Paparazzi news!

[AntonK]

For those who have always wondered how good IR sensors could be for attitude sensing should take a look at the News on the Paparazzi wiki page. Here:

http://paparazzi.enac.fr/wiki/index.php/Main_Page

A short excerpt:

"They took off and landed on the helicopter deck of the Norwegian icebreaking coast guard vessel KV Svalbard for one week and set a new Paparazzi low temperature record by flying at around -20°C and 15m/s wind in altitudes up to 1500m. For another two weeks they also collected data on Spitsbergen near Longyearbyen. "

AntonK

[Jack Crossfire]

They need to photograph Sissel from a UAV.

[zlite]

There's a new interview with Martin Mueller, one of the Paparazzi team leaders, on DIYDrones here (http://diydrones.com/profiles/blog/show?id=705844%3ABlogPost%3A29982). He discusses the IR (thermopile) sensor performance in bad weather and the new availability of pre-built hardware.

[dmgoedde]

Ditto.

I have been trying to tell people how good thermopiles are!!! See?!? Ever wonder why the ezi-nav $2800 system uses them? Why Paparrazi and Attopilot uses them? They are far more than toys, no matter what a certain person at a certain WA-based autopilot LLC might say.

I was doing an autonomous flight the other night with AttoPilot which has barometric altitude control with thermopiles as a key part of the pitch control, watching the real-time down-link on my laptop, and the alt-hold was +/- 0.3 meters. No joke. Thermopiles are fabulous 95% of the time, for 95% of the flying requirements.

Dean

[air]

Anton, does Paparazzi use GPS altitude alone for altitude hold?
What kind of accuracy does this achieve? Is there any smoothing used on the (sometimes erratic) incoming GPS z-axis data?

[AntonK]

Yes, Paparazzi uses only GPS altitude for its hold. There is a small bit of Kalman filtering that compares the change at 4Hz and also the z velocity to smooth things out a bit. In flight testing this filter has worked very well.

Anton

[air]

Cool thanks for that.
I'm about to order everything from ppuaz.com to start experimenting, I'm keen to find out how it performs vs the other products on the market that I've tried.

Final question - have you any source for the dreaded molex crimper in Europe?
When i'm shelling out the $200 it would be nice if it was available with a kit of connectors so that I could use it for other applications.
Farnell sells it here for 369 Euro!!! :eek:

[AntonK]

These plugs are really the downfall of the hw design. However they are very small! The Europeans I know all got their crimpers from Digikey. If you dont want to shell out that cash you can get precrimped wires from Radiospares I think. The wire isnt the greatest, but it would get you going first off. Ill talk to ppuav about possibly offering some wiring solutions( kit type ).

Anton

[air]

Hi Anton,
Yes, it's a shame it doesnt have standard headers for the primary servos at least, although the molex ones would be fine only for the price of the crimper - they're nice and secure.

In the meantime I've bought lots of pre crimped cables from farnell as well as the sockets to go with them (including some cables with sockets at both ends for connecting to the Molex connectors on the IR modules)
These should get me going with the pre-assembled board I'm ordereing from ppuaz - can't wait to get it up and running.

[AntonK]

The very first boards used standard servo connectors. However the first users of this system were building MAVs that were 12 inches in wingspan. We tried to save grams where ever we could. I think having a larger version down the road with standard connectors would be cool. Better yet maybe a Servo interface board with external power similar to the Micropilot might be a good option for larger airframes.

Anton

[air]

Yes I can see how it made sense for the MAV competition models.
Still it wouldnt really cause any problems if there were pre-made breakout cables readily and cheaply available.
An external servo interface board would be cool too, with optically isolated servo channel connections and external power it would help protect the main uC from some noise & current draw too.

[bmw330i]

I wrestled with the IR solution mentally for a while until researching the alternative (IMU). I decided to get in the air fast IR is the best. Now my expectation is I will find this is all I need. I am sure IMU can be added as well to supplement the IR...Paparazzi is Open Source...it's going to take time before people realize all that code is right there for you to "enhance" as you need. Just follow the GPL and everyone should be happy.

Back to the Need for expensive crimpers...and IMHO...The issue(s) with the Molex.

I bought the crimpers. They work great. However, to be honest with our FunJet I'm going to de-solder the 3-pin Molex connectors at the PCB and solder servo Female connectors in their place. Reason being how crappy typical 26gauge stranded wire is. Makes Servo wire look like magic flexi wire by comparison.

For now really I'd say if you are not building a 12" wingspan MAV servo wire with a servo extension wired to the PCB on the assembly seems like a good way to go...PPZUAV can do that... they already load the boot code into the CPU for customers before shipping (saves you having to buy an FTDI cable and adapter you'll use only 1x). So doing that isn't a big deal.

Just remember PPZUAV is NOT TowerHobbies. They are using (i.e. building Paparazzi projects) it like everyone else so custom stuff, or asking for something not listed is no big deal. If they don't know they will tell you who or where to look.

What continues to impress me with Paparazzi, is the access everyone has to the people who designed it, who maintain it, who use it in real projects. Not just 1 guy who has a day job already. Who has the best intentions but is still just one guy and going to be busy most of the time...Paparazzi is many many people who combined are providing 7/24 support via the above avenues (email, IRC, Mail List...and PPZUAV)...

Linux was the same way in the start and look at it now. The support is there for Paparazzi. Just my experience. I mean I started from knowing nothing and thanks to that support...know a lot more than I did. Long ways to go but I can rest assured the support is there.

[AntonK]

Good write up bmw330i. I think the funniest question I get from people is "can paparazzi do this" I always answer "It can do whatever you ask of it." Want an IMU, go for it. Now of course that doesnt mean you will get an attitude solution :) but you can have an IMU! What is great is you have an autopilot that will pretty much fly a plane without too much work. It will RTB in the case of lost link, and has a very dynamic HMI interface that allows for a lot of different options. But most importantly its open. You can change the source as you see fit. I mean I started with the standard paparazzi code, and now I have an attitude stabilized quadrotor, simply because I took the time to know the code, and started writing.

Anton

[magnetman]

Hi BMW,

I'm running a Dragon OSD which is fine, but development appears to have ceased as as far as sensor integration goes. Can the Papparazi kit be purchsed in kit form??, or do you have a parts list already made up??
I'm quite happy to go through the learning process.

Also, this way I don't have to use Molex, replace those with pin strips as per Dragon OSD fashion!

Thanks

Magnetman