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Daniel Wee

My little NAV/OSD project - under construction

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I would prefer to have a battery, but a smaller one would be nice. I wonder what the current draw is on the EB-85A in battery backup mode? An Ultracap style (1 farad capacitor) might just do it. I've also seen smaller backup batteries in other GPS modules (with solder tabs).

rimb05

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From a cold start, the EB85A can acquire satellites in under one minute. Is the battery is necessary?

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I wonder what the current draw is on the EB-85A in battery backup mode?

The datasheet doesn't say it, but in similar devices it's usually in the few microamps range.

The EM411 has a tiny cap (about 4mm diameter x 1mm thick) and will keep its settings for weeks/months with it.

Knowing that for the EB85 as Mr.RC-Cam says it's not really necessary (I don't use it most of the time) I wouldn't waste that much space. But a really small cap that would hold like one day might be cool not to have to wait at the field (it has taken me much longer than one minute at times, about 2 to get a lock with a wrong altitude, and about 2 more for the altitude to become correct). After a few hours even with a battery the advantage won't be really noticeable next to a cold start.

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Yes, I agree. An hour or two of backup is plenty. I've had to wait 2-3 minutes for a cold start. It just makes it quicker to have a warm start if you're changing lipos often in between flights.

rimb05

Edited by rimb05

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Exact, or just a home position reset... VERY annoying if you have to cycle power to all the stuff just to reset home position like with the IFOSD, and have to wait for 5 mins... the 10 seconds that are needed with a backup sound much better :)

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The compiler I'm using is the MikroC for dsPIC by MikroElektronika. I believe this could be the cheapest dsPIC compiler out there. Alternatively you can use the MicroChip C30 compiler but you will need to port some MikroC library functions, notably the EEPROM write (I've not yet look at the C30 compatible offerings). That one is free but loses its optimizations after an evaluation period of about 30-days I think. I also do not know what the compiled image size will be and if it will fit ultimately as I am coming close to 95% usage of available program space.

In the long term, I would like to further optimize the code to make it smaller and free up program space for other functions. Right now I just want a stable system and it is very stable at the moment.

Daniel

p.s. I've just added the reset of the HOME location to the menu in version 4.1. I've not tested this though.

Edited by Daniel Wee

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Thanks Daniel !

Edit: just installed the demo of the mikroElektronika compiler and took a short look, must say an impressive IDE. Was surprised that mikroElektronika is here in Europe in Belgrad :). Btw. have/had you also a DevBoard in use from mE ?

//Erwin

Edited by helitron

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Hi Erwin,

You can't use the Demo for this project as our image is way too big for the evaluation limited output size. I also did not use the demo board as I am quite familiar with microcontrollers and didn't want to spend more money than necessary - remembering that I'm not really earning anything from this yet.

Daniel

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Hi Erwin,

You can't use the Demo for this project as our image is way too big for the evaluation limited output size. I also did not use the demo board as I am quite familiar with microcontrollers and didn't want to spend more money than necessary - remembering that I'm not really earning anything from this yet.

Daniel

Daniel,

I know of course that the 6kB output possibilities of the demo is too low, was only curious of the IDE :).

In your case you're right of course not to buy a demo board but I hope you're able in the future to earn a little bit from the DragonOSD :). Why not ?

//Erwin

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Btw. have/had you also a DevBoard in use from mE ?

//Erwin

I currently have the EasyPic4 board and i love it. Will probably order the programmer for the dsPics from ME so i could play with Daniels code.

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The mikroElektronika boards seem very useful for me also so far but after 30 years of embedded controller programming I shouldn't need such a board anymore, when the original hardware (DragonOSD) is available already :D.

//Erwin

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True indeed.

I am just too lazy to check if there are already DIY dsPic programmers and how well PicFlasher from ME uses them.

Daniel, have u used ME's flasher? or does it only work with ME boards/programmers?

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Actually I use the Olimex ICD2. I compile to a hex file and program the device with MicroChip's MPLAB IDE. Of course, in so doing, I give up the debugging features but when you've done stuff like this long enough, you should be okay.

