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That's the hard bit done, you'll be flying at the weekend. I was going to suggest you might want to consider flipping the power distribution board to protect the wires when pushing the battery in and out ( I built mine like yours but in hindsight would flipped it ) but I see you have threaded the ESC wires through the struts before soldering, so maybe not practical now.

Very neat. Nev.

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Posted by Biggles' Elder Brother - Moderator on 22/05/2015 22:44:32:

Great news! So that's two up!

BEB

Make that three, and I'm not counting the time 2 weeks ago when it flipped over backwards.
but with new props via ChinaPost, it's hovering a treat. Remember, I'm using the less sophisticated KK2 board.

Thanks for the project BEB.

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Well, time to start fitting the GPS system to our drone. First lets introduce the bits and pieces we will need to get this up and working.

The first job is to connect the GPS to the computer, test it then set it up at the right baud rate etc.
How do we connect these things together? Basically, as I said in the video, there are four wires:
1. A data send (Tx)
2. A data receive (Rx)
3. A power feed at +5V (Vc)
4. A ground (GND)
When connecting either the GPS or the I2C board to the FTDI card (and so on to the computer) the basic principle is to connect the power lines one to another, the ground lines one to another and then to connect the Rx of one to the Tx of the other and vice versa.
So the connection between the GPS module and the FTDI looks like this:
wiring.jpg
The video below shows the process of connecting the GPS to the computer:
So with this connected the next thing is to download a piece of software: The GPS test and configuration software, you can this here
Connect up the FTDI, note the com port - my case it was COM PORT 10, the follow the instructions in the video below and you should witness your GPS actually working!
So, we have a working GPS, now we have to set it all up.
BEB
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OK, so the GPS works - but it won't do much for us yet!

We need to download the software that will link the GPS via the i2c board to the Multiwii. We can find this here. From there we need to download and extract the folder:

I2C_GPS_NAV-v2.1r2.zip

Keep this safe - we will need it again later. For now we want the text file:

u-blox-config.ublox

Store this and go to the GPS testing software we downloaded in the previous post. Connect the GPS. Then select 'Tools/GPS Configuration', the software will prompt for a file - give it the one we have just downloaded, then click the 'File to GPS' button on the dialogue box. The text config file will then update the GPS and set its baud rate at 115,200 - which we need it to be for the Multiwii.

Now disconnect the GPS from the computer and reconnect it - you will find that it won't work!! This is because the software is still set at the default speed of 9,600baud - but we have updated the GPS to work at 115,200 baud - so they won't talk to each other. Easy to fix - select 'Receiver' in the GPS Test application and set the application speed to 115,200baud, restart everything and it should work again.

So, that's the GPS set up done. Next we have to set up the I2C board.

BEB

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We now need to connect the I2C board to the computer. The board will have come with a 6 pin array, you have solder this to the row of six holes at the side of the board labelled 'FTDI'. Yes,....you heard right - solder!

Now I don't know about you but give me an undercarriage to solder or a whopping great 8AWG wire into a connector and no problem - I'll have it done for you in a jiffy! But electronics soldering on a surface mount board!!! EECK!!! Its very small - magnifier in hand - I went for it with my smallest bit on the iron and the temperature set down at 250C. Phew!

Once that is done I needed a way of connecting these pins to the pins on the FTDI board. I was a bit short on thin wire - so I took a length of Futaba style servo lead and another length of JR style servo lead. Separated them into individual wires then crimped female servo plugs on either ends - hey presto, instant connections. Connecting the I2C board to the FTDI is exactly the same principle as with the GPS - +ve to +ve, GND to GND, and then swop over the Rx and Tx. The picture below shows the general idea:

i2c connected to ftdi.jpg

And now we can update the I2C board,....but that will have to wait as I ran out of time there for today! Back soon.

BEB

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Good stuff BEB.

I'm afraid I have to report a motor problem. One of them stutters a lot on start up and overheats massively.

I've tried all the usual tricks to loosen the bearings, check connection quality etc etc. I even swapped it with one from another leg, and the fault followed the motor. Another is getting too warm even after 30 seconds at tickover, so I think I'll be buying upgrade motors soon so I can get on.

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Posted by Martyn K on 01/06/2015 09:42:59:

I agree

Not really interested in quads - or at least I wasn't - until this thread started. I'll be spending some beer tokens - probably next pay day

Exactly the same for me - excellent little project. And, if I read it correctly, you get an MSc if you complete it successfully laugh

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You'll find this a doddle Martyn! - I know that you have played with Arduinos before, on robots I believe. Very similar as you can see - I suppose in essence a drone is just a flying robot!

