Preliminary RF Tests

Today I did some testing on the RF side of things,  nothing scientific, just walking around the house seeing if it would dropout or report bad checksums, I’m happy to reports all is working as expected (using the 915Mhz RFM12B module)

The tests are done by using the RFM12B Example sketch found in the JeeLab RFM12B library by Jean-Claude over at Jeelab (RFM12B Arduino Library)

This library runs unmodified on the wireless widget board, just follow the instructions in the README about setting up node ids.

From the preliminary testing using some compact 1/2 wave GSM 900MHZ/1800MHZ antennas (http://www.dealextreme.com/details.dx/sku.5237)  I’m easily getting all the way around the house with no dropouts, have yet to do outside tests.

Eagle3D

These are components I’ve created for Eagle3D.

You may also want to check out the tutorials on how to create your own components.  http://blog.everythingrobotics.com/tutorials/eagle3d-tutorials/using-google-sketchup-to-create-components/

Components

HopeRF RFM12B SMD 433Mhz/915Mhz RF Module

RFM12BSMD

Microchip MR24J40MA FCC Approved 2.4GHZ 802.15.4 RF Module

MRF24J40MA

Sparkfun SMA PCB Edge

SMA_FEMALE_PCB

PJ-326 3.5mm Jack http://www.switchcn.com/

PJ326

900Mhz GSM SMA Antenna attached to PCB SMA Connector

SMA_connector_antenna_hor

Downloads:

Strobit Eagle3D Library (19/03/2009) Download

Links

Disclaimer:

These are provided AS-IS and may contain bugs and or discrepancies and may not be to scale.

If you find any bugs or problems or make enhancements please feel free to contact me so I can update the downloads.

Strobit Google Sketchup Models

I’ve been playing around with Googles sketchup over the weekend and have created some components, one the RFM12B module and a basic camera hotshoe to scale.  It’s been a great little exercise in learning both Alibre and Sketchup as I’ve been wanting to get some 3D modelling practice, I’m finding that it’s easier to create things in Alibre and then export them to Sketchup.  Alibre does not support texture mappings in the drawing or export to POV, but Sketchup does it brilliantly, while on the other hand, Alibre’s3D modelling is very easy to use.

Currently the workflow is:  Model in Alibre –> textures in Sketchup – > POV Rendering– > Eagle3D Components.

Keep an eye out for more to come.  I’ve started a Stobit Collection in Googles 3D warehouse  for use with this project and will be adding to it as I go.   I’ll be putting the Eagle3D component files that I’ve created online shortly.

Follow me on Twitter / Strobit Update

I know I’m a bit slack in updates on the blog.  If you haven’t noticed I now have a twitter account  http://www.twitter.com/madeinoz so you can follow what I’m doing when it’s not getting updated here.

However since the blog is way over due for an update here is what’s been happening in a nutshell.

Strobit Trigger:

I have finally gotten off my butt and done a redesign (hah and you thought the project had died a slow death, it may have stalled slowed, but certainly not dead!)

Features worthy of note in the new design (in no particular order):

  • 3V design, will run from x2 AA Alkaline or single CR123A 3V battery.
  • Fairly compact board, 30mm x 70mm. (without battery)  slightly lalonger on 2.4ghz design due to antenna.
  • Onboard on/off switch to save batteries when not in use.
  • FTDI 3.3v breakout cable port for connecting to either RS232 or USB using the FTDI cable.
  • Onboard ISCP port for programming.
  • Personality daughter boards.  Will allow users to create their own hardware modules, i.e. sound trigger, light trigger, LCD UI, or whatever they like etc
  • Atmega168V processor, low cost, low voltage design = longer battery life.
  • Can run Arduino bootloader, so developers have access to Arduino development libraries.
  • I’ve designed 2 different boards.  One using the RFM12B module at either 433Mhz or 915Mhz.  The second board I’m going to try a 2.4GHZ design using Microchips FCC certified MRF24J40MA 802.15.4 module, this is purely experimental so I don’t have any testing done yet, but I have some of these modules and would like to try them out, also being FCC certified will be an added benefit.  (not to mention I’ll be using these for a mesh sensor network project I have planned around the house)
  • RFM12B board design has external SMA antenna.
  • Base PCB board designs are done and I’m fairly happy with them so far, I’m just finishing a basic personality modules which I can used for testing and maybe another one so I can make up the  max designs I can have on a single panelized board (may as well get the most designs I can get fabricated when I send it off to GoldPheonix).  I’ve done some initial Eagle3D runs to get an idea of the boards and so I can post them on the blog, but I really need to learn how to create components in Eagle3D as it leaves unknown components blank, i.e. the RF modules and therefore looks incomplete.  (anyone that can help me here please contact me)

Still To Do:

  • Panelize boards
  • Send to GoldPheonix for PCB fabrication.
  • Assemble and test.

I’ve also been playing with learning Alibre, a fantastic 3D design package (they have a free version) so I can get some ideas for building enclosures design for these boards.

RFM12B PCB

image

MRF24J40MA PCB

image

StrobIt In the Wild

IMG_8198.JPG, originally uploaded by jgentsch.

The first StrobIt Triggr seen in the Wild!

Jan has made a neat and well packaged version of the StrobIt Triggr. Based on the AtMega8 it runs from a single AA battery. Well done Jan!!!

RFM12 Tutorials

Tutorials

I’ve written these “How-To” articles to help get you started in using the RFM12 transceiver module from HopeRf. I found using these modules for the first time can have a bit of a steep learning curve, so I’ve put down to e-ink what I’ve learnt and hopefully you can benefit from my trials and tribulations 🙂

Other Articles

Strobit Triggr Prototype Finished

After a hectic and very hot Christmas (41DegC) I managed to get some development time and finished 2 prototype boards.  My RFM12 header boards still have not arrived, caught up in the christmas mail I guess 🙁  So I’ve had to resort to hand soldering some wires to the header in the meantime. (Murphys law suggests that as soon as I finish soldering these headers the breakout boards will arrive in the mail)

Tomorrow/Later tonight I will test both of them and see if I can get a remote trigger happening woohoo.

Sorry about the quality of the photos as they were taken with my phone 🙁

Strobit Triggr PrototypeRFM12 HeaderRFM12 Header SolderedRFM Development