Robotics: Crenn's Third Year Project

[crenn]

As some of you may have heard from my talking in the chat, I'm currently trying to make a plane/helicopter twin bladed VTOL (think V22 Osprey) as my third year project.

Our group is made up of 4 people and we each have our specialisations. I'm in the process of designing the electronics and interfacing with everything in the project. We're planning to be using a Atmel ATMega640 running at 16MHz with a complement of servos, speed controllers and more.

Why am I suddenly making the post tonight? Because we caused a speed controller to burst into flames! How you say? The development board we're using has a voltage regulator dedicated for servos and it's meant to output 5.6v.... it was putting out 9v. We had been working with a normal servo most of time to get the signalling from the micro controller correct and decided to test with a speed controller (After we could control the servo fine) and that's when it popped and burst into flames.

Pictures to come tomorrow. Time for me to sleep.

EDIT: Temp links
http://www.scienceprog.com/avr-isp/
http://www.g.laroche.free.fr/english/hardware/ProgAVR.html

[crenn]

As promised, pictures:

http://i3.photobucket.com/albums/y81/crenn/th_IMAGE_009.jpg (http://s3.photobucket.com/albums/y81/crenn/?action=view&current=IMAGE_009.jpg)
http://i3.photobucket.com/albums/y81/crenn/th_IMAGE_010.jpg (http://s3.photobucket.com/albums/y81/crenn/?action=view&current=IMAGE_010.jpg)
http://i3.photobucket.com/albums/y81/crenn/th_IMAGE_011.jpg (http://s3.photobucket.com/albums/y81/crenn/?action=view&current=IMAGE_011.jpg)
http://i3.photobucket.com/albums/y81/crenn/th_IMAGE_012.jpg (http://s3.photobucket.com/albums/y81/crenn/?action=view&current=IMAGE_012.jpg)

[jdbnsn]

This project is going to be so cool, please keep us posted!

[x88x]

Heheh, I love the smell of burning silicon in the morning. XD

OOC, what was the reason for the 2-rotor design?

[crenn]

Because it looks cool and also because we can lift upto 1.5kg (3.3lb) which is enough for all of our equipment.

Updates will be a little more regular now.

[x88x]

Ok, fair enough. I was just wondering since from what I've heard the control systems for 2-rotor vehicles are a lot more finicky than for 1- or 4-rotor vehicles. How big is it gonna be to be able to lift 1.5kg?

[crenn]

About 30 inches or so across including the 11x9 blades.

[DaveW]

This is so sweet, I can't wait to see the finished product.

-Dave

[crenn]

Well, things are still happening, I'm currently designing the control board for the plane (and hoping I'm doing it right.) and hopefully I'll be etching it in a few days at the latest.

[crenn]

Here's a preview of what I've been upto:

http://i3.photobucket.com/albums/y81/crenn/th_ControlPCB.png (http://s3.photobucket.com/albums/y81/crenn/?action=view&current=ControlPCB.png)

Currently having a problem getting a copy printed out at a high enough resolution. The pads for the micro-controller have blended together, possibly due to the software not being able to print at a high enough resolution (printing at 600 dpi).

[DaveW]

What program did you use to design that circuit?

-Dave

[slaveofconvention]

Eagle 5.6 from cadsoft by the look of it - available as a lite version - freeware with limitations etc - download here - http://www.cadsoft.de/freeware.htm

[crenn]

Slave has it right! I don't know how I know the name, but I found it because I somehow knew and found they had a freeware version with limitations. So I've been using that ever since, good program too.

