ANN: Freerunner Navigation Board v2 is finally available

Christoph Mair ml at chonyota.net
Sun Sep 12 20:24:31 CEST 2010


Dear list,

after lots of hard work I'm happy to announce that the Freerunner Navigation
Board v2 is finally available! The team from handheld-linux.com [1] kindly
offered to handle orders and shipping.

The second version of the Navigation Board includes some features which go
well beyond of what is needed for navigational purposes. The board comes in
two assembly variants "standard" and "complete". See below for a feature
description/comparison. The most recent documentation as well as possible
use cases and bug descriptions can always be found on the wiki page [2].

Features supported by any board:
* 3D magnetometer
    The magnetometer measures magnetic forces on three axes. With some
    math it can be used as a compass. Alternatively, use it to measure the
    magnetic fields generated by trains while accelerating
    (e.g. underground lines).

* 3D gyroscope
    A gyroscope measures angular velocity. It can determine how fast you
    spin your Freerunner around its three axes. Usable to support the
    integrated accelerometers for inertial navigation (navigation without GPS)
    or to create a wireless game controller (like the wii).

* Barometric pressure sensor
    The change in ambient air pressure is a good indicator for changing
    weather conditions. If the weather is relatively stable and the barometric
    pressure changes, it usually indicates that the height above sea level
    changed. If this value is known the absolute height can be calculated
    without using the GPS.

* Four channel LED controller
    This LED controller can dim and make blink up to four LEDs (e.g. RGBA). It
    works autonomously, even if the main CPU is suspended. This may for
    instance be used to indicate unread messages. Large blinking intervals and
    duty cycles enable short flashes to save battery power. Alternatively one
    could connect a high brightness LED and  use the Freerunner as a dimmable
    torch.

* Seven channel touch controller
    The chip could actually control twelve channels, but due to space
    restrictions only seven are available on the FRNBv2. They can be used to
    add touch buttons to your Freerunner or act as proximity detector.
    E.g.: disable the screen lock if you pick up the phone. (*) Four channels
    can also drive LEDs, if you don't need them for something else.

Additional features of the "complete" boards:
* 12-Bit analog to digital converter
    This chip is very similar to the one used on the Freerunner Navigation
    Board v1 to digitize the output of the gyroscopes. The FRNBv2 does not
    use it for own purposes, it's completely under users' control. A possible
    use cases would be an ambient light sensor. Or use it to measure the
    current consumption of the FRNBv2 ;-)

* Programmable oscillator
    Do you need to generate a rectangular signal with programmable frequency
    between 1kHz and 68MHz? Then this chip is made for you. What can you use
    it for? I thought about a 38kHz oscillator which can be enabled and
    disabled using a GPIO pin. This could be used as generic infrared remote
    control.

If you really need these two last features, order a "complete" board or add
the chips yourself to any "standard" board. They come in leaded packages and
are hand solderable if you have some soldering experience.

(*) This feature was not tested yet due to a missing kernel driver. I'm not 
sure if it will work as expected.
(**) The programmable oscillator does not work due to a strange bug. See the 
wiki [2] for details.

Have fun!

Christoph

[1] http://www.handheld-linux.com/wiki.php?page=Navigation%20Board
[2] http://wiki.openmoko.org/wiki/Freerunner_Navigation_Board_v2



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