Something a bit more relaxing (or maybe not........)

[danhampson]

the problem at the moment is that i only have the one camera and its needed for the CG on this bird unless i can find something that weighs around the same and fits in the camera mount without loads of movement.

Ive just realized that ive glued the GPS in the wrong way around doh

[danhampson]

I've got a few more bits done over the last few days, I've gone through all the settings in the gps unit and glue it in the right way this time.

My micro minimosd arrived and has been flashed and setup with mwosd.

I've read the spec sheet on the osd and it says that it draws .5 amps, the bec on the esc is rated at 2 amps so I started to get a bit worried about the over all amp draw of the syste. So I'm putting a hobby wing 5amp bec in the craft to ensure u have enough power.

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Due to the nature of the project I've desoldered all the original wiring from the bec and replaced it.

I just need to order a flight controller with baro and mag to finish the electronics.

[danhampson]

FC ordered.
I've chosen to go with a ready made rc dodo board over a naze/flip just because the dodo has 3 uart ports which will let me run blackbox logging as well as the gps and osd, it also has a larger flash memory. I'm hoping this board will be here in the morning so that I can make a start on the FC setup over the weekend.

I've found a cleanflight development branch that is working on rewriting the navigation section of cleanflight, this branch (inav) has just made its first stable release (it's not been merged with cleanflight master repo yet.)
From what I've seen it's working very well.
This software has return to home, return to launch (auto landing) and and autonomous way point flight as well as the software filtering from betaflight.
Here's a link to the RCG thread if you would like to read more about this project.

http://www.rcgroups.com/forums/showthre ... 732&page=1

[Derek]

that really sounds incredible, Dan! Very cool!!!

[danhampson]

that really sounds incredible, Dan! Very cool!!!

In hope so.

the rmrc dodo has arrived here's a couple of shots of the board before i solder it.

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[Stambo]

Naze rev6 clone?
I got mine on the big wing and flew it, worked well but showed up the poor design, not stiff enough.
It flapped it's wings like a bird.

[danhampson]

Naze rev6 clone?
I got mine on the big wing and flew it, worked well but showed up the poor design, not stiff enough.
It flapped it's wings like a bird.

No it's not a naze clone. It's like the seriously pro f3 that Dominic Clifton released last year, it has an f3 chip built in black box, 3 X uarts, dedicated connections for led, sonar, pmw rssi and it's own built in 5v regulator (@ 0.5amps), i2c bus, barometer and dedicated spektrum sat port.

The only thing it lacks is a magnetometer (which I over looked).

I've ordered a external magnetometer which will be connected to the i2c port.

[danhampson]

Hobbytronics are the mutts nuts. I ordered @ 3.30pm and it was delivered this morning.

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This is the last part of the inav puzzle, they do recommend disabling the on board mag and fitting an external unit due to electro magnetic interference from the flight controller itself, the mag works with the interference but isn't very accurate hence the use of a external unit that can be place away from the FC.

Now to track down the data sheet for it to double check the input voltage

[Graham Lawrie]

Thats a good delivery time:)

[Stambo]

I did a video a while back about the effects of lipo alarms on a compass.
https://www.youtube.com/watch?v=37ACkzzmlDo
Anything with a magnetic field should have a similar effect.
The results were quite an eye opener and suspected to be the reason for at least one Naza flyaway.

[danhampson]

Interesting stuff Stambo.

I've been playing with this mag and gps and a aahhh!!!
It's doing my head in, the mag is installed on the wing a good 15cm away from anything else and works beautifully, until the gps is connected and the the mag has a deviation of +/- 45 degrees from the heading it was on before the gps booted up, rendering the mag useless and the wing unflyable in any of the desired modes this deviation would indeed cause a flyaway if the system went into failsafe/rth/rtl/alt hold basically any of the navigation modes as the mag is used for all of them in this firmware.

I've also found that the Ublox neo 6 gps is rubbish so to remedy the issue I've ordered a Ublox neo m8n gps with built in mag. This is the latest Ublox chip set and makes use of all gps protocols even the new galileo satellites,

There are reports on the rcg inav thread of these gps units having 10+ sat lock indoors. And even with a 10db signal loss (due to interference) still keep a full 3d gps lock.

my testing of the neo 6 has show a 4 sat lock indoors, with a 10db signal drop when connected and powered with the FC board. This signal drop with this gps unit is unacceptable as 3d lock is lost ad it will put the system into failsafe, the problem with this is that the failsafe doesn't have gps so just acts like a standard clean flight failsafe and cuts the motor/motors and the craft falls from the sky. Epic fail.

The neo 8 I've ordered comes with one of those fold away stalk things and I will be installing this on the wing to try and keep the interference to a minimum, another counter measure I'm going to take is to line the bottom of the gps puck with copper tape to try to insulate it from rf interference.

If anyone has got any other ways of of shielding the mag and gps let me know. I have thought about building a ground plane but this isn't going to be practical I this application.

The new gps should be here for Wednesday and hopefully installed by weekend ready for some more testing.

[Graham Lawrie]

I bought a JIYI and not managed to get a signal lock yet:(

[danhampson]

Have you plugged it into the u centre software?

[danhampson]

First lock can take a while especially if it's indoors, the first lock on my neo 6 took about an hour. And now cold starts take about a minute warm starts about 40 seconds and hot starts around 15 seconds.

[Graham Lawrie]

First lock can take a while especially if it's indoors, the first lock on my neo 6 took about an hour. And now cold starts take about a minute warm starts about 40 seconds and hot starts around 15 seconds.

WOW thats long:) I just tried the instructions on the site, rotating it through 360 , made me dizzy outside, will try longer when the weather gets better. But on youtube they all do it indoors?

[danhampson]

I set mine up indoors because I plug it into my desktop pc and the put the gps unit on the windows sill.
My pc is in the bedroom so I doing get little kiddie fingers touching stuff, all my other programming is done on a laptop that lives in my flight bag so it comes to the field whenever I fly.

[danhampson]

Got a bit more done tonight. After having issues with the gps and mag I decided to re flash the board and start a fresh before the new gps/mag combo arrive, as I didn't know where I was up to after messing around with loads of the settings.

Esc is calibrated. Servos going in the correct directions with stick input and gyro correction, advanced accelerometer calibration is done. Loop time is set to max/auto (500 without gps and mag). Flight pids reduced by half (recommended online for fixed wing).

So things left todo are set the gps up with the ublox software and get first lock and then and test osd is functioning properly.

I've been having some issues with the rssi and the dodo so I may just run it directly to the osd, but for that I will have to make an rssi conditioning circuit which is basically an rc filter a 1k resistor a 10k resistor and a 10uf cap. These filters can also be used to filter the power to a vtx and camera to remove noise.

[danhampson]

Neo m8n gps turned up this morning. This unit blows the neo 6 out of the water, I plugged it into the computer to configure it and get first lock. First lock took 41 seconds and that was indoors

I've lined the bottom of the puck with emi/rfi tape as a precaution and installed on the wing on its stalk.

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Because I was left with a hole in the fuse lid I decided to turn this into a vent to help draw some of the heat away from the electronics. The white plastic thing is the cap off an old asthma inhaler cut to shape.

[Derek]

That looks really really good, Dan! Too cool!

[Stambo]

looking good Dan.
I think when I crash mine I will rebuild with some sort of canopy to hide a lot of the wiring and stuff.
Yours looks so much neater.