BLED 112 - update BGScript based firmware with SDK v1.1.1

Question

I purchased a BLED 112 dongle from BlueGiga (http://www.bluegiga.com/BLED112_Bluetooth_smart_dongle). I purchased the dongle since I was trying to do a simple POC with an iPhone. I did not want to get into breakout boards or the dev kit just yet.

I am trying to get the heart rate monitor samples working and I am not sure how to load the firmware on the device. I am using the latest version of the SDK (v1.1.1) which states to use the BLE Update tool, not the TI Flash Tool.

However it looks like you need the CC Debugger with the BLE Update Tool to update the SOC. I looked at the CC Debugger and it does not appear to be designed to be used with BLED 112 USB dongle. It appears you need a breakout board to expose the pins to be able to hook the CC Debugger to a BLE 112 module, not a BLED 112.

Lastly, I am not sure if DFU will work without bricking the dongle.

Any advice on how to properly use and program the BLED 112?

Thanks, G

From the SDK docs:

TI Flash tool should NOT be used with the Bluegiga Bluetooth Smart SDK v.1.1 or newer, but BLE Update tool should be used instead. The BLE112 and BLE113 and BLED112 devices contain a security key, which is needed for the firmware to operate and if the device is programmed with TI flash tool, this security key will be erased.

Answer 1

It is possible to update the firmware on the BLED112 via the USB connection, and without requiring a breakout box or a CC Debugger. However, it is fairly easy to accidentally 'brick' your device in so doing. The problem is that the firmware itself needs to provide the interface to enable DFU mode; if you do an update with your own firmware, and your firmware doesn't provide this capability, you're stuck with the last thing loaded on it.

That being said, here's the process.

The BLED112 dongle is essentially just a BLE112 with an attached USB connection. The BlueGiga SDK ships with drivers that allow the device to be mapped with a simple serial interface, such that the device shows up as a simple COM port (e.g., "COM16") to applications running on the host PC. The SDK also ships with two utilities - BLEGUI, and DFUTOOL - that are able to use this COM port interface to communicate with the device.

(Getting the drivers installed seems like it should be easy, but the process was finicky for me, and I ended up having to mess around with Device Manager, etc., for a while before getting the COM port to show up reliably when I attached the dongle.)

The basic process for building and installing firmware on the BLED112 is:

1. Compile your BGScript program to an image file using BGBUILD.EXE
2. Reboot the dongle into firmware update (DFU) mode using BLEGUI2.EXE
   • After attaching to the appropriate COM port, select Commands | DFU from the menu.
3. Update the firmware using DFUTOOL.EXE

Before you do this, make sure you read the "Developing Bluetooth 4.0 single-mode applications" and other technotes from BlueGiga's forum (registration required). Specifically around your project configuration:

WARNING:

If the firmware is to be installed into the BLED112 USB dongle the USB CDC configuration MUST BE included in the project file. If this is not included in the project file and the compiled firmware is installed into the BLED112 USB dongle, the USB interface will be disabled and the dongle stops from working.

Phew. Not necessarily for the feint of heart. I personally found it more appealing to shell out the money for the DKBLE112, which has the BLE112 module mounted on a board with some other accessories, and a CC Debugger for programming. With this setup, you can flash new images to the chip without worrying so much about screwing things up (there's a "reset" button on the board itself).

Other people have reported using breakout boards that are cheaper than the DKBLE112, such as this one from Jeff Rowberg. They also let you program with the CC Debugger, but I have no experience with them.

Have fun!