Update configuration APIs

e220/config.go

@@ -0,0 +1,108 @@
+package e220
+
+import "fmt"
+
+type Config struct {
+	ModuleAddr         uint16
+	UartSerialPortRate uint8
+	AirDataRate        uint8
+	SubPacket          uint8
+	RssiAmbient        uint8
+	TransmitPower      uint8
+	Channel            uint8
+	RssiByte           uint8
+	TransmitMethod     uint8
+	WorCycleSetting    uint8
+	EncryptionKey      uint16
+	Version            uint8
+}
+
+func (c *Config) paramsToBytes(
+	bytes *[]byte,
+) error {
+	// byte [8] is read only
+	if len(*bytes) < E220RegisterLength-1 {
+		return fmt.Errorf("bytes must be greater than or equal to %d: got=%d", E220RegisterLength-1, (*bytes))
+	}
+	(*bytes)[0] = byte((c.ModuleAddr & 0xFF00) >> 8)
+	(*bytes)[1] = byte((c.ModuleAddr & 0x00FF) >> 0)
+	(*bytes)[2] = byte(((c.UartSerialPortRate & 0x07) << 5) | (c.AirDataRate & 0x1F))
+	reserved := byte(0b000)
+	(*bytes)[3] = byte(((c.SubPacket & 0x03) << 6) | ((c.RssiAmbient & 0x01) << 5) | ((reserved & 0x07) << 2) | (c.TransmitPower & 0x03))
+	(*bytes)[4] = byte(c.Channel)
+	reserved = byte(0b000)
+	(*bytes)[5] = byte(((c.RssiByte & 0x01) << 7) | ((c.TransmitMethod & 0x01) << 6) | ((reserved & 0x07) << 3) | (c.WorCycleSetting & 0x07))
+	(*bytes)[6] = byte((c.EncryptionKey & 0xFF00) >> 8)
+	(*bytes)[7] = byte((c.EncryptionKey & 0x00FF) >> 0)
+
+	return nil
+}
+
+func (c *Config) bytesToParams(bytes []byte) error {
+	if len(bytes) < E220RegisterLength {
+		return fmt.Errorf("bytes must be greater than or equal to %d: got=%d", E220RegisterLength, (bytes))
+	}
+	c.ModuleAddr = uint16((uint16(bytes[0]) << 8) | (uint16(bytes[1]) << 0))
+	c.UartSerialPortRate = uint8((bytes[2] & 0xE0) >> 5)
+	c.AirDataRate = uint8((bytes[2] & 0x1F) >> 0)
+	c.SubPacket = uint8((bytes[3] & 0xC0) >> 6)
+	c.RssiAmbient = uint8((bytes[3] & 0x20) >> 5)
+	c.TransmitPower = uint8((bytes[3] & 0x03) >> 0)
+	c.Channel = bytes[4]
+	c.RssiByte = uint8((bytes[5] & 0x80) >> 7)
+	c.TransmitMethod = uint8((bytes[5] & 0x40) >> 6)
+	c.WorCycleSetting = uint8((bytes[5] & 0x07) >> 0)
+	c.EncryptionKey = uint16((uint16(bytes[6]) << 8) | (uint16(bytes[7]) << 0))
+	c.Version = bytes[8]
+
+	return nil
+}
+
+func (c *Config) String() string {
+	moduleAddr := fmt.Sprintf("ModuleAddr0x%04X", c.ModuleAddr)
+	channel := fmt.Sprintf("Channel%02d", c.Channel)
+	uartSerialPortRate, ok := uartSerialPortRateStrings[c.UartSerialPortRate]
+	if !ok {
+		uartSerialPortRate = "UartSerialPortRate: invalid parameter"
+	}
+	airDataRate, ok := airDataRateStrings[c.AirDataRate]
+	if !ok {
+		airDataRate = "AirDataRate: invalid parameter"
+	}
+	subPacket, ok := subPacketStrings[c.SubPacket]
+	if !ok {
+		subPacket = "SubPacket: invalid parameter"
+	}
+	rssiAmbient, ok := rssiAmbientString[c.RssiAmbient]
+	if !ok {
+		rssiAmbient = "RSSIAmbient: invalid parameter"
+	}
+	transmitPower, ok := transmitPowerString[c.TransmitPower]
+	if !ok {
+		transmitPower = "TransmitPower: invalid parameter"
+	}
+	rssiByte, ok := rssiByteString[c.RssiByte]
+	if !ok {
+		rssiByte = "RSSIByte: invalid parameter"
+	}
+	transmitMethod, ok := transmitMethodString[c.TransmitMethod]
+	if !ok {
+		transmitMethod = "TransmitMethod: invalid parameter"
+	}
+	worCycleSetting, ok := worCycleSettingString[c.WorCycleSetting]
+	if !ok {
+		worCycleSetting = "WorCycleSetting: invalid parameter"
+	}
+	encryptionKey := fmt.Sprintf("EncryptionKey0x%04X", c.ModuleAddr)
+	if !ok {
+		worCycleSetting = "WorCycleSetting: invalid parameter"
+	}
+	version := fmt.Sprintf("Version0x%02X", c.Version)
+
+	return fmt.Sprintf(
+		"%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s",
+		moduleAddr, channel, uartSerialPortRate, airDataRate,
+		subPacket, rssiAmbient, transmitPower, rssiByte,
+		transmitMethod, worCycleSetting, encryptionKey, version,
+	)
+}

