#155 – An Interview with Jeff Rowberg – Mini Module Master

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Welcome, Jeff Rowberg of Bluegiga Technologies and the KeyGlove Project!

• 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.
  [tube]http://www.youtube.com/watch?v=AacoxHFYvZw[/tube]
• 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.
  [tube]http://www.youtube.com/watch?v=OPethpwuYEk[/tube]
• 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.