Document number: 10551448
Release: May 21, 2015 15:13
Document version: 14
Bluetooth Serial Port Adapter™ firmware, cB-2254, with Wireless Multidrop™ and Extended Data Mode support (up to 7 simultaneous Bluetooth connections).
The firmware is valid for the following Serial Port Adapter™ models:
Products with Bluetooth low energy support
This firmware is valid for the module versions listed above only. Firmware for other OBS421 module versions (modules without Bluetooth low energy support) is available in document cB-OBS421 Firmware
If you experience problems with your Serial Port Adapter™ please fill out an anomaly report and email it to email@example.com.
5.3.2 [00:28:06,Apr 29 2015]
Known Limitations and Notes
Remote name does not work for peripherals with random address
The work-around is to use GATT AT-commands for this instead, see example below.
Read remote device name:
Re-bond with resolvable address does not work
A work-around is to first delete the bonded device and then do an inquiry to get the current address
Windows 7 Authentication Work-Around
The way that Microsoft Windows 7 handles Bluetooth connections, may in some use-cases, cause issues during the authentication phase between the device and the Bluetooth module. To solve these potential issues, connectBlue has implemented a Windows 7 authentication work-around in the Bluetooth module.
To enable the work-around, set the Windows 7 Work-Around feature bit using the feature bit mask register command.
The command needs to be called only once and the module must be restarted for the command to take affect.
Automatic Packet Control
An automatic packet control algorithm was implemented to improve link robustness for long range or if there are obstacles. It is enabled only for link policy 0 (see AT*AMLP). The algorithm decreases the packet size if the link is poor, to improve robustness. It prioritizes link robustness at the cost of keeping the best performance for as long as possible. If you find it too defensive and prefer to keep the bigger size packets for better throughput the automatic packet control algorithm can be disabled by setting link policy (0,1) or any other link policy than the default one (0).
- Use link policy 0,0 for BR packets with the connectBlue packet control algorithm.
- Use link policy 0,3 for EDR packets with the connectBlue packet control algorithm (faster for short range).
- Use link policy 13,0 (or 0,1) for BR packets only without the connectBlue packet control algorithm.
- Use link policy 2,0 for EDR packets without the connectBlue packet control algorithm.
Exit Sniff on Data Activity
When the module is configured with a link policy for sniff mode with exit sniff mode on data activity (Link policy (4,1), (5,1), (6,1), (7,1), (8,1)), there is a risk of data loss.
Removing of stored link keys
When upgrading from previous versions the stored link keys will be removed because of a new link key format.
Advertising and scan response data
For the v5.1.3 release the connectBlue Serial Service service UUID was added to the scan response data. It was added to the scan response data instead of the advertising data for backwards compatibility with earlier firmware versions. However, when a central device is using passive scan instead of active scan the central device will only see the advertising data and not the scan response data.
For example Apple recommends filtering on UUIDs when doing a scan in iOS apps and may use passive scan when the app is not active. This may require that the UUID is part of the advertising data instead of the scan response data.
Use the commands below to set the connectBlue Serial Service service UUID in the advertising data and set the device name in the scan response data:
|AT*AGAD=020a04110701d7e9014ff344e7838fe226b9e15624,1||Set advertising data to:|
Tx power: 4dBm [020a04]
128-bit Service UUIDs, complete list: connectBlue Serial Service UUID[110701d7e9014ff344e7838fe226b9e15624]
|AT*AGSD=07094f4253343231,1||Set scan response data to:|
Complete Local Name: OBS421 [07094f4253343231] where
07 is the length of the data
09 is the AD type complete local name
4f4253343231 is the name data
to set a different name change the length and name data fields
|cB-2254-11(fw_obs421_rd_v5.3.1).bin||5.3.1 [23:47:57,Mar 31 2015]|
|cB-2254-09(fw_obs421_rd_v5.2.1).bin||5.2.1 [11:50:43,Jun 12 2014]|
|cB-2254-08(fw_obs421_rd_v5.2.0).bin||5.2.0 [00:55:10,Feb 27 2014]|
|cB-2254-07(fw_obs421_rd_v5.1.4).bin||5.1.4 [20:18:39,Dec 12 2013]|
|cB-2254-06(fw_obs421_rd_v5.1.3).bin||5.1.3 [16:31:02,Oct 24 2013]|
|cB-2254-04(fw_obs421_rd_v5.1.1).bin||5.1.1 [20:00:29,Jun 19 2013]|
|cB-2254-03(fw_obs421_rd_v5.1.0).bin||5.1.0 [17:01:45,Jun 11 2013]|
|cB-2254-02(fw_obs421_rd_v5.0.2).bin||5.0.2 [15:49:16,Feb 1 2013]|