--- title: GRIDBluFly Setup Guide for Serial Bluetooth Communication description: The GRIDBluFly is a Bluetooth serial adapter that wirelessly replaces an RS232 cable. A serial device connects to the GRIDBluFly through its DB9 port. A... --- [Skip to content](https://support.gridconnect.com/grid-connect/gridblufly-setup-guide-for-serial-bluetooth-communication#main-content) [Submit a ticket](https://support.gridconnect.com/grid-connect/kb-tickets/new?hsLang=en) ![Grid Connect](https://support.gridconnect.com/hubfs/GridConnect_FullColorLogo-2024.svg) Open main navigation Close main navigation - [Submit a ticket](https://support.gridconnect.com/grid-connect/kb-tickets/new) How can we help you? - There are no suggestions because the search field is empty. 1. [Grid Connect](https://support.gridconnect.com/grid-connect?hsLang=en) 2. [Grid Connect Products](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en) 3. [GRIDBluFly](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#gridblufly) # GRIDBluFly Setup Guide for Serial Bluetooth Communication The GRIDBluFly is a Bluetooth serial adapter that wirelessly replaces an RS232 cable. A serial device connects to the GRIDBluFly through its DB9 port. A PC or laptop connects wirelessly via Bluetooth, creating a virtual COM port for two-way serial communication. This guide covers the full setup process from factory reset to verified communication. --- ## Before you start Set all 4 DIP switches on the GRIDBluFly to **OFF**. These are located on the side of the device. ![GRIDBluFly DIP switches all in OFF position](https://support.gridconnect.com/hubfs/kb-migration/gridconnect/50889720696467_50889720696467.jpeg) All switches in OFF position (pushed to the right). ON is to the left, OFF is to the right, as indicated by the arrows printed on the device. --- ## 1. Factory reset (if needed) If the device was previously configured or is not responding as expected, perform a factory reset before continuing. 1. Set Switch 1 (Factory Defaults) to **ON** 2. Power on the GRIDBluFly 3. Leave Switch 1 ON during configuration. Turn it OFF when done. --- ## 2. Verify the baud rate The GRIDBluFly must be configured to match the baud rate of the serial device it is connected to. Use a terminal emulator (Tera Term recommended) connected to the GRIDBluFly's serial port to check and set this. ### Open the serial connection Connect to the GRIDBluFly's serial COM port with these settings: ![Tera Term serial port setup showing 8N1 no flow control](https://support.gridconnect.com/hubfs/kb-migration/gridconnect/50889110307731_50889110307731.png) Make sure Data, Parity, Stop bits and Flow control match exactly. Set Speed to match your device's baud rate. ### Enter command mode Type exactly, without pressing Enter: `$$$` The device responds with `CMD` and the Status LED blinks rapidly. ### Check current settings `D` Look for the `Baudrt` field. If it does not match your serial device's baud rate, change it now. ![Tera Term showing output of D command with current GRIDBluFly settings including baud rate](https://support.gridconnect.com/hubfs/kb-migration/gridconnect/50888830883731_50888830883731.png) Output of the D command showing current device settings ### Change baud rate (if needed) Use the `SU` command followed by the value from the table below. Only the first 2 characters of the baud rate are used. **Note:** Rates above 9600 use abbreviated notation. 115200 is **SU,115K**, not SU,115200. Reboot to apply: `R,1` After reboot, reconnect with the new baud rate and verify with `$$$` and `D` again. **Once the baud rate is confirmed, set Switch 1 (Factory Defaults) back to OFF.** --- ## 3. Pair the PC via Bluetooth 1. Go to **Settings \> Devices \> Bluetooth & other devices** 2. Click **Add Bluetooth or other device**, then select **Bluetooth** 3. Select **GRIDBluFly-XXXX** from the list (XXXX = last 4 digits of MAC address). Do not select the **-BLE** variant. 4. If asked, enter PIN `1234` and click **Connect**. Some versions of Windows complete pairing without asking for a PIN. 5. Open **Device Manager \> Ports (COM & LPT)**. Two new COM ports appear labeled *Standard Serial over Bluetooth link*. 