- BlueGiga has a proprietary BT stack called the iWRAP stack
- Bluetooth itself has a bunch of different profiles. Some of the ones discussed were:
- HID – Human Input Device
- SPP – Serial Port Profile
- Sparkfun now carries some that are single profile devices, such the BlueSMiRF Gold
- These are based off modules by Roving Networks
- There are 2 halves of a BT stack
- Controller (the radio and HW)
- Host (network interface)
- Most communication wi
th the modules is through a UART connection.
- The BlueGiga modules use the CSR chips BlueCore line. This is an XAP processor and the low level utilizes the BlueLab dev environment.
- Chris asked about the TI family, such as the CC2541 by Texas Instruments. This is actually integrated on other BlueGiga modules.
- Jeff has been selling breakout boards through InMojo, a marketplace site for OSHW. It preceded but is similar to Tindie.
- Chris points out that Jeff made the unusual transition from software to hardware. Jeff blames the Arduino and the face that his dad was an EE.
- Growing up, Jeff worked on TRS80 and Graymark kits with his father and brother.
- The KeyGlove project was not directly influenced by the Nintendo Power Glove. This was prominently “featured” in the 1989 film, The Wizard.
- Jeff is interested in wearable computing (obviously) and is in the Google Glass Explorer program, same as Chris.
- It was at the Google I/O “Voiding your warranty” session where he decided to start hacking at getting the KeyGlove to interface to Glass.
- Windows 8 has an odd way of adding unsigned drivers, which the Android environment is right now for Glass.
- The KeyGlove kickstarter is still working on delivering prototype units, nearly 2 years later.
- Keyglove fabric interface is tough. Chris suggests Jeff talked to Hoeken about his keyboard pants. Jeff has talked to Lynne Bruning in the past about conductive fabrics.
- Aside from working on KeyGlove and at BlueGiga, Jeff has also been working on a standardized library for interfacing to I2C parts with not-so-transparent registers. This is all documented at i2cdevlib.com.
- The device that started it all was the Invensense MPU6050.
- It has been co-developed with Noah Zerkin, who is a wearable computing enthusiast. He also was the one to take the picture of Sergey Brin wearing Glass on the NYC subway.
- Debugging and reverse engineering the I2C bus was assisted by the Saelae logic analyzer by watching a dev board boot and monitoring packets between the dev board micro and the chip.
- The database driven register map is a great way of visualizing register sets, without using Excel.
- All code for this open source project can also be found on GitHub. People are also working on porting to other devices like the MSP430.
- When asked about why Google doesn’t already have Bluetooth Low Energy support, Jeff guessed it was because they were counting on the alternate standard, ANT+which never took off.
Many thanks to Jeff for answering all of our questions about Bluetooth and interfacing with modules that implement the standard! Follow Jeff on Twitter, @SectorFej.