Picopilot Question

[icebear]

I am testing the PICOPILOT and have a few questions if anyone has experience with this unit...

I have connected the PICOPILOT to a GPS, receiver, an aileron servo, a 6 v voltage regulator (from the electric power pack) and my PC.

However - the Waypoint editor refuses to accept waypoints wheh I enter them. The waypoints are read-back from the Picopilot so this indicates that the communication (COM1 serial port) with the PC doesn't work.

Everything else seems in order - the GPS LED flashes, the NAV STAT indicator flashes red indicating it is awaiting sattelite data from the GPS and there is a green light from the ALT STAT LED indicating this unit is OK.

Grateful for any comments from someone who has experience with this unit!

Regards,

Icebear

[icebear]

OK - I found the problem - the Tx/Rx wires to my PC had to be reversed and that solved the problem! (my RS232 was not a 'null-modem')
Updates on project will be posted here soon...

/Icebear

[cmoulder]

I am testing the PICOPILOT and have a few questions if anyone has experience with this unit...

I have connected the PICOPILOT to a GPS, receiver, an aileron servo, a 6 v voltage regulator (from the electric power pack) and my PC.

However - the Waypoint editor refuses to accept waypoints wheh I enter them. The waypoints are read-back from the Picopilot so this indicates that the communication (COM1 serial port) with the PC doesn't work.

Everything else seems in order - the GPS LED flashes, the NAV STAT indicator flashes red indicating it is awaiting sattelite data from the GPS and there is a green light from the ALT STAT LED indicating this unit is OK.

Grateful for any comments from someone who has experience with this unit!

Regards,

Icebear

Icebear, I just got a Picopilot NAT and am going through all the manuals.

The main manual indicates the use of the serial port as Com1, but none of the laptop computers I have found have got any serial portsl, only USB.

Do you know if a USB to serial adapter will work in this instance?

Are there any other critical specifications I should know about when buying a laptop computer for this system?

Thanks for your advice.

-- Bob

[icebear]

Hi Bob,

Congrats to getting the Pico NAT! :D

I still use my old PC for the Picopilot Editor, but I recently got at new laptop with USB only so I purchased a RS232/USB converter cable.
I believe you can change in the editor menu so that you use Com8 or whatever gets assigned to your standard USB/Serial converter.

I have got the converter but haven't tried it yet. The Editor will post an error message if it doesn't find the right Com port, but you should still be able to get in the menu and change it.

Let me know what you find and I'll see if I can get mine to work tonight!

/Icebear

[cmoulder]

Thank you very much, Icebear.

I have ordered this adapter cable and hopefully it will work. It seems that these days not even the most expensive laptops have a serial port.

I am also shopping for a laptop and am hoping that a comparatively inexpensive one will be adequate for the Picopilot and also for a video downlink. I have gotten the Diversity system from Future Hobbies and hope to eventually integrate all this into a Sr Telemaster platform.

Obviously, I am new to all this, so I have many questions, and more every time I turn the page!

-- Bob

[icebear]

I think any laptop would work just fine - I would recommend staying with XP and not go for Vista yet.

You'll find that several people here have integrated the Picopilot in a Telmaster - check out the thread by workshop - very informative and useful on his findings.

Keep us posted on your progress :)!

Bjorn

[cmoulder]

Hmm... all of the laptops sold here now have Vista installed, so I it looks as if I will just have to deal with the bugs for a while. I think I am going to get it at a chain store called Best Buy and perhaps I can get them to downgrade it to XP at no charge.

Generally speaking, however, I know not to get the latest version of Windows until it has been out for a year or more.

Yes, I have read the entire Catalina Island Project thread about 3 times and have started with the Flying Boat. You guys are amazing!!! :D :D And I plan to use the Telemaster Electro with the pod-mounted motor as my learning platform.

My goals are much more modest. I plan to remain entirely line-of-sight, using the Picopilot to help loiter at a specific waypoint and (low) altitude, so I can do some hi-res still photography. I will not be flying out-of-sight for a good while yet, until I learn a lot more about how the systems work, how to integrate them, and about the regulations involved. I used to be a professional photographer so at present that is the only aspect of the project that I understand thoroughly, and I consider myself a pretty good RC pilot and constructor.

Not so sure I will start a thread because there is absolutely nothing I can offer at this stage -- I am purely a student. But I will pop in here to ask questions and to update.

Thanks again, Bjorn, for your help and your interest.

-- Bob

[zlite]

Not so sure I will start a