Good news you're going to have a go Richard - and I think this is a great potential way to interest youngsters in flying generally because the high level of computing content tends to appeal to them.

One thing I would stress to anyone thinking of having a go is that it is much harder to explain this stuff than is it to actually do it! Once you have the kit in front of you and get the software up on the computer everything makes a lot more sense and you can clearly see what you have to do.

BEB

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Posted by Masher on 01/06/2015 10:55:09:

Posted by Martyn K on 01/06/2015 09:42:59:

I agree

Not really interested in quads - or at least I wasn't - until this thread started. I'll be spending some beer tokens - probably next pay day

Exactly the same for me - excellent little project. And, if I read it correctly, you get an MSc if you complete it successfully laugh

As some has mentioned it, word from our sponsors!

The MSc, which will start in September, is in "Drone Technology and Applications". And as well as full time mode it will be available in part-time mode of study - basically one day per week for two years. Obviously you would have to work outside that one day - but actual attendance is one day. The standard entry requirement is a 2.2 Honours degree in Engineering, Physics, Computer Science or similar. BUT,...there is a route to entry for people who do not have such a qualification but can demonstrate "substantial previous relevant experience".

Its proving very popular and we have a number of applicants already. As part of the course the students will build a DJI Flamewheel F550 or similar and use that for experiments during the course and the work for their Masters dissertation at the end. The reason for these little drones is simply to enable us to help these students get some flying experience in during the winter months when it might be difficult for them to fly outdoors.

BEB

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Posted by Biggles' Elder Brother - Moderator on 01/06/2015 12:16:49:

You'll find this a doddle Martyn! - I know that you have played with Arduinos before, on robots I believe. Very similar as you can see - I suppose in essence a drone is just a flying robot!

Good news you're going to have a go Richard - and I think this is a great potential way to interest youngsters in flying generally because the high level of computing content tends to appeal to them.

One thing I would stress to anyone thinking of having a go is that it is much harder to explain this stuff than is it to actually do it! Once you have the kit in front of you and get the software up on the computer everything makes a lot more sense and you can clearly see what you have to do.

BEB

I think you are doing a really excellent job of explaining this. C is not the easiest language in the world to learn - its also nowhere near the hardest either so don't get put off by that last statement! At least its not OO - something I never got to grips with.

I have actually had very little experience with Arduino boards although done quite a bit with C programming of Atmel processors through the AVR SDK development boards - its all basically the same principles though, just a marginally different IDE - I used the Atmel software.

This is a skill well worth learning, you will be amazed what you can achieve with very little exposure to or experience of these systems.

Martyn

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I found some useful cables on ebay, if you search for Dupont cable connectors of jumpers you should find something similar. Basically a short length if ribbon cable with single connectors at either end. At £1.65 each including postage I didn’t think it was worth making any up so, I got a female to male and a female to female.

dscf1530.jpg

I soldered on the pcb pins, the ones on the flight controller are a bit blobby but I got better when I got to the little I2C board.

dscf1523.jpg

Pity about the motor Chris. You wouldn’t mind if it was only 1 but when you have to get a set of 4 it adds up.

Nev

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I think I must have a thing about driver problems !
I installed the Ublox program and plugged in the GPS, laptop went off looking for the FT232 USB UART driver, I thought I had installed last time but it found it and eventually assigned COM4. So selected this in the test software and away it went, latitude, longitude and about 8 satellites, impressed or what.
After about 5 minutes though it stopped updating and a little error message appears Windows Ballpoint driver not properly installed ? Looking at the devices in control panel and it thinks my FTDI is a mouse and assigned the mouse driver Ballpoint to it.
So at the moment it's stopped working until I can figure out how to backtrack, maybe uninstall and try again.
How I love computers frown

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Well I turned it off and left it on its own so it could jolly well have a good think about all this playing up. (During which it probably installed everything properly) so now we are back up and running again.

Couldn't resist checking the coordinates from the GPS, it actually knows where I live.

How I love computers smiley

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The new motors turned up. Next day, on the very reasonable lowest postage option, so that's good service.

They look a real step up in quality.

I've mounted just one, this means opening two of the holes sideways but is no great problem.

A power test with the same props, shows 60W at about 6A as opposed to 45W with the original motor. I tell you what though, full revs seem an awful lot higher, there's quite a scream!

Props will sit a little higher, but I think it might even look a little better with the new motors.

img_4796.jpg

img_4800.jpg

img_4801.jpg

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