skysea76 Posted August 27, 2011 Share Posted August 27, 2011 As I was looking into a way to fix my dongle for perfect operation, I found that most (unfortunetly mine is the cheap ROM only version, the updatable ones are EEPROM) dongles can have their firmware updated. There are firmware files available online, but, surprisingly, Apple issued a firmware update that contained a GenericCSR.duf (the kind of firmware we want). This firmware probably identifies the dongle as Apple made, and will get it to work nativley. I have not tested this however, since, as I said, I can't flash my firmware. The firmware is attached. Here is a short guide: You will need a Ubuntu Live CD. CONTINUE AT YOUR OWN RISK, I CAN'T CONFIRM IF IT WORKS OR NOT, MIGHT "BRICK" YOUR DONGLE Courusy of midnitesnake Chipsets: Whats the difference?The chipset of the Bluetooth USB Dongles are very important. Broadcom chipsets are cheap hardware and are deemed unsuitable devices for this paper. But unfortunately nowadays, every manufacturer seems to prefer putting these chips in their products compared to the more reliable Cambridge Silicon Radio (CSR) chipset. If your lucky enough to find a dongle with a CSR chipset, your going to encounter different models: * Bluecore2-ROM/EXTERNAL (BC2-ROM,BC2-EXT) * Bluecore3-ROM/EXTERNAL (BC3-ROM,BC3-EXT) * Bluecore4-ROM/EXTERNAL (BC4-ROM,BC4-EXT) You will notice each model has two distinct chipsets ROM and EXT. The ROM (Read Only Memory) chip is the cheaper version and usually only sells for $6 less compared to the EXT. The ROM is completely useless to us because we cant change the contents of its memory. The EXT or External model has a flashable EEPROM (Eraseable Electronic Programmable Read Only Memory). This means we can change the contents of the chip by using a computer to alter the firmware. Using bccmd to get the Chip Revision $ bccmd -d hci0 chiprev Chip revision: 0x0026 (BC4-External) So in the above example, we have a flashable BlueCore4-External chip, perfectly the right version for the alternative firmware obtained from the Internet. N.B. Other EXT chips may be flashable, but the firmware available will not work for them. Uploading/Downloading Firmware to/from the BT USB Dongle Other hackers on the internet have made the alternative firmware freely available for download and the files are in the format of a Device Format Upgrade (DFU) file. You can then use on Linux the opensource tool dfutool (only works with CSR devices), to backup your original firmware, and download the alternative firmware onto your USB dongle. Backup existing firmware $ dfutool archive old_firmware.dfu Download new firmware $ dfutool upgrade new_firmware.dfu GenericCSR.dfu.zip 2 Link to comment Share on other sites More sharing options...
steenamaroo Posted January 15, 2015 Share Posted January 15, 2015 Hi there, I just wanted to post here to thank you for this information. I bought a DB120 b3 because the bluetooth reception is awful with 2009 mac pro. (Mavericks and Yosemite) The dbt120 dongle worked perfectly with a mighty mouse but once I introduced an apple BT keyboard the mouse would disconnect and reconnect after exactly 6 seconds of inactivity. It remained connected if I constantly moved it around. My firmware version showed as 443 in sys prof and, after following your guide and using the genericsr.dfu extracted from firmware updater 1.2 (PPC only), I'm now seeing firmware version 1586. I don't know anything about other features or improvements, but I'm no longer getting disconnects. Many thanks. 1 Link to comment Share on other sites More sharing options...
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