P-Mag capability demo

Brantel · #1 02-16-2011, 11:53 AM

Moving to the 21st Century with my airplane's ignition system has brought some benefits...

I built this simple LCD display that ask the P-mag to start streaming ignition data upon startup and then parse the data and display it on a simple 4x20 backlit LCD screen.

The results are shown below. I am not going to go into details on how and what it takes to do this because I do not want to have this compete at all with the EI Commander that Bill Repucci has developed. My device only monitors the P-mag. The total cost to go from P-mag to what you see in this video is $44.45 and over half that is the LCD (no I am not planning to sell them)...

If you are a tech geek and would rather play with electrons than eat, build you one but if not, get the one that Bill Repucci sells. Also buy his if you want to control the P-Mag (that could be expensive if you screw it up playing around with a device like this)

Disclaimer, the data displayed in this example is strictly sample data only and does not mean anything!!!

http://www.youtube.com/watch?v=Bo5HLxaXPbQ

N941WR · #2 02-16-2011, 04:02 PM

Brian,

That is really nice.

Quote:

Originally Posted by Brantel

...
If you are a tech geek and would rather play with electrons than eat, build you one but if not, get the one that Bill Repucci sells. Also buy his if you want to control the P-Mag (that could be expensive if you screw it up playing around with a device like this)...

Thanks for that and I caution you and anyone else who wants to play with the E/P-mags. It is very easy to issue a command that can either shut the E/P-mags off or screw up their timing.

We spent a lot of time working on the EICommander so that it wouldn't shut your ignition down in flight and if you wanted to make timing changes, you had to step through them, one notch at a time.

Brantel · #3 02-16-2011, 09:12 PM

Before reading on below...head Bill's warning above. I am not responsible if you screw up your ignition!!! Keep in mind that my project is for MONITORING only and other than commanding the P-Mag to go into stream mode, I do not write anything to the P-Mag. If you decide to write to the P-Mag, make sure you know what you are doing!!!

I have talked to Bill and he is fine with this as a personal project and we agree that this fun project and his EI Commander are different enough that it should not impact him so here goes:

This thing is self contained and can run off of a 9 volt battery or lighter plug or ship power. It all will fit in a project box the size of a pack of cigarettes.

Emagair already has a free software program that will run on a laptop that monitors their P-Mag but for me that is too big and bulky and a real pain. Not to mention hard to see outside in the bright light.

Here is what I am using:

An Arduino based microcontroller board, very inexpensive and very powerfull
A LCD117 Serial LCD microcontroller board, very inexpensive and has a great built in library for the serial LCD screens
A TTL to RS232 converter board, required and cost nearly nothing
A 4x20 Blue LED Backlight Serial LCD screen, awesome and inexpensive
The above and some code and the sentence structure/command codes from EMagAir is all you need to make this thing work....

That is it......simple hu??

I will answer any questions I can. I am not at liberty to give out the command codes or sentence structure provided to me by EmagAir. If you want em, contact those guys yourself.

Once I test this code for a while, I might be persuaded to load it onto your Arduino for you but I will not give out the source code since it contains the command codes and sentence structure.

This was a "for fun" project for me and I do not intent or want to make money off of it....I have another fun project in store for the Dynon!!!

petehowell · #4 02-16-2011, 10:32 PM

Brian - that is very cool!

If we could only convince the guys from Dynon to display the PMag params on the EMS we would be really talking. Better yet, allow a EiCad-like interface from the EMS!

I know, I know, it might be dangerous - but it would be cool!

erich weaver · #5 02-16-2011, 10:55 PM

Quote:

Originally Posted by Brantel

That is it......simple hu??

Ummmmmm, yeah, simple. So simple that only you and Bill have done it.

No worries about ME sending commands to my Pmags

Erich

Brantel · #6 02-17-2011, 05:31 AM

The guys at EmagAir have stated that they have made their protocol available to the EFIS makers but as far as I know none of them have took that ball and ran with it. Even if they did not want to program the P-mags, they could display the data like I am only in a graphical way. That would be kid stuff to them....

Quote:

Originally Posted by petehowell

Brian - that is very cool!

If we could only convince the guys from Dynon to display the PMag params on the EMS we would be really talking. Better yet, allow a EiCad-like interface from the EMS!

I know, I know, it might be dangerous - but it would be cool!

Brantel · #7 02-17-2011, 06:01 AM

Quote:

Originally Posted by erich weaver

Ummmmmm, yeah, simple. So simple that only you and Bill have done it.

No worries about ME sending commands to my Pmags

Erich

It really is simple (ok the code is not trivial but the hardware is!). I took a pic of what it takes to do this. The hardware is available for the most part fully assembled but it is easy to put it together out of kits or raw parts. There are many versions of the uController boards out there and mine is not the most basic one. You can get em even more bare bones depending on what you need.

Here is my setup:

The white board on the breadboard is the uController, the red board attached to that is the TTL to RS232 converter board.
The LCD can be remote mounted or not. It has a daughter board on the back of it that contains the controller for it.

The age of that breadboard makes me start to feel old!

Here is a really bare bones version of that same uController board that is available:

CMW · #8 02-17-2011, 12:26 PM

Brian, that is really cool! Is the communication protocol available somewhere?

-Chris

Brantel · #9 02-17-2011, 12:56 PM

It is just ASCII text streaming out of the P-Mag. The command codes and structure are available from EmagAir. I am not at liberty to share those directly.

Brantel · #10 02-17-2011, 01:00 PM

Lots of people are asking where to get these parts....

I bought all mine thru http://shop.moderndevice.com/

Their stuff seems well thought out and works great.

uProcessor Board

4x20 Blue Backlit Serial LCD

LCD117 Daughter board/processor for the LCD

TTL to RS232 adaptor board

If you want to program over USB, you will need this USB BUB board. Not required as you can also program over the serial adaptor as well.

Note: Most of the above is available in raw components, as well in kit form and fully assembled and tested. The price for fully assembled and tested is a little more but not much....
Lots of options out there...