Getting started with connectBlue Serial Port Modules

ConnectBlue Serial Port Modules are easy to use. This post provides you with some hints and tips you cannot find in the manuals or documentations. As an example the standard USB adapter "cB-ACC-34" and a "cB-OBS411i-04" Bluetooth module are used.

Following modules will also work:

• cB-OBS410 (Classic Bluetooth)
• cB-OBS411 (Classic Bluetooth)
• cB-OBS414 (Classic Bluetooth)
• cB-OBS421 (Classic Bluetooth)
• cB-OBS421 (Dual Mode Bluetooth smart ready)
• cB-OBS433 (Classic Bluetooth)
• cB-OLS426 (Bluetooth Smart)
• cB-OWS451 (Dual Band WIFI, 802.11a/b/g/n)
• cB-OZS311 (802.15.4/Zigbee)

Factory settings for UART Interface
Baud Rate: 57600 bps
Data Bits: 8
Parity: none
Stop Bits: 1
Flow Control: RTS/CTS

Escape Sequence (to switch from Data Mode into AT Configuration Mode)
1st break of 1000ms followed by three "/" (slashes without the quotes) followed by a 2nd break of 1000ms. This is handled by the SPA Toolbox software automatically.

Basic information about evaluation adapter cB-ACC-34
The cB-ACC-34 is an USB adapter for the connectBlue UART modules. It utilizes a FTDI chip and provides a "virtual COM port" in Windows and is used together with the free "connectBlue Serial Port Adapter Toolbox" Windows configuration software.

cB-ACC-34 with mounted OBS411

How to mount the connectBlue modules in the right direction on the ACC-34 adapter?

Make sure the antenna or the U.Fl. antenna connector (if you have chosen the "x" version) points to the right if the USB connector of the adapter points away form you, as shown in the left picture.

The power +5V power is provided through the USB connection. Don't worry if you initially mounted the module to other way possible on the adapter. It has an internal protection and should still work properly once you mount it correctly.

If you got problems to connect to the module after you have changed some interface settings, push and hold the "restore switch" for 5 seconds during power up. This will temporarily set the serial interface to the factory default settings.

Installation and use of the connectBlue Serial Port Adapter (SPA) Toolbox

With the SPA Toolbox, connectBlue provides you a comprehensive and easy to use Windows Software (XP, Windows 7, Windows 8) to configure the serial modules. You can download the current version at http://support.connectblue.com.

After installing the software you simply choose your module type, the COM port which has been assigned to the USB adapter, click on "Connect" and push the button "AT Mode" to get into configuration mode.( Note: It will take about 2 seconds to enter AT mode). The status LED will switch from "green, purple or blue" to "orange"). To read the module configuration, please push the "Read All" button. Don't mind if you recognize some "Errors" in the Status window. This is normal as not all parameter needs to be set.

For more information please review the "SPA Toolbox Getting Started" document. 

How to reset the module with factory defaults?

Occasionally you may face problems with the connection including a lost connection to the module, after you have done several changes in the configuration. A reset to factory defaults will help you to start your configuration again:

1. Start the SPA Toolbox and select your type of module
2. Press and hold the "Restore Switch" while plugging the adapter with module into your USB port for 5 seconds (configures the UART settings temporarily to standard)
3. Now connect with the default interface setting to the COM port which is assigned to the adapter
4. Switch to AT Mode
5. Place cursor into the Terminal/Status window and type "AT&F" (without the quotes) and hit "Return".
6. Make sure that the checkbox "Reset Module Going To Data Mode" is checked and push the "Data Mode" button.

The module configuration is now set to factory defaults.

Note: For new developments, please make sure the modules have the latest firmware version. The current firmware version is indicated in the terminal window after you have connected to the module with the SPA Toolbox. We recommend to update the F/W before you start your configuration work. Find the latest versions at http://www.connectblue.com/support/product-support/. Updating the module firmware WILL NOT overwrite the configuration settings!

Improve support and test different configurations

The SPA Toolbox allows you to export and import configuration files (TXT Format). You can either use this to save a working configuration before testing a new configuration or, if you need support, send the TXT file to our support team to solve a problem. 

Save a configuration:

While being in "AT Mode", click on "Read All" to load the configuration of the modules into the SPA Toolbox.

You can now save your configuration in a TXT file.

Download a configuration:

To download a configuration into your module you click on Files --> Download Configuration and select the configuration TXT file.

Make sure that you click "Write All" afterwards and check "Reset Going To Data Mode" before switching from AT Mode to Data Mode.

Compatibility of connectBlue modules over generations and technologies

connectBlue modules are designed to work over generation and technologies. This means that it is possible to switch between different modules without the need make changes to your design. This is also guaranteed if an old module generation becomes EOL and the successors needs to be used in your application. Even if you like to switch from let say an OBS411 Bluetooth module to a OWS451 Dual-Band WIFI module it is possible to do that without making changes to your hardware.

But to achieve that that level of flexibility, there are some hints which are quite important.

Choose the right connector for your design

Option 1: Use the SAMTEC 2-row connector for 100% flexibility

The "Samtec Option" gives you the most flexibility in your design. All connectBlue modules are equipt with this Board to Board connector option marked as J2 and J3 in the data sheet. The SAMTEC connector (cB-ACC-33) will soldered on your PCB and you screw the module on top of it (like with the ACC-34 USB adapter). This connector is in use for more than 10 years now and will also be available in the future. 

Choose this option if you want to have the flexibility to use all different connectBlue modules or if you want to integrate wireless function as an option for your customers. Note that you would need to manually screw the module on the connector which is a drawback when it comes to numbers.

Option 2: Use the solder edges for full automatic production

The solder edges (J6 in the data sheet)are also available by standard with all connectBlue modules and the pin out is standardized between all modules. As connectBlue has two different module formats you would have either choose the narrow or the wide layout. This is important because you can not make a layout for both formats as you have to avoid connections beneath the modules (risk of shortcuts).

Option 3: Flexible mounting with 6-pol JST connector

The JST connector (J8 in the data sheet) is also a standardized connectBlue interface and available as an order option for most of the modules. This is a good option if you want to place the module somewhere else in your housing to optimize the antenna performance or if you want to equip you products optional with wireless technology. Due to the limited number of pins, this option only provides you the UART and Power connection. Don't choose this connector option if you like to connect DTR, DSR, H/W Reset, LEDs and the I/O ports of the modules.

Design hints for circuits, placement and layout

1. Minimum connection should be: VCC, GND, RxD, TxD, RTS and CTS
2. If possible connect DSR, DTR and RESET
3. Avoid to combine the use of different H/W Interfaces (Either use J6 or J2/J3 or J8)
4. Make sure that you have a stable and low resistive power supply with a linear regulator
5. Avoid peaks which exceed the maximum operating voltage
6. Make sure that there is no ground plane beneath the antenna area of the module. (see recommendations in the data sheets.
7. Place the module at the edge of your PCB if possible. 

We hope this was helpful getting you started with the connectBlue Serial Port Modules. Let us know if we can assist you further in your evaluation.

If you got more common questions or own hints please comment on this post. If you need assistance please do not hesitate to send an email to sales@score-electronics.com.