[crenn]

Here's a little bit of soldering that I did yesterday. We're going for a CPU socket type board so it makes things easier.

http://i3.photobucket.com/albums/y81/crenn/th_SV400144.jpg (http://s3.photobucket.com/albums/y81/crenn/SV400144.jpg)
http://i3.photobucket.com/albums/y81/crenn/th_SV400145.jpg (http://s3.photobucket.com/albums/y81/crenn/SV400145.jpg)
http://i3.photobucket.com/albums/y81/crenn/th_SV400146.jpg (http://s3.photobucket.com/albums/y81/crenn/SV400146.jpg)

[crenn]

After finally getting new speed controllers, we tested the fan on the motor.... They're AMAZING! Infact, when I didn't properly tighten the prop adapter, at about 50-60% power, it flew up and hit the ceiling (luckily noone was hurt because we got people to stay back and the prop was fine too) but once we tightened it all up, we had no problems and we got to 80% before we shut down the system). Pictures and Videos will come later in the week.

[crenn]

-_7pq68lKsw

Enjoy.

[Oneslowz28]

Looking good crenn. Keep up the good work.

[x88x]

Niiiice. Be fun to see it at 100% :D

[billygoat333]

you could probably cut down a small tree @ 100% lol

[crenn]

Considering those are glass filled nylon blades? I don't think we could cut down a tree.

[billygoat333]

lol it was an exaggeration. but it would be cool.

[crenn]

Update: MY BRAIN IS GOING TO BLOW.

More updates tomorrow.

[crenn]

_MRgZMmKGQc

Time to sleep now... Zzz....

[crenn]

Rough timeline for today

8AM Arrive at uni, goto soldering lab
9AM Start soldering
10AM Talk briefly with group member, continue soldering
11AM Still Soldering
12PM Goto shops to get lunch, forget to take a fork, eat a chocolate bar before going back to soldering
1PM Still Soldering
2PM Still Soldering
3PM Inform Group Members that I'm nearly finished before going back to Soldering
4PM Still Soldering
5PM Finish soldering the last few wires
6PM Wait to see if we can get a real programmer, find out we can't
7PM Try the DIY Parallel port programmer, encounter problems
8PM Finish doing presentation slides before leaving for home.

Guess what I'm doing tomorrow!

EDIT: Temp Links:

http://www.lancos.com/e2p/betterSTK200.gif
http://lcdproc.sourceforge.net/docs/stable-0-4-x-user-html/x904.html
http://www.nxp.com/acrobat_download/datasheets/74HC_HCT244_3.pdf

More links:

http://www.obdev.at/products/vusb/prjprog.html
http://www.lancos.com/siprogsch.html
http://www.simonqian.com/en/AVRminiProg/
http://www.fischl.de/usbasp/

[DaveW]

Keep up the good work man! Looking good!

-Dave

[crenn]

Amusingly, today is our last day we get to work on the robot. Majority of today is going to be spent writing the report which is due tomorrow. We'll be talking to the lecturer to see if the uni will allow us to continue working on this over the summer break.

Updates later today. And with any luck, more video too.

[crenn]

It's now around 2 AM and I only got home a couple of hours ago. But as promised, more video:

OqMW2TksxZY
Jkus9mbLmCI
RBoQ-xacsVg
FUfrl5vgdgE
SQYlejOFEL4
YN3wDgPSzRs

[x88x]

Nice. I thought it was a 2-motor design? Would I be correct in guessing the two unshrouded are for lift and turning, and the shrouded is for forward/backward movement?

Looks like you're almost ready for flight tests :D

What motors are you using for this? Also, is the end goal to have it computer-controlled, or stick with human?

[crenn]

The main propulsion is a 2 motor design, the ducted fan is just to stablise the system, it's not actually used for movement.

The motors are in the video descriptions. I'll post them here later. The end goal was to have the microcontroller get the system to hover the craft, however I was unable to get the microcontroller to work as I had designed. I'm still not quite sure what went wrong with it.

[DaveW]

That's looking really cool. It's a shame about the microcontrollers.

-Dave

[crenn]

Well the semi good news is we're allowed to take the project home, so I have something to work on over the holidays, I have 3 microcontrollers in a box, 2 ATMega640s and a ATMega32 which is planned to be turned into a USB programmer.

[crenn]

Well, this project isn't quite on hold, just split up, so what's happening currently?