e220/e220.go

@@ -136,7 +136,7 @@ func (d *Device) ReadRegister(startAddr uint8, length uint8) ([]byte, error) {
 		return nil, fmt.Errorf("unexpected response: %X", response)
 	}
 
-	return response, nil
+	return response[3:], nil
 }
 
 // WriteRegister writes the register value from startAddr to the value of params
@@ -204,46 +204,38 @@ func (d *Device) writeRegister(cmd, startAddr, length uint8, params []byte) ([]b
 		}
 		runtime.Gosched()
 	}
+	// Wait for a while because the next register access
+	// cannot be received immediately after register access
+	time.Sleep(50 * time.Millisecond)
+
 	return d.payload[:readIndex], nil
 }
 
 // WriteConfig writes configuration values to E220
-func (d *Device) WriteConfig(
-	moduleAddr uint16,
-	uartSerialPortRate uint8,
-	airDataRate uint8,
-	subPacket uint8,
-	rssiAmbient uint8,
-	transmitPower uint8,
-	channel uint8,
-	rssiByte uint8,
-	transmitMethod uint8,
-	worCycleSetting uint8,
-	encryptionKey uint16,
-) error {
-	if uartSerialPortRate > UartSerialPortRate115200Bps {
-		return fmt.Errorf("uartSerialPortRate must be less than or equal to %d, got=%d", UartSerialPortRate115200Bps, uartSerialPortRate)
+func (d *Device) WriteConfig(cfg Config) error {
+	if cfg.UartSerialPortRate > UartSerialPortRate115200Bps {
+		return fmt.Errorf("uartSerialPortRate must be less than or equal to %d, got=%d", UartSerialPortRate115200Bps, cfg.UartSerialPortRate)
 	}
-	if airDataRate > AirDataRate2148Bps {
-		return fmt.Errorf("airDataRate must be less than or equal to %d, got=%d", AirDataRate2148Bps, airDataRate)
+	if cfg.AirDataRate > AirDataRate2148Bps {
+		return fmt.Errorf("airDataRate must be less than or equal to %d, got=%d", AirDataRate2148Bps, cfg.AirDataRate)
 	}
-	if subPacket > SubPacket32Bytes {
-		return fmt.Errorf("subPacket must be less than or equal to %d, got=%d", SubPacket32Bytes, subPacket)
+	if cfg.SubPacket > SubPacket32Bytes {
+		return fmt.Errorf("subPacket must be less than or equal to %d, got=%d", SubPacket32Bytes, cfg.SubPacket)
 	}
-	if rssiAmbient > RSSIAmbientEnable {
-		return fmt.Errorf("rssiAmbient must be less than or equal to %d, got=%d", RSSIAmbientEnable, rssiAmbient)
+	if cfg.RssiAmbient > RSSIAmbientEnable {
+		return fmt.Errorf("rssiAmbient must be less than or equal to %d, got=%d", RSSIAmbientEnable, cfg.RssiAmbient)
 	}
-	if transmitPower > TransmitPower0Dbm {
-		return fmt.Errorf("transmitPower must be less than or equal to %d, got=%d", TransmitPower0Dbm, transmitPower)
+	if cfg.TransmitPower > TransmitPower0Dbm {
+		return fmt.Errorf("transmitPower must be less than or equal to %d, got=%d", TransmitPower0Dbm, cfg.TransmitPower)
 	}
-	if rssiByte > RSSIByteEnable {
-		return fmt.Errorf("rssiByte must be less than or equal to %d, got=%d", RSSIByteEnable, rssiByte)
+	if cfg.RssiByte > RSSIByteEnable {
+		return fmt.Errorf("rssiByte must be less than or equal to %d, got=%d", RSSIByteEnable, cfg.RssiByte)
 	}
-	if transmitMethod > TransmitMethodFixed {
-		return fmt.Errorf("transmitMethod must be less than or equal to %d, got=%d", TransmitMethodFixed, transmitMethod)
+	if cfg.TransmitMethod > TransmitMethodFixed {
+		return fmt.Errorf("transmitMethod must be less than or equal to %d, got=%d", TransmitMethodFixed, cfg.TransmitMethod)
 	}
-	if worCycleSetting > WorCycleSetting4000ms {
-		return fmt.Errorf("worCycleSetting must be less than or equal to %d, got=%d", WorCycleSetting4000ms, transmitMethod)
+	if cfg.WorCycleSetting > WorCycleSetting4000ms {
+		return fmt.Errorf("worCycleSetting must be less than or equal to %d, got=%d", WorCycleSetting4000ms, cfg.TransmitMethod)
 	}
 