6. Start with the highest numbered COM port. If it does not connect, try the next lower one. ![Tera Term serial port selection showing COM5 and COM6 as Standard Serial over Bluetooth link](https://support.gridconnect.com/hubfs/kb-migration/gridconnect/50888847698195_50888847698195.png) Tera Term showing the two Bluetooth COM ports. Start with the highest numbered one. 7. The Bluetooth manager may show the device as **Not connected** or **Disconnected** even after successful pairing. This is normal. The device only shows as connected when a terminal emulator has the COM port open and data is actively flowing. --- ## 4. Verify the connection Open a terminal emulator on the PC using the Bluetooth COM port. Use the same baud rate and serial settings as section 2. 1. Exit command mode if still active: type `---` and press Enter. Expected response: `END` 2. Type from the PC. Text should appear on the serial side. 3. Type from the serial side. Text should appear on the PC. 4. Both directions working = tunnel is operational. Command mode can also be entered from the Bluetooth side using `$$$`. This only works within 60 seconds of power-up. --- ## Status LED reference --- ## Quick command reference --- ## Important notes - If you are migrating from a FireFly device and experiencing pairing issues, see: [Migrating from FireFly to GRIDBluFly? Try these settings](https://gridconnect.zendesk.com/hc/en-us/articles/50890848991635) - The GRIDBluFly supports **RS232 only**. It does not support RS485. - All devices on the serial network must use the **same baud rate**. - Default pairing PIN is **1234**. This can be changed with the `SP` command. - Switch 1 must be set back to **OFF** after configuration is complete. - If using Linux, use `cat` or similar raw tools. minicom and screen may drop bytes due to RS232 signal handling. - [Grid Connect Products](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#main-content) - [Device Installer](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#device-installer) - [Com Port](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#com-port) - [GRIDBluFly](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#gridblufly) - [NET485-01](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#net485-01) - [Serial to Ethernet](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#serial-to-ethernet) - [Serial over Bluetooth](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#serial-over-bluetooth) - [xPort](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#xport) - [CAN](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#can) - [NET485-MB](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#net485-mb) - [WI232+](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#wi232) - [NET232+](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#net232) - [Testing and Evaluation](https://support.gridconnect.com/grid-connect/grid-connect-products?hsLang=en#testing-and-evaluation) - [Distributed Vendors](https://support.gridconnect.com/grid-connect/distributed-vendors?hsLang=en#main-content) - [AKCP](https://support.gridconnect.com/grid-connect/distributed-vendors?hsLang=en#akcp) - [ATC](https://support.gridconnect.com/grid-connect/distributed-vendors?hsLang=en#atc) - [Chiyu](https://support.gridconnect.com/grid-connect/distributed-vendors?hsLang=en#chiyu) - [Deutschmann Automation](https://support.gridconnect.com/grid-connect/distributed-vendors?hsLang=en#deutschmann-automation) - [Equustek](https://support.gridconnect.com/grid-connect/distributed-vendors?hsLang=en#equustek) - [PEAK System](https://support.gridconnect.com/grid-connect/distributed-vendors?hsLang=en#peak-system) - [Profichip](https://support.gridconnect.com/grid-connect/distributed-vendors?hsLang=en#profichip) - [Zcomax](https://support.gridconnect.com/grid-connect/distributed-vendors?hsLang=en#zcomax) - [Procentec](https://support.gridconnect.com/grid-connect/distributed-vendors?hsLang=en#procentec) - [Contemporary Controls](https://support.gridconnect.com/grid-connect/distributed-vendors?hsLang=en#contemporary-controls) - [General](https://support.gridconnect.com/grid-connect/general?hsLang=en#main-content) - [FAQ](https://support.gridconnect.com/grid-connect/general?hsLang=en#faq) - [RS232](https://support.gridconnect.com/grid-connect/general?hsLang=en#rs232) - [Support](https://support.gridconnect.com/grid-connect/support?hsLang=en#main-content) - [How To guides](https://support.gridconnect.com/grid-connect/support?hsLang=en#how-to-guides) - [FAQs](https://support.gridconnect.com/grid-connect/support?hsLang=en#faqs) - [Troubleshooting](https://support.gridconnect.com/grid-connect/support?hsLang=en#troubleshooting) [![Grid Connect](https://support.gridconnect.com/hubfs/GridConnect_FullColorLogo-2024.svg "Grid Connect")](https://www.gridconnect.com/) Copyright © 2026, Grid Connect