Well, I'm playing around with an Arduino (finally able to test out the sensors and find out what is going on) currently and recently found out that I can hook this arduino in a certain way and use part of it as a programmer. I'm going to be also seriously thinking about redesigning the board and sending it to an etching company.

As for the mechanical side, currently that is being handled by the other main team member who is trying to find a R/C controller that can handle everything we need, the other problem is trying to control the speed controllers, but we need to organise a meeting for that, which is going to be difficult since the other team member is currently in an Industry Based Learning position for 6 months. We'll have to find some time eventually.

[crenn]

We'll today we managed to finally get the speed controllers working with an arduino after a little hassle. It turns out the normal servo library does a pulse every 20ms, which is great for a servo as it means the servo tries to hold it's position, but for a speed controller, it gives a pulse too often, so after a lot of trail and error plus a little research, we found we needed to give a pulse every 50 ms which means the servos are allowing a little drift, but it will correct every 50ms or so. To achieve this, we modified the Servo library included with the Arduino IDE to use 50ms instead of 20ms and we then found that when the speed controller's position was set to 0 degrees, it wouldn't respond, but it responded when it was set to 20 degrees, I've worked out how to fix this problem quite easily and it should also give me finer control over the motor speed.

A video will be uploaded later tonight.

[crenn]

ny1I4NXsAjM

Sorry it took some time to upload, but there it is. Questions are welcome.

[crenn]

THREAD REVIVAL!

This project has been taken onto my 'final' year project. While it's not my final year at the uni, the subject is usually referred as the final year project. We're hoping to get this thing to fly in a couple of weeks (this means serious time being put into the project, I did 9-6PM with a 30-45 lunch break today) and then adding more components and software modules until we have a full UAV.

Here's the result of the work today:

3x7gr2RLp4M

[SXRguyinMA]

sweet!

[crenn]

Want to see what 4 hours yields?

http://i3.photobucket.com/albums/y81/crenn/2011-03-23_16-40-49_810.jpg
http://i3.photobucket.com/albums/y81/crenn/2011-03-23_16-41-09_372.jpg
http://i3.photobucket.com/albums/y81/crenn/2011-03-23_16-42-23_773.jpg

It houses an XBee Wireless Communication Module, a dual axis IDG500 gyro and a triple axis ADXL345 accelerometer. The switches are used to switch the ADXL345 between SPI and I2C (my project partner wanted that ability). It's designed only to sit on my maple, but that's not an issue as we have another board that works with the Arduino, but doesn't work as a shield though.

Also to highlight the difference in processing power between the Arduino and Maple. Same function running on both, Maple took 56uS to do it, the Arduino took 1012uS to do the same function. Measured by making a pin high before the function, and low afterwards, measuring with an oscilloscope.

[SXRguyinMA]

nice! I've always wanted to mess with Xbee's. I will sooner or later :D

[crenn]

To quickly get started, I'd recommend a good guide... like this one!
http://forums.trossenrobotics.com/tutorials/how-to-diy-128/xbee-basics-3259/

But I'd also recommend this kit if you want to mess around with XBee Modules:
http://www.sparkfun.com/products/9897

The USB XBee Board will be priceless when you start!

[SXRguyinMA]

thanks!

[OvRiDe]

Nice.. finally got the Xbees! I can't wait to see the next video of an untethered UAV! :crossed:

[crenn]

Well, we haven't flown yet (due to various reasons) but I'd thought I'd give a little update to what has been happening. First off, we have a new mounting system for the motors and rear engine. They're less likely to suddenly come off in certain conditions. The new aluminium brackets were designed by my project partner:
http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-03-30_17-05-46_444.jpg
(http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-03-30_17-05-46_444.jpg)
Main Engines:
http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-03-30_17-06-07_225.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-03-30_17-06-07_225.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-03-30_17-05-56_992.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-03-30_17-05-56_992.jpg)
Rear Assembly:
http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-03-30_17-06-38_507.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-03-30_17-06-38_507.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-03-30_17-06-24_337.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-03-30_17-06-24_337.jpg)

