81 lines
1.3 KiB
Go
81 lines
1.3 KiB
Go
package uart
|
|
|
|
import (
|
|
"bytes"
|
|
"io"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/tarm/serial"
|
|
)
|
|
|
|
const (
|
|
BUFFERSIZE = 4096
|
|
READTIMEOUT = 50 * time.Millisecond
|
|
IDLE = 200 * time.Millisecond
|
|
)
|
|
|
|
type UART struct {
|
|
port *serial.Port
|
|
}
|
|
|
|
func New(device string, baud int) (*UART, error) {
|
|
c := &serial.Config{
|
|
Name: device,
|
|
Baud: baud,
|
|
ReadTimeout: READTIMEOUT,
|
|
}
|
|
|
|
p, err := serial.OpenPort(c)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &UART{port: p}, nil
|
|
}
|
|
|
|
func (u *UART) Write(cmd string) error {
|
|
_, err := u.port.Write([]byte(strings.TrimSpace(cmd) + "\r"))
|
|
return err
|
|
}
|
|
|
|
func (u *UART) ReadResponse() (string, error) {
|
|
buf := make([]byte, BUFFERSIZE)
|
|
var out bytes.Buffer
|
|
|
|
received := false
|
|
lastData := time.Now()
|
|
for {
|
|
n, err := u.port.Read(buf)
|
|
|
|
if err != nil && err != io.EOF && !errorsIsTimeout(err) {
|
|
return "", err
|
|
}
|
|
|
|
if n > 0 {
|
|
received = true
|
|
lastData = time.Now()
|
|
out.Write(buf[:n])
|
|
}
|
|
|
|
if received && time.Since(lastData) >= IDLE {
|
|
return strings.TrimSpace(out.String()), nil
|
|
}
|
|
}
|
|
}
|
|
|
|
func errorsIsTimeout(err error) bool {
|
|
return strings.Contains(strings.ToLower(err.Error()), "timeout")
|
|
}
|
|
|
|
func (u *UART) Exec(cmd string) (string, error) {
|
|
if err := u.Write(cmd); err != nil {
|
|
return "", err
|
|
}
|
|
return u.ReadResponse()
|
|
}
|
|
|
|
func (u *UART) Close() error {
|
|
return u.port.Close()
|
|
}
|