How to setup the BlueSnap AAA for use with the Fowler digital caliper

The article demonstrates how to set up the BlueSnap AAA Bluetooth 2.1 to RS-232 adapter for use with the Fowler digital caliper.


The BlueSnap must have the DTR modification option and firmware version 4.77.


Set the BlueSnap’s jumpers for DTE. See page 3 in the BlueSnap manual.

Establish a Connection via the Terminal

1. Connect the BlueSnap to a Mac or Windows PC via the RS-232 to USB configuration cable.

2. Launch a terminal application, and set the serial communication settings to match the BlueSnap defaults (see table below).

Baud rate115200
Data bits8
Stop bits1

3. Power on the BlueSnap by holding down the red button for approximately three seconds. You should see the LEDs come on.

4. Enter the BlueSnap’s command mode by typing $$$.

Configure Serial Communication Settings

Issue the commands to set the BlueSnap serial communication settings to match the Fowler digital caliper’s settings.


Verify Settings

The R,1 command doesn’t restart the BlueSnap AAA. Instead, it simply powers it off, so you will need to power it back on after sending the restart command. This is by design. However, before powering your BlueSnap back on, you’ll need to configure the terminal to match the BlueSnap’s new serial communication settings (see the table below).

Baud rate4800
Data bits7
Stop bits2

Send the d command to verify that the settings match the information in the table below. Although, if the settings aren’t correct, you won’t be able to establish a connection to the BlueSnap after changing the terminal’s settings.


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