There also has been a couple of changes to the electronics, we now have a Razer IMU on a new daughter board, we also removed the switches so the ADXL is connected exclusively on I2C.

http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-04-04_15-55-07_378.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-04-04_15-55-07_378.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-04-04_15-54-58_514.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-04-04_15-54-58_514.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-04-04_15-56-42_380.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-04-04_15-56-42_380.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-04-04_15-56-24_624.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-04-04_15-56-24_624.jpg)
http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-04-04_15-55-33_358.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-04-04_15-55-33_358.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-04-04_15-54-52_256.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-04-04_15-54-52_256.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/th_2011-04-04_15-54-34_234.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/?action=view&current=2011-04-04_15-54-34_234.jpg)

The rest of the work has been done in software, and the first thing done is rewritten the Razer firmware to output raw data at 500Hz (compared with calculated data at 50Hz) and get the Maple to process the data (does the calculations is 700uS at most) before outputting the data that the Razer normally outputs, over the XBee module (although it only outputs once every 18 calculations) to the computer where the Razer's program shows the orientation.

The reason why we're doing the processing on the Maple? The Maple is a lot faster at doing it, and once I switched to fixed point calculations, it will be even faster. I can do the calculations on the Razer (8MHz ATMEGA328 running the arduino bootloader), but they are slower.

Additionally tests have been run using the Maple's hardware I2C to control a motor. We had some problems, but they may be to do with the Wire Library I've written. However, after working around a small problem, the motors can be controlled without issue. Potentially, we could have an actual flying test next week, however, that's dependant on the progress on the control system.

[SXRguyinMA]

looking good! I can't wait to see it fly :D

[crenn]

Neither can we! It's been almost 2 years since we've started this project, and we haven't gotten off the ground yet!

[Crimson13]

What's the weight like so far? I think my big time/wallet killer this summer will be a quadcopter.

[crenn]

1.5-1.6kg (3.3-3.52lb). I wish I had the money to buy up some hobby stuff like an RC Helicopter kit.

[SXRguyinMA]

you can find them cheap! take a look at the E-Flite Blade mCX. I had their older CP (which getting a CP heli for a NOOB was a BAD idea lol) then I got their CX and had a blast with that, till I traded it and a tool cart for the pair of 3870x2s I had lol

[x88x]

1.5-1.6kg (3.3-3.52lb). I wish I had the money to buy up some hobby stuff like an RC Helicopter kit.

Check out hobbyking.com if you haven't already. Not always the best quality stuff, but there's good stuff in there if you're careful...and the prices are dirt cheap...

[SXRguyinMA]

microquadrocopterzzzz!!!

http://hackaday.com/2011/04/29/mini-quadrocopter-is-crazy-awesome/

[crenn]

you can find them cheap! take a look at the E-Flite Blade mCX. I had their older CP (which getting a CP heli for a NOOB was a BAD idea lol) then I got their CX and had a blast with that, till I traded it and a tool cart for the pair of 3870x2s I had lol

I'm wanting a full feldged Collective Pitch helicopter for research and to learn how a 'real' helicopter works!


Check out hobbyking.com if you haven't already. Not always the best quality stuff, but there's good stuff in there if you're careful...and the prices are dirt cheap...
HobbyKing is actually where a few out our parts come from (RC TX/RX, LiPo and LiPo charger), so we know very much about it. Prices for individual components might be near dirt cheap.... but, this is the kit I was looking at:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10444

However, when you're a student with only a fist full of dollars left, can't really stretch things to get it and the parts needed.


microquadrocopterzzzz!!!

http://hackaday.com/2011/04/29/mini-quadrocopter-is-crazy-awesome/

Very interesting, I wish they used brushless engines though!