 	var bwTbl = map[uint8]uint16{
@@ -267,71 +259,42 @@ func (d *Device) WriteConfig(
 		AirDataRate2148Bps:  500,
 	}
 
-	switch bwTbl[airDataRate] {
+	switch bwTbl[cfg.AirDataRate] {
 	case 125:
-		if channel > 37 {
-			return fmt.Errorf("if band width is %dKHz, channel must be less than or equal to %d, got=%d", 125, 37, channel)
+		if cfg.Channel > 37 {
+			return fmt.Errorf("if band width is %dKHz, cfg.Channel must be less than or equal to %d, got=%d", 125, 37, cfg.Channel)
 		}
 	case 250:
-		if channel > 36 {
-			return fmt.Errorf("if band width is %dKHz, channel must be less than or equal to %d, got=%d", 250, 36, channel)
+		if cfg.Channel > 36 {
+			return fmt.Errorf("if band width is %dKHz, cfg.Channel must be less than or equal to %d, got=%d", 250, 36, cfg.Channel)
 		}
 	case 500:
-		if channel > 30 {
-			return fmt.Errorf("if band width is %dKHz, channel must be less than or equal to %d, got=%d", 500, 30, channel)
+		if cfg.Channel > 30 {
+			return fmt.Errorf("if band width is %dKHz, cfg.Channel must be less than or equal to %d, got=%d", 500, 30, cfg.Channel)
 		}
 	default:
-		return fmt.Errorf("invalid band width value: %d", bwTbl[airDataRate])
-	}
-
-	paramsToBytes(
-		&d.parameters,
-		moduleAddr,
-		uartSerialPortRate,
-		airDataRate,
-		subPacket,
-		rssiAmbient,
-		transmitPower,
-		channel,
-		rssiByte,
-		transmitMethod,
-		worCycleSetting,
-		encryptionKey,
-	)
+		return fmt.Errorf("invalid band width value: %d", bwTbl[cfg.AirDataRate])
+	}
 
-	return d.WriteRegister(0x00, d.parameters)
-}
+	cfg.paramsToBytes(&d.parameters)
 
-func paramsToBytes(
-	bytes *[]byte,
-	moduleAddr uint16,
-	uartSerialPortRate uint8,
-	airDataRate uint8,
-	subPacket uint8,
-	rssiAmbient uint8,
-	transmitPower uint8,
-	channel uint8,
-	rssiByte uint8,
-	transmitMethod uint8,
-	worCycleSetting uint8,
-	encryptionKey uint16,
-) {
-	(*bytes)[0] = byte((moduleAddr & 0xFF00) >> 8)
-	(*bytes)[1] = byte((moduleAddr & 0x00FF) >> 0)
-	(*bytes)[2] = byte(((uartSerialPortRate & 0x07) << 5) | (airDataRate & 0x1F))
-	reserved := byte(0b000)
-	(*bytes)[3] = byte(((subPacket & 0x03) << 6) | ((rssiAmbient & 0x01) << 5) | ((reserved & 0x07) << 2) | (transmitPower & 0x03))
-	(*bytes)[4] = byte(channel)
-	reserved = byte(0b000)
-	(*bytes)[5] = byte(((rssiByte & 0x01) << 7) | ((transmitMethod & 0x01) << 6) | ((reserved & 0x07) << 3) | (worCycleSetting & 0x07))
-	(*bytes)[6] = byte((encryptionKey & 0xFF00) >> 8)
-	(*bytes)[7] = byte((encryptionKey & 0x00FF) >> 0)
+	return d.WriteRegister(0x00, d.parameters)
 }
 
 // ReadConfig reads configuration values from E220
-func (d *Device) ReadConfig() ([]byte, error) {
+func (d *Device) ReadConfig() (*Config, error) {
 	// "+1" is read only register (addr = 0x08)
-	return d.ReadRegister(0x00, writingRegisterSize+1)
+	registerBytes, err := d.ReadRegister(0x00, writingRegisterSize+1)
+	if err != nil {
+		return nil, err
+	}
+	config := Config{}
+	err = config.bytesToParams(registerBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	return &config, nil
 }
 
 // IsReady returns whether the device is ready for new commands.