WiFi serial adapter / wireless serial bridge
These names emphasize replacing the physical host-to-serial cable with a wireless network link while the equipment continues using RS232.
// RS232 over WiFi · local TCP serial connectivity
Connect RS232 equipment over WiFi.
Keep legacy hardware useful.
A WiFi serial adapter, wireless serial bridge, or serial device server can let compatible RS232 equipment communicate with modern computers, phones, tablets, and embedded applications without replacing the equipment or depending on a cloud service. GhostBridge GB-01 provides a direct local TCP-to-standard-3-wire-RS232 connection.
// The connection
RS232 on one side. TCP over WiFi on the other.
The bridge does not need to understand the application protocol. It transports serial bytes between the connected RS232 device and a TCP client on the local WiFi network.
RS232 deviceTX · RX · GND
Serial bridgeRS232 ↔ TCP
Local WiFiNo internet required
Client softwareComputer · phone · tablet · embedded
// Common terminology
WiFi serial adapter, serial device server, and RS232-to-TCP/IP bridge.
Those phrases are often used for closely related products. The details vary by device, but the shared job is moving serial data between an RS232 interface and a network-capable host.
Serial device server
This broader industrial term usually describes hardware that exposes one or more serial ports through a network connection such as TCP.
RS232 to TCP/IP
This wording emphasizes the transport conversion: serial bytes on the equipment side are carried through a TCP/IP network connection on the host side.
Transparent TCP-to-serial bridge
“Transparent” means the bridge forwards the byte stream without needing to understand the device's higher-level application protocol.
For a deeper explanation of the network side, read TCP to RS232: what a serial device server does.
// How it works
Transparent serial transport.
1. Serial data enters the bridge
A compatible device sends ordinary asynchronous RS232 data through TX, RX, and ground. The bridge's RS232 transceiver converts those signals to logic-level UART data for the controller.
2. The data becomes a TCP stream
The bridge forwards those bytes through a local TCP connection instead of interpreting what the bytes mean. Binary and text-based application protocols can both be transported.
3. A modern client receives it
A TCP-capable application can connect directly. Older Windows software that insists on a COM port may use a suitable TCP-to-virtual-COM layer.
4. Replies travel back the same way
Bytes sent by the host application travel through WiFi and TCP, through the bridge, and back out the RS232 transmitter to the attached equipment.
// Common use categories
The market is much broader than automotive.
Compatibility depends on the actual electrical and serial interface, not the industry the device came from. A compatible RS232 port can appear on equipment in many fields.
Industrial & automation
Controllers, meters, setup/configuration ports, and factory equipment that use standard 3-wire RS232 communication.
Test & measurement
Benchtop instruments, laboratory devices, data loggers, and measurement equipment with compatible RS232 interfaces.
Embedded systems
Custom controllers, development systems, and installed devices that still expose RS232 for configuration or data exchange.
Legacy equipment
Older hardware that remains useful but expects a physical serial connection to software running on a modern host.
Automotive & diagnostics
ECUs, diagnostic devices, and controllers with compatible RS232 ports. GhostTune with MicroSquirt / MS2/Extra 3.4.4 is the currently published verified Crux Resolve automotive configuration.
OEM & custom deployments
Products and installations that need a compact local serial-to-WiFi path, application-specific defaults, or firmware behavior tailored to a deployment. Explore OEM and custom-firmware options.
// Serial connectivity guides & use cases
Go deeper from the part of the connection you are solving.
These guides cover the decisions and failure points that sit around a WiFi-to-RS232 bridge: choosing the transport, identifying the electrical interface, matching cabling, working with legacy software, and evaluating specific workflows.
WiFi RS232 vs USB serial
Choose the simpler transport for the actual workflow instead of assuming wireless is always better.
Is that DB9 really RS232?
Separate connector shape from electrical signaling, pinout, and protocol before connecting equipment.
CNC / DNC program transfer
Understand XON/XOFF vs RTS/CTS, virtual COM paths, cabling, and drip-feed considerations before evaluating a CNC control.
Legacy equipment to a modern computer
Compare USB serial, TCP serial servers, WiFi bridges, and virtual COM software for older equipment.