Daniel

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That one is free but loses its optimizations after an evaluation period of about 30-days I think.

Hmmm ARRR MATTIE, let me gives ya a little assistance land lovers !!!!!! Ok you didn't hear this from me ok, but you can download the best "Try Before You Buy" program (actually any program) out there and go to (again you didn't get this info from me) www.astalavista.com .Get the crack, patch or serial numbers there. Make sure to clean your PC with Adaware and Spybot after, they seem to leave little tracer buggies in your computer after viewing a few pages. Use this at your own discretion and ignore the naked ladies having sex! They just use them to help fund their website. ;) Or you can buy the programs like me! :D

Edited by JMS

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Okay, for fun, today I did another flight - video isn't that great though because of the time of the day (early morning) and I was flying into the sun for half the flight. The objective was to fly to a small island and come home. It's the first time I flew from that site so I made a few mistakes (look for botched landing, plane undamaged though). Also, reception got bad at the end due to trees getting in the way of the signal.

Track3.jpg

And the video:-

Island flight (65MB, WMV)

The video quality could be better but the lighting of the sun seemed to cause quite a bit of white balance shifting. Plus my DV recorder has some compatibility issues with the camera. I need to be looking for a new camera soon, hopefully.

Daniel

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That video would of made a top hit if you had flown later in the day. Great scenery and a little cloud shot as well. Oh I bet you planned that landing :D just kidding Daniel :D

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Hi Daniel, nice music! Good choice! :-)

Regarding the Camera, I suppose you used the KX-131. I did some comparison tests with another cam, the Mintron MTV-54C2AP (22x26mm / 5V), which is very similar to the KX-131. Here's a short summary of the advantages and disadvantages of them:

MTV-54C2AP: + Automatic White Balance, warm picture with very natural colors

+ Wide Dynamic Range (You see much more detail in dark

areas when flying into direct sunlight compared to the KX-131)

-+ No case, therefore only 11gr weight

- in low light conditions more noise compared to KX-131

KX-131: - "Cold" picture, the white balance tends to to give the picture a

blue/green tint

- Poor BackLightCompensation, when flying into direct sunlight,

most remaining areas of the picture are just dark.

+- Solid Case.Excellent shield, but heavy (31gr)

+ in low light conditions clearer picture compared to MTV-54C2AP

So when Backlight Compensation or Good White Balance and Color Temperature is an issue, the MTV-54C2AP is most definitely worth a try.

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+- Solid Case.Excellent shield, but heavy (31gr)

Depends, I've always used the uncased KX131 version, much lighter too ;)

And BTW I haven't managed to break one yet :lol:

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Since we're on this subject, would you guys be interested in a camera like this:-

SONY 1/3" colour CCD

Cased, dimensions 20mm x 20mm x 20mm

3.6mm lens

0.05 to 1.0 Lux (for both night and day use)

420 TVL

If I could get hold of a bunch of these, would you guys be keen?

Or would you prefer:-

SONY 1/4" colour CCD

Cased, dimensions 12mm x 12mm

3.7mm pinhole

0.05 to 1.0 Lux (for both night and day use)

420TVL

or

SONY 1/3" colour CCD

Cased, dimensions 16mm x 16mm

3.6mm lens

0.05 to 1.0 Lux (for both night and day use)

420 TVL

These come with electret microphones so you won't need to buy them separately. The all run off 12V (spec'ed but possibly runs a bit lower) Get a ruler out and check those dimensions out. These are possibly the smaller CCD cameras out there. Even the 1/3" CCD is smaller than the KX-131, and would fit many cockpits more easily. Making pan/tilt assemblies would also be easier with the smaller size. Would something like this be what you'd like to get?

Daniel

Edited by Daniel Wee

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I'd want one of each to test them and then make up my mind :lol:

As usual with cameras, impossible to tell anything about the quality from the specs...

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I know, from what I've seen, they're pretty good (the 12mm one). I will be testing these myself soon and I am expecting it to be as good as the KX-131 if not better.

Daniel

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