Date: 5. Mai 2015

Author: Sebastian Herp

• hciconfig => if it shows the interface to be down execute "sudo hciconfig hci0 up"
• sudo hcitool lescan to scan for BLE devices
• gatttool -t random -b F0:0E:BD:D9:5B:3D --interactive to start gatttool
• connect => command line should change to blue and you should be connected to the Blend Micro with the address F0:0E:BD:D9:5B:3D
• char-write-req 0x0011 0100 asks for notifications opening the return channel (status messages, encoder position and button presses are received here)
• char-write-cmd 0x000e 00 asks for a status reply
• char-write-cmd 0x000e 01ff00 sets the red LED to full brightness (0100ff: green LED full brightness, 018080: both LEDs half brightness, 010000: both LEDs off)
• disconnect / exit to disconnect from device

• Status: "00 00 06 00 00 0d 75 20 00" (encoder pos = 00 06, leds = 00 00, voltage = 0d 75, bat. percentage = 20, running on USB power = 00)
• Encoder movement: "01 00 10 01 5a" (encoder pos = 00 10, speed in deg/s = 01 5a)
• Button: "02 01" (button pressed) and "02 00" (button depressed)

Since the Blend Micro always draws a minimum of 1.7-2.0 mA ( http://redbearlab.com/blend-low-power-settings/ ) a external latching power switch is used. It is activated by USB power, button press and the Arduino Pin D5 being HIGH.

The Blend Micro deactivates itself after a long button press or the battery running below a certain voltage (default 3.4 V) for some time (200 s) while not connected. It also deactivates below ~3.1 V because the gate voltage on the NPN transistor will be to low.

While running power is saved by sleeping during periods of low activity. The Arduino wont sleep when connected to USB power, a LED is on (PWM, not full brightness) and certain other conditions to make sure debounce, etc works. The LEDs will turn off after a configurable amount of time (default 30 s) to save power.

• Off: 0.0 mA
• Startup: 12-16 mA
• Sleeping: ~2.5 mA (BLE still on in this mode)
• Encoder movement or putton press: ~6.1 mA
• LEDs:
  • red = FE: 15 mA
  • green = FE: 10 mA
  • both = FE: 17.4 mA
  • red = FF: 11.9 mA
  • green = FF: 6.3 mA
  • both = FF: 14.7 mA

• Install Arduino 1.6.3+
• Change the Skechtbook location to the Arduino directory of this repository
• Done

• Copy Raspbian Wheezy (2015-02-16) on a SD card (use Win32DiskImager on Windows)
• Follow the instructions here to install Bluez 5.30 on Raspberry Pi
• gatttool, hciconfig and hcitool should now be available on the command line

• http://redbearlab.com/blendmicro/
• http://redbearlab.com/getting-started-blendmicro/
• http://redbearlab.com/blend-low-power-settings/
• http://www.arduino.cc/en/uploads/Main/arduino-leonardo-schematic_3b.pdf
• https://github.com/RedBearLab/Blend/
• https://github.com/RedBearLab/nRF8001
• https://github.com/NordicSemiconductor/ble-sdk-arduino