[SXRguyinMA]

I'm wanting a full feldged Collective Pitch helicopter for research and to learn how a 'real' helicopter works!

http://www.bladehelis.com/Products/Default.aspx?ProdId=BLH3500

the cheapest CP heli I found

:EDIT: cheaper as a BNF

http://www.bladehelis.com/Products/Default.aspx?ProdId=BLH3580

[x88x]

Fair enough...I remember being in that position as a student. The one time you have the time to work on lots of cool projects and access to lots of cool equipment to achieve those projects...and no money to buy the parts required for those projects.. :(

I'm guessing that the microquads went with brushed motors to simplify the motor control circuitry. Brushless motors are awesome, but they do require more components in the controller. :( One thing I would change about their design is, ironically, one of the main things they were trying to achieve..that is, making the PCB the entire structure. With a PCB that shape, the PCB manufacturing costs would skyrocket because of all the wasted space. Much better, imo, to use tiny CF struts that are bolted or, better, epoxied to the PCB.

[crenn]

Fair enough...I remember being in that position as a student. The one time you have the time to work on lots of cool projects and access to lots of cool equipment to achieve those projects...and no money to buy the parts required for those projects.. :(

I'm guessing that the microquads went with brushed motors to simplify the motor control circuitry. Brushless motors are awesome, but they do require more components in the controller. :( One thing I would change about their design is, ironically, one of the main things they were trying to achieve..that is, making the PCB the entire structure. With a PCB that shape, the PCB manufacturing costs would skyrocket because of all the wasted space. Much better, imo, to use tiny CF struts that are bolted or, better, epoxied to the PCB.
Well, I'd have money if I can find a job, and the last job I had, they complained I was too slow preparing/painting. They paid me for the work that day, and told me they'd call me back if they wanted me again (as I suspected, they haven't called back).

Brushed motors are simple, but they have an efficiency problem, but they're not too bad to control. They do need 6 transistors per motor though. Well, the problem with using CF struts is you need to have wires still for the motors, while the PCB design, they're using the arms as the conducting path. But they haven't necessarily wasted that PCB space, they might have done other little boards when they got that PCB made up.


http://www.bladehelis.com/Products/Default.aspx?ProdId=BLH3500

the cheapest CP heli I found

:EDIT: cheaper as a BNF

http://www.bladehelis.com/Products/Default.aspx?ProdId=BLH3580

Cheaper as a BNF because you need a transmitter. I'm trying to find out where I can get these and if they ship to Australia.

[x88x]

Well, the problem with using CF struts is you need to have wires still for the motors, while the PCB design, they're using the arms as the conducting path. But they haven't necessarily wasted that PCB space, they might have done other little boards when they got that PCB made up.

True, true. I was thinking along the lines of producing a bunch of these, and only these. I guess if you could fill in all the empty space, or use a service that does, it could balance out.

[crenn]

Well, I looked into the helicopters that SXRguyinMA linked to, and found I can only get the BNF kit, however, the problem is then the transmitter, the transmitters I found cost more than the helicopter! However, I found a kit on hobby king, and I costed it:

Parts selected:
-Micro Helicopter-
Fire Fox EP100 Micro 3D Helicopter w/ Motor only (KIT ONLY)
HobbyKing 12A BlueSeries Brushless Speed Controller
ZIPPY Flightmax 800mAh 2S1P 20C
Hobby King S0361 3.6g / .45kg / .12sec Micro Servo
HobbyKing GA-250 MINI-MEMS Gyro
-Transmitter and Chargers-
Hobby King 2.4Ghz 6Ch Tx & Rx V2 (Mode 2)
Hobby King 2.4Ghz 6Ch Tx USB Cable for Win2000/XP
AA 600mAH Ni-MH Battery Set (8pc)
HobbyKing Variable 6S 50W 5A Balancer/Charger w/ accessories

Total cost in USD: $112.01 (excluding shipping)

I might look at getting that little helicopter first before I move up to something bigger!

Links to the parts:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9387
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11429
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6786
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=3715
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15318
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9042
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9043
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16386
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11668

[Fuganater]

I was just looking at HobbyKing for random things. Their shipping is ridiculous. $17 cart and it cost $30 to ship it... I deleted my cart.

[crenn]

Heh, it depends on how you ship it, the micro helicopter I priced before is now $140.75 with shipping. It costs 28.74 for a 2.1kg package. That's fairly reasonable I think.

