PortClosed
+				if portErr.Code() == serial.PortClosed {
+					log.Println("port closed, exiting read loop")
+					break
+				}
+			}
+
+			// 其他错误
+			log.Printf("error reading from serial port: %v", err)
+			return err
+		}
+
+		if n > 0 {
+			log.Printf("data received: bytes=%d data=%v", n, buffer[:n])
+		}
+	}
+
+	// 正常退出读取循环
+	log.Println("read loop exited normally")
+	return nil
+}