func setSpeed(folder string, speed int16) {
regulationMode := utilities.ReadStringValue(folder, regulationModeFD)
switch regulationMode {
case "on":
utilities.WriteIntValue(folder, speedSetterFD, int64(speed))
case "off":
if speed > 100 || speed < -100 {
log.Fatal("The speed must be in range [-100, 100]")
}
utilities.WriteIntValue(folder, powerSetterFD, int64(speed))
}
}
func findSensor(port InPort, t Type) string {
sensors, _ := ioutil.ReadDir(baseSensorPath)
for _, item := range sensors {
if strings.HasPrefix(item.Name(), "sensor") {
sensorPath := fmt.Sprintf("%s/%s", baseSensorPath, item.Name())
portr := utilities.ReadStringValue(sensorPath, "address")
if InPort(portr) == port {
typer := utilities.ReadStringValue(sensorPath, "driver_name")
if Type(typer) == t {
return item.Name()
}
}
}
}
log.Fatalf("Could not find %v sensor on port %v\n", t, port)
return ""
}
// Runs the motor at the given port.
// The meaning of `speed` parameter depends on whether the regulation mode is turned on or off.
//
// When the regulation mode is off (by default) `speed` ranges from -100 to 100 and
// it's absolute value indicates the percent of motor's power usage. It can be roughly interpreted as
// a motor speed, but deepending on the environment, the actual speed of the motor
// may be lower than the target speed.
//
// When the regulation mode is on (has to be enabled by EnableRegulationMode function) the motor
// driver attempts to keep the motor speed at the `speed` value you've specified
// which ranges from about -1000 to 1000. The actual range depends on the type of the motor - see ev3dev docs.
//
// Negative values indicate reverse motion regardless of the regulation mode.
func Run(port OutPort, speed int16) {
folder := findFolder(port)
regulationMode := utilities.ReadStringValue(folder, regulationModeFD)
switch regulationMode {
case "on":
utilities.WriteIntValue(folder, speedSetterFD, int64(speed))
utilities.WriteStringValue(folder, runFD, "run-forever")
case "off":
if speed > 100 || speed < -100 {
log.Fatal("The speed must be in range [-100, 100]")
}
utilities.WriteIntValue(folder, powerSetterFD, int64(speed))
utilities.WriteStringValue(folder, runFD, "run-forever")
}
}
func findFolder(port OutPort) string {
if _, err := os.Stat(rootMotorPath); os.IsNotExist(err) {
log.Fatal("There are no motors connected")
}
rootMotorFolder, _ := os.Open(rootMotorPath)
motorFolders, _ := rootMotorFolder.Readdir(-1)
if len(motorFolders) == 0 {
log.Fatal("There are no motors connected")
}
for _, folderInfo := range motorFolders {
folder := folderInfo.Name()
motorPort := utilities.ReadStringValue(path.Join(rootMotorPath, folder), portFD)
if motorPort == "out"+string(port) {
return path.Join(rootMotorPath, folder)
}
}
log.Fatal("No motor is connected to port ", port)
return ""
}
// Read motor state
func ReadState(port OutPort) string {
return utilities.ReadStringValue(findFolder(port), stateFD)
}