Watson Industries, Inc.
SBM Rev A 08/08/2016
3
Product Description
The Serial to Bluetooth Module (SBM) acts as a wireless serial connection utilizing serial port
protocol (SPP). The Bluetooth network can be paired to any Android device or Bluetooth-enabled
PC via a virtual COM port. It’s often as simple as plug, power, and connect.
Installation
If using the SBM with a DMS, SHR, or GCM product, simply plug the module into the serial port
of the Watson sensor. If using with a VRS product, install the VRS to Bluetooth Adapter between
the serial port and the SBM.
The default baud rate of all compatible Watson sensor units is 9600. Therefore, pin 4 of the SBM
should initially be set (positioned further from the connector).
Environment
The SBM is not resistant to the elements. Therefore, avoid mounting sites where water, snow, or
particulate matter will work their way into the plastic housing.
Power
The sensor unit powers the SBM with +5VDC through pin 9 of the serial connection.
Pin-Out
Connecting to an Android Device
1. Make sure the SBM baud rate is properly set (see below).
2. Power the sensor unit.
3. Plug the SBM into the sensor unit’s 9-pin serial port (using a VRS to Bluetooth Adapter if
connecting to a VRS sensor).
4. Wait for the green light on the SBM to begin blinking. This indicates that a Bluetooth
signal has been generated and is awaiting a device to pair with.
5. Open a terminal program (We recommend Blue Term, available at the Google Play store –
also linked from our website).
6. Connect to “Watson SBM”. To do this using Blue Term, press the square button to bring
up the menu. Then press “Connect Device”.
7. Enter the Device’s pairing code (default is “3035”)
SBM Connector Pin Out
PIN
Function
1
No Connection
2
RXD
3
TXD
4
No Connection
5
GND
6
No Connection
7
RTS
8
CTS
9
4-12 VDC