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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