PCB designs were finally sent off to Gold Phoenix yesterday, a bit of a delay as I had been wanting to complete a couple of other designs to fill up the panel before sending off. Three different designs, Strobit RFM12B core, Experimental 2.4Ghz core and a prototype personality (think arduino prototype type shield) have now been merged using gerber merge into a 10” x 14.5” panel. Hopefully they should be back early next week.
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S.P.O.T. has just been released on Google code, a fantastic variation of the Strobit Triggr with LCD and remote control of flashes using TTL.
S.P.O.T – Strobist Project Opensource Trigger.
Well Done Till on the release!
http://code.google.com/p/strobist-project-opensource-trigger/
The Eagle PCB design files are now available for download from the Strobit Project Page. Constructive feedback is appreciated. Please treat these as an early alpha release, the PCB has not yet been verified.
I have also released the design files for a blank personality board, this can be used as a starting point for any future boards.
I will shortly have an early release of the Basic Strobist Personality board online.
As mentioned in a previous post, Bill Grundmann has been documenting his investigation into Canons E-TTL protocol. Bill has just released a PDF summarising what he has found so far.
I’ve yet to go over it in detail, but for those looking at doing some E-TTL investigation of their own this document is a must.
http://billgrundmann.files.wordpress.com/2009/03/ettl_grundmann.pdf
The Strobit Project now has some Google groups enabled. Feel free to join these and take part in the discussion. I will leave the old forums up for archival/historical purposes, but will become read only eventually.
See Strobit Project Page for the groups.
The Strobit Triggr project now has a proper open source home, a Google Code project page – http://code.google.com/p/strobit/ If you think you can contribute please join the project.
Over the next few days as time permits, I’ll be adding everything I have so far to source control for the current design.
All hardware will fall under the TAPR Open Hardware License – http://www.tapr.org/ohl.html
More success from Bill Grundmann in his attempt to decrypt Canons E-TTL protocol !
It appears that there is a consistent 4msec delay between when the CLK signal from the camera body drops to GND and when the actual flash is triggered. This would give us plenty of “leeway” in our timing to sync with the shutter I would guess.
Then next part of the puzzle is to now trick the body that it has a flash in high speed sync mode attached to achieve some high sync rates.
Next week I’ll start investigating this further (already got a pretty busy weekend on the cards )
For those of you that shoot Nikon, it might be worth looking at what Bill has done so far and see if those with knowledge can do the same for the Nikon protocol. With the knowledge of both major protocols we just might be able to have both vendors protocols talking to each other via the Strobit Triggr.
Well done Bill and keep up the great work!
Bills’ Post: http://billgrundmann.wordpress.com/2009/03/19/canon-ettl-protocol/
Seeing as I’m a canon person as far as bodies and lens goes I thought I’d look into the E-TTL protocol and how the camera body and the flash can talk to each other.
I’m not looking to completely implement the E-TTL protocol in the Strobit Triggr, (well not yet anyway), but more along the lines of fooling the camera body that I have an E-TTL capable strobe attached and thus enable high speed sync mode. If we know what the sequence is between the camera and the flash is, then I can play around with the timing of the Strobit Triggers. Why do we need to do this?
While I’m waiting for the boards I will look at playing around with this idea, I’ve just ordered a cheap canon E-TTL flash extension cord (http://www.dealextreme.com/details.dx/sku.19612) so I can gain access to the hotshoe contacts easily with my logic analyser.
Unfortunately one of my biggest stumbling blocks is that I do not own or have access to a Canon E-TTL flash, (the only non canon equipment in my kit are my strobes mix of Nikon and Vivitar), thus started some research, it just so happens that Bill Grundmann has recently started his analysis of the E-TTL protocol and making fantastic headways. Dang he has saved me a huge amount of time! Well done Bill!
Here are the final renderings from POV with the basic personality board installed, along with a 900MHZ antenna. I’m pretty happy now, looks OK and now will see how accurate this exercise really is when I get prototype boards back.
Ok not quite finished, but almost there! I’ve had to make a few minor changes. I’m glad I’ve taken the time to learn and play around with Eagle 3D, it had highlighted some potential clearance problems. Rather than rush things I’ve decided to take a bit of time modelling than fork out my $$$ and get some prototypes made only to find these problems down the track and could have avoided. Granted Modelling is not a silver bullet, and I guess I could be here forever, but now I’m a lot happier.
Changes:
Todo:
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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.
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):
Still To Do:
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
MRF24J40MA PCB
I’ve been playing around with the Arduino Diecimila and the ATMEGA168 over the last couple of weeks to better familiarise myself with the AVR ATMega168 MCU, I’ve been using PICs on and off the last few years, but the decision was made to use the ATMEGA as the MCU of choice for the Strobit Triggr project, mainly due to the open source tool chains available, and the simply programmer required.
In short I’m glad I’ve made the switch and I must say I’m loving the learning experience. I’ve moved from the Arduino software development platform as I found it very limiting and am now using the open source avr-gcc (win-avr) and Eclipse, using the AVR plugin and CDT plugin as my development platform of choice, I’m comfortable with eclipse as my editor as I’ve been using this for my Java development for the last 5 or so years.
As a task I set for myself to learn the onboard peripherals, I’ve created a Weather Shield for the Arduino, so far it has the RFM12B RF module, DS1307 RTC, HH10D Humidity Sensor, a HP03D, combined barometric pressure and temperature sensor, and soon to have a light sensor and Dallas 1-Wire interface for talking to the Dallas Weather Station that I’ve had lying around in a box for the last 10 years, (yes one of the original ones released by Dallas in 1998, I’ve been waiting to move in my house for a long time), I’ll post the weather shield design up on a separate topic later, but suffice to say, I’ve enjoyed playing with the SPI, I2C, ICP, UART and onboard timers.
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