[x88x]

I was just looking at HobbyKing for random things. Their shipping is ridiculous. $17 cart and it cost $30 to ship it... I deleted my cart.

They have four warehouses throughout the world. The main one in Hong Kong, and regional ones in Germany, Australia, and the US. If you live in an area that has a regional warehouse, it's almost always much cheaper and faster to order from that regional warehouse, but if not, always order from the Hong Kong warehouse (ie, I would never order from the Germany warehouse, for example). There are a few oddities, though. For example; you would think that if you lived in Canada, ordering from the US warehouse would be best, yeah? Not necessarily. IDK about other stuff, but I know at least for batteries, orders going to Canada from the US warehouse take as long if not longer than orders coming from the Hong Kong warehouse. *shrugs* TBH though, the shipping costs from their Hong Kong warehouse are actually quite reasonable, considering.

[crenn]

No updates for this project, but I've planned out my future one on my site:
http://crennsmind.com/index.php/future-projects/71-micro-copter

Just need to get funds to do it...

[crenn]

I haven't updated for a while because the workload has been heavy, although things have been easing off lately. Although, I do have an exam today, even though I have an exam today, this is what I was upto yesterday afternoon:

http://i3.photobucket.com/albums/y81/crenn/Projects/Maple_Mini/th_2011-06-07_16-19-05_76.jpg (http://s3.photobucket.com/albums/y81/crenn/Projects/Maple_Mini/2011-06-07_16-19-05_76.jpg) | http://i3.photobucket.com/albums/y81/crenn/Projects/Maple_Mini/th_2011-06-07_16-18-03_65.jpg (http://s3.photobucket.com/albums/y81/crenn/Projects/Maple_Mini/2011-06-07_16-18-03_65.jpg)

[crenn]

No updates for a while, but stuff has been happening:

RhDwPY917PI

I've been working on interfacing the RC receiver to the Maple Mini via 6 pins. I'm going to be using interrupts triggered by timer input captures, but initially I'll be using external interrupts. I've had pointed out this morning that I can have a single pin for all 6 channels by doing a logical OR. This means that I free up 5 pins and also 3 PWM channels, allowing all of the measurements to be done with a single PWM channel or external interrupt.

[SXRguyinMA]

I don't understand too much of that but progress and freeing up pins are both good :D

[crenn]

SXRguyinMA, the RC receiver channels output a PWM signal with a pulse of a length between 1100uS and 1900uS every 22ms which usually a servo uses to determine the position it should be facing. In this case, I want the microcontroller to measure this so we can use the RC RXTX to control the robot. The new method saves on pins because of how the channel signals are structured and because there is a gap between each pulse, meaning I can still tell which pulse comes from which channel.

[SXRguyinMA]

ahhh that makes more sense lol

[crenn]

I'll leave these here ;D You can see the 4072 IC (Dual Quad input OR gates) that I used for the RC Receiver.

http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/th_DSC_0005.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/DSC_0005.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/th_DSC_0003.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/DSC_0003.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/th_DSC_0001.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/DSC_0001.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/th_2011-08-19_22-06-17_222.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/2011-08-19_22-06-17_222.jpg)
http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/th_2011-08-19_22-06-07_802.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/2011-08-19_22-06-07_802.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/th_2011-08-19_22-05-38_725.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/2011-08-19_22-05-38_725.jpg) | http://i3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/th_2011-08-19_22-05-15_307.jpg (http://s3.photobucket.com/albums/y81/crenn/TBVTOL_Project/PCBv01/2011-08-19_22-05-15_307.jpg)

[SXRguyinMA]

nice! how do you go about perfectly aligning the 2 sides? I'm going to be making a double-sided board (or two) and want to know what the best way is :D

[crenn]

I'm not sure how my uni does it, but I believe they align the tool to a couple of the holes.

[billygoat333]

I'm not sure how my uni does it, but I believe they align the tool to a couple of the holes.

That's what she said.

