Archive for the MESH Category

Blimp

Posted in Air, Android, Arduino, Hardware, Locomotion, MESH on March 28, 2013 by asteriondaedalus

So, one project that has always been on the back burner is a submersible.  Now the reason is simple, electricity and water don’t mix.  Still, as discussed in News Splash , that is on its way.

However, in the meantime the closest thing to having to deal with movement in a fluid is a blimp.  Various ideas for RC blimps are around but I wanted a cheap vehicle to get into it (and to have something to give my nephew to get him into electronics and robotics).  Blimps are actually quite expensive to buy so I thought on it and one day, down by the beach at a $2-shop I saw and bought a pool toy.  I figured I needn’t be serious about it, but also the molded-in handles actually gave me a good place to hang any gondola that would be slung under it.

blimp

Of course, the flight control will be via an AIO.  I can then stage development, first RC than semi-moving-onto-full autonomous.

AIO

Now you can buy a daughter board for the AIO to carry your XBee and GPS but I opted for a dual XBee shield.  I will remove the pins used for mating to Arduino boards.  The prototyping area will be handy and the two XBee sites will be used, not by XBee RF module of  course but a Synapse SNAP module and a XBee as Bluetooth module.

dual xbee

The Bluetooth will be to talk to the on-board Android phone that will eventually hold the Autonomy.  Initially it can provide the camera and the GPS.  The phone can also act as the Bluetooth hub for indoor work or talking directly to my computer or tablet by wireless.

water proof phone

To push the blimp through the air I have ordered vector thrust units.  I will have two up front to gimbaled the vertical axis for aileron/elevator mixing and a single pusher at the rear, gimbaled in the horizontal to give “rudder”.  That is, that will be the initial configuration.  The power train configuration, especially its location etc. will need to be the focus of some experimentation.

gimbal

I got cheap ESC to start, they will only do for outdoor or restricted indoor work.  I’ll need reversible ESC to allow the blimp to back out of trouble when maneuvering indoor (eventually).

HK-12A… more to come as project comes together.

Impish!!

Posted in Hardware, MESH on October 11, 2012 by asteriondaedalus

Go figure, yet another piece of wifi genius.  Imp!

Impish!!

Impish!!

Snapping it all up

Posted in Hardware, MESH, Prototyping on August 28, 2012 by asteriondaedalus

So, a rough start to using SNAP but a good bit of understanding now.

One exciting discovery is the SNAP Connect Python code has had a change in licensing and you can use it FREE for up to 10 nodes (not including Portal or the PC root node).

I have been looking at integrating SNAP networks with ROS and ROSPy seems to be the go – but I really need to build a LINUX box so …

Along with the ROSPy there are various other libraries I have been grabbing for rpc in Python and connecting to CORBA (OmniPy for OmniORB).

The SNAP connect can be used over networks yadda so pretty cool (I am thinking of introducing my nephew to robotics and the ability for him to control things my end or me to upgrade software at his end is a great feature – we live about 1000km apart).

DESIGN DECISIONS

Now that I am flying with SNAP I am looking at a basic bit of code to run on the Flyduino to allow me to run it remotely via the SNAP Connect Python code.

Ahead of this I have been looking at the schematic and, while it allows for 12 servos to be controlled, I will limit this to 9 to give me the SPI channel.  Also wik, while the Flyduino provides 8 Analog in I will look at whether I can keep pins 27 and 28 for an I2C channel.   This will allow for some smart sensors on the Swash Bots.  This will allow for gaits to be run from the PC until they are too finely tuned.

Also 6 servos and use D8, D9 and D10 for chip selects for the SPI bus or inputs for bumpers … oh yeah, already decided on visual odometry.

The little board is actually quite flexible, below is the SNAP RF266PC1 (XBee clone) sitting in the socket.  I am looking into the simple mods to allow (perhaps) programming the Flyduino wirelessly.

flyduino

Snap (by Synapse)

Posted in Hardware, MESH on June 29, 2012 by asteriondaedalus

11279-01_large

Specs:

• 15 GPIO, 4 with 10-bit ADC
• 128k flash, 56k free for over-the-air uploaded user apps
• One UART port
• Low power modes: 2.3 ?A w/ internal timer running
• Spread spectrum (DSSS) technology
• Socket-able or solder-able
• Up to 2 Mbps Data Rate
• 2.4 GHz RF Frequency
• Receive Amplifier (10 dBm) standard
• Transmit amplifier (20 dBm) for best-in-class range
• Chip antenna (up to 4000 feet, LoS at 250kbps)

SNAP’s on-board Python interpreter provides for rapid application development and over-the-air programming

I was poised to buy the ZIGBEE modules for a couple of my ZIGBEE mounts when I came across the SNAP alternative.  A plus because they have ZIGBEE footprint.    A plus because they come with a cut down version of python on them and allow for RPC and a whole range of useful things, over the wireless.

Of note, they appear to allow for the raw data flow transparency under the RPC and other layers so I can still use them for MAVLINK as well as using them for other smart applications.

The most useful thing is that, plugged into the arduino boards, they can offload the raw I/O to the arduino board.  The remote programming (over the air) will allow for more malleable smarts – especially as a PC can join in and act as a node using full python.

OR, at least, they can be used simply as a ZIGBEE replacement.

I have two on order to start looking at the MAVLINK side.  Noting, of course, that MAVLINK already has python bindings.