first push of

pi/roverd/serial.go

@@ -0,0 +1,86 @@
+package roverd
+
+import (
+	"encoding/base64"
+	"fmt"
+	"io"
+	"log"
+	"sync"
+
+	"github.com/tarm/serial"
+)
+
+type SerialAdapter struct {
+	port    io.ReadWriteCloser
+	encoder *base64.Encoding
+	mu      sync.Mutex
+	log     *log.Logger
+}
+
+func OpenSerial(cfg SerialConfig) (*serial.Port, error) {
+	return serial.OpenPort(&serial.Config{
+		Name:        cfg.Device,
+		Baud:        cfg.Baud,
+		ReadTimeout: sensorReadTimeout,
+	})
+}
+
+func NewSerialAdapter(port io.ReadWriteCloser, logger *log.Logger) *SerialAdapter {
+	return &SerialAdapter{
+		port:    port,
+		encoder: base64.StdEncoding,
+		log:     logger,
+	}
+}
+
+func (s *SerialAdapter) write(buf []byte) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	n, err := s.port.Write(buf)
+	if err != nil {
+		return err
+	}
+	if n != len(buf) {
+		return fmt.Errorf("short write %d/%d", n, len(buf))
+	}
+	return nil
+}
+
+func (s *SerialAdapter) DriveDirect(left, right int) error {
+	payload := []byte{
+		145,
+		byte((right >> 8) & 0xFF),
+		byte(right & 0xFF),
+		byte((left >> 8) & 0xFF),
+		byte(left & 0xFF),
+	}
+	return s.write(payload)
+}
+
+func (s *SerialAdapter) MotorPWM(main, side, vacuum int) error {
+	payload := []byte{
+		144,
+		byte(main & 0xFF),
+		byte(side & 0xFF),
+		byte(vacuum & 0xFF),
+	}
+	return s.write(payload)
+}
+
+func (s *SerialAdapter) StartSensorStream(group byte) error {
+	payload := []byte{148, 1, group}
+	return s.write(payload)
+}
+
+func (s *SerialAdapter) PauseSensorStream(pause bool) error {
+	state := byte(1)
+	if pause {
+		state = 0
+	}
+	return s.write([]byte{150, state})
+}
+
+func (s *SerialAdapter) SendRaw(raw []byte) error {
+	return s.write(raw)
+}