[crenn]

ruEvBooHrMo

After an eventful past week, we're ready to do some flight tests some time next week providing everything continues to work correctly. Last saturday we were preparing to start doing more tuning of the control systems and looking at doing flight tests, however errors occurring while I was touching the frame, the errors were found to be a result of some bad solder joints and before any flight tests could be done, they needed to be fixed.
Just before the public was allowed to come into the room during the open day, I touched up several solder joints and went to go test the board, I plugged it in to test and found the board no longer powered up. While trying to find the fault, I accidentally caused a short circuit through the frame while connected to the battery which I thought has killed the voltage regulators on the board meaning we couldn't display the robot working during Open day, but we got plenty of questions about it regardless.
The very next day, I started to work out what had happened. A bad solder joint was the cause of the problems on open day, not the voltage regulators at all, even more amazing was the board was completely fine after fixing that one solder joint! But it had already been decided that we needed a spare board in the event of a board failure and I also designed a standard testing procedure for testing the circuit boards before they go into use or after a repair/modification. Pretty much it's just verifying the board is working, with a bench power supply, which will shut itself off if a short circuit occurs.
3 days ago, I got the new circuit board made, and spent the next day assembling the board after classes, getting a parcel through the uni (containing the plane for a personal project, SEPA) and sorting out trying to get a refund for a faulty battery which cannot be returned because of it's poor condition. The faulty battery was meant to be a spare battery for our project, but sadly that's not to be.
Today I verified both microcontroller boards for use with our project and integrated the sensor which allows us to monitor the voltage level of the battery and also the current that an engine is drawing. My associate worked on a testing harness so we can do tethered flight next week. I promise to upload photos tomorrow, SEPA and MEHA will also have some photos taken of them and I'll detail more stuff tomorrow as well. More site content is coming as well, I haven't had the time to even look at updating my site until now!

[SXRguyinMA]

glad it wasn't anything major :D

[crenn]

Me too! It would have meant a major redesign of the boards, I'll try to upload some pictures later today.

[crenn]

Well, I should probably update.

Last Friday we attempted a flight test.... in summary, it was dangerous and we didn't prepare enough as we should. But the main thing is, we're uninjured and it's not likely to happen again because of changes to happen. I'm currently pondering whether I should release the footage of the tests, or at least crop it to avoid some of the words said during it.

[SXRguyinMA]

is the machine ok?

[crenn]

There is slight damage to to propellers, but I think they should be replaced anyway.

[crenn]

Well, this project is winding up. Basically the summary of what the end result of the project will be, is that it was starting to get stable, but no where near enough needed to start hovering. I'm disappointed that the result is like this, however, there has been a lot of unexpected problems during the project which meant progress stalled or even went backwards (especially when an IMU seemed to stop working correctly). We're further than we were at the start of the year, just the progress has been very disappointing. We were expecting to be able to hover in the middle of the year, and when a test was performed to attempt to fly, it highlighted a dangerous disregard for safety.
Today one of the recommendations I made several weeks ago to prevent one of the problems occurring accidentally, was finally implemented. It took 5-10 minutes to implement and another 10-15 minutes to remove some unintended bugs (which made it harder to cause an accident, but not the behaviour desired). When I think about it, that really annoys me.

[SXRguyinMA]

Sorry to hear man. I'm glad you at least made some kind of forward progess at least! I'm still looking forward to the outcomes of MEHA and SEPA :D

[crenn]

While forward progress is nice, it would have been better to get it at least hovering. But frankly, after the accident, I don't want to be near it when doing a flight test. Even one of the props fell off last night (they weren't tightened enough for some reason).
MEHA and SEPA should be getting an update tonight, I have parts waiting at the post office, the major airline here grounded itself for 2 days causing chaos which meant that was delayed.

[crenn]

Well, the report and presentation is done which marks the end of my involvement to the project. I'll be posting up a series of posts on my website starting Friday next week. This will attempt to go into detail the reason why the project wasn't successful and some of the things that happened. I'll post in here when I upload something.