TCP to RS232 device servers
See how transparent byte transport works and what a serial device server does—and does not—change.
3-wire RS232: TX, RX, GND
Learn when three-wire communication is enough and when hardware control signals make it insufficient.
DTE, DCE & null-modem wiring
Work out why two valid RS232 endpoints may still need TX/RX crossover rather than a straight-through cable.
Still not sure your device fits?
Send the model, interface details, serial settings, and host software you know before ordering.
// Compatibility
Check the interface, not just the connector.
A strong GB-01 candidate
- Uses true RS232 electrical signaling.
- Communicates with TX, RX, and GND.
- Does not require RTS/CTS or other hardware modem-control lines.
- Uses serial settings supported by the installed GhostBridge firmware.
- Can use a TCP client or a suitable TCP-to-virtual-COM solution.
- Has a compatible DTE/DCE pinout or can use the appropriate cable/adapter.
Current GhostBridge GB-01 interface
- DB9 male connector.
- Pin 2: RX into GhostBridge.
- Pin 3: TX out of GhostBridge.
- Pin 5: signal ground.
- Current GB-01 hardware does not provide RTS/CTS, DTR/DSR, DCD, or RI.
- USB-C provides bridge power.
DB9 does not automatically mean RS232. Some equipment uses a DB9 connector for TTL serial, RS485, CAN, proprietary signaling, or a nonstandard pinout. Confirm the device documentation before connecting it.
// Choose your next step
Start from the problem you are trying to solve.
Different visitors arrive with different serial problems. These paths keep you from digging through ECU-specific material when your goal is industrial, embedded, test, or legacy equipment connectivity.
I need a bridge for standard 3-wire RS232
Review the current GB-01 specifications, connection behavior, price, and ordering details.
I have a specific device and I am not sure it will work
Send the manufacturer, model, interface, settings, and host software you know. Crux Resolve can review obvious fit issues before you order.
My old software only wants a COM port
Learn how TCP-to-serial bridges fit with older desktop applications and where a virtual COM-port layer may be needed.
I need custom firmware or repeat deployments
For OEM, product integration, application-specific defaults, or multiple identical installations, start with the project requirements rather than the retail checkout.
// Why local WiFi
No router. No cloud. No subscription.
Direct local access
GhostBridge creates its own WiFi access point, so the host can connect directly even where there is no existing network infrastructure.
Legacy hardware stays in service
Instead of redesigning or replacing a functioning serial device, a bridge can move the connection layer to WiFi while leaving the original equipment and application protocol intact.
Protocol-independent transport
The bridge moves bytes rather than trying to understand the higher-level message format. Compatibility still depends on serial settings, pinout, timing, and host software.
Modern client choices
TCP-capable software can connect directly from a computer, phone, tablet, or embedded client. Legacy COM-port applications may be usable through a suitable virtual-COM layer.
// RS232 over WiFi FAQ
Common questions.
Is RS232 over WiFi still real RS232?
The equipment side remains electrically RS232. The bridge converts between the serial interface and a network transport so the host no longer needs to be physically tethered to the serial port.
Does the bridge need to know my device protocol?
Not for transparent transport. The bridge moves the byte stream. The host application and attached device remain responsible for understanding the application protocol.
Can binary data be transported?
Yes. A transparent TCP-to-serial bridge can transport arbitrary byte values; it is not limited to readable text commands.
Can existing serial software still be used?
Software with native TCP support can connect directly. Software that only opens a local COM port may require a compatible TCP-to-virtual-COM utility.
When is a null-modem adapter needed?
It depends on the DTE/DCE arrangement and pinout of the connected equipment. Two similarly oriented endpoints often require TX/RX crossover.
Does GhostBridge support hardware flow control?
The current GB-01 production hardware is a 3-wire interface and does not route RTS/CTS or other modem-control signals to the DB9 connector.
// GhostBridge GB-01
A compact local WiFi-to-RS232 bridge.
GhostBridge is available now for compatible standard 3-wire RS232 applications. If your device is not already listed as verified, Crux Resolve can review its interface requirements before you order.