B4J Library jSerial Enhanced Library

Hello everyone.
This is my own personal all‑in‑one jSerial Enhanced library. I use this library for all my personal and client work when it comes to serial communications. No iRandomAccessFile is needed to receive new data.

I’ve added plenty of extra features for myself, but obviously you don’t need to use them. The basic send‑and‑receive functionality works perfectly once the COM port has been initialized and is open.

This is the latest version of jSerial available on GitHub, so I wrapped it for my own use (and for my clients), and now I’m sharing it with the B4X community.

I sometimes use this library to monitor industrial hardware communications, and also when testing Arduino and ESP32 code, as well as for other serial based communication solutions.

CLICK HERE to use Erels original JSerial library.

This library is fully asynchronous and non‑blocking. It operates on its own dedicated thread, and disconnecting the serial adapter while the port is open and the application is active does not result in a crash, ANR, or any other instability.

This library can be used to monitor applications, control or query microcontrollers (such as Arduino, ESP, etc devices), or simply send and receive any data required when interacting with RS232‑based hardware.

B4J library tab:

CH340

Standard serial adapters also work

SS_jSerialEnhanced

Author: Peter Simpson
Version: 1.0

• jSerialEnhanced
  Enhanced Serial library for B4J using the jSerialComm backend.
  • Events:
    • BreakInterrupt()
    • Closed()
    • DataSent (Data() As Byte)
    • Error (Message As String)
    • FramingError (Message As String)
    • LineReceived (Line As String)
    • NewData (Data() As Byte)
    • Opened()
    • OverrunError (Message As String)
    • ParityError (Message As String)
    • PortAdded (PortName As String)
    • PortDisconnected()
    • PortReconfigured()
    • PortRemoved (PortName As String)
    • Reconnected()
    • StatsUpdated (Stats As Map)
  • Fields:
    • AggregationIdleWindowMs As Int
      Idle window (ms) after the last received byte before emitting one
      aggregated _NewData event. Increase to capture microbursts; decrease for lower latency.
      Default: 20
    • AggregationMaxTotalMs As Int
      Safety cap (ms) for total aggregation time to avoid waiting indefinitely
      while coalescing a burst. Only raise this for very slow, long bursts.
      Default: 500
    • AggregationPollMs As Int
      Poll interval (ms) used while aggregating incoming bytes.
      Lower values reduce aggregation latency; higher values reduce CPU wakeups.
      Default: 5
    • EnableLoopbackSimulation As Boolean
      Enables software loopback simulation.
      EnableLoopbackSimulation returns written data as incoming data.
    • EnableLowLatency As Boolean
      Requests low‑latency read behaviour.
      EnableLowLatency reduces driver timeouts where supported.
    • SetDebugLogging As Boolean
      Enables diagnostic logging.
      SetDebugLogging writes internal debug messages to the log.
  • Functions:
    • BytesToHex (data As Byte(), offset As Int, length As Int) As String
      Converts a byte array to a space‑separated hexadecimal string.
      data is the byte array to convert.
      Return a formatted hexadecimal string, or an empty string if the array is null or empty.
    • ClearInternalBuffer
      Clears the internalBuffer contents.
    • Close
      Closes the port and performs full cleanup.
      Triggers PortDisconnected and Closed events.
    • DecodeBase64ToString (base64 As String) As String
    • EncodeBase64FromString (text As String) As String
      Encodes a standard Java String into a Base64 text representation.
      text is the plain text String to encode. Must not be null.
      Return a Base64‑encoded String representing the original text.
    • GetDeviceType (portName As String) As String
      Returns a short chipset identifier based on the port's VID.
    • GetOpenPortName As String
      Returns the system name of the currently open port.
      Returns an empty string if no port is open.
    • GetPortInfo (portName As String) As Map
      Returns a Map containing detailed hardware and USB information for the port.
    • GetStats As Map
      Returns a Map containing current statistics.
    • HexToBytes (hex As String) As Byte()
      Converts a hexadecimal string to a byte array.
      Non‑hex characters are ignored. The string must contain an even number of hex digits.
      hex is the hexadecimal string to convert.
      Return a byte array containing the converted values.
    • Initialize (EventName As String)
      Initialises the object and sets the event prefix.
      EventName: the event name prefix for callbacks.
    • IsCTS As Boolean
      Returns true if the CTS line is asserted.
    • IsDCD As Boolean
      Returns true if the DCD line is asserted.
    • IsDSR As Boolean
      Returns true if the DSR line is asserted.
    • IsPortBusy (portName As String) As Boolean
      Returns true if the specified port appears to be busy.
      Returns false if it can be opened or is already open by this instance.
    • IsRI As Boolean
      Returns true if the RI line is asserted.
    • ListPorts As List
      Returns a B4X List of available system COM port names.
      The list is sorted in a human-friendly order.
    • Open (portName As String, baud As Int, dataBits As Int, stopBits As Int, parity As Int) As Boolean
      Opens the specified serial port with the given parameters.
      Returns true on success, false on failure.
    • PurgeAll
      Clears internal buffers and attempts hardware purge if supported.
    • PurgeRX
      Clears internal RX buffer and attempts hardware RX purge.
    • PurgeTX
      Clears TX queue and attempts hardware TX purge.
    • ReadAvailable As Byte()
      Returns a snapshot of currently available bytes in internalBuffer without consuming them.
    • ReadExact (count As Int, timeoutMs As Long) As Byte()
      Read exactly 'count' bytes or null on timeout.
      timeoutMs = 0 means non-blocking (single check).
    • ReadUntil (terminator As Byte, timeoutMs As Long) As Byte()
      Read until the terminator byte is seen or timeout expires.
      Returns the bytes up to and including the terminator, or null on timeout.
      timeoutMs = 0 means non-blocking (single check).
    • ReadWithTimeout (minBytes As Int, timeoutMs As Int) As Byte()
      Reads until at least minBytes are available or timeout expires.
      Returns whatever bytes are available.
    • SendBreak (durationMs As Int)
      Sends a break signal for the specified duration in milliseconds.
    • SetAccumulationDelay (ms As Int)
      Sets the accumulation delay used to reduce fragmentation.
      ms: delay in milliseconds.
    • SetFlowControl (mode As Int)
      Sets the hardware flow control mode.
      mode: one of the SerialPort.FLOW_CONTROL_* constants.
    • SetParameters (baud As Int, dataBits As Int, stopBits As Int, parity As Int)
      Applies new serial parameters to the open port and raises the
      PortReconfigured event if the port is active.
      baud specifies the baud rate.
      dataBits specifies the number of data bits.
      stopBits specifies the number of stop bits.
      parity specifies the parity mode (0–4).
    • Write (data As Byte())
      Queues a byte array for transmission.
      If loopback is enabled, data is injected locally.
  • Properties:
    • EnableAutoReconnect As Boolean
      Returns the current AutoReconnect setting.
    • SetDTR As Boolean
      Returns the last known DTR state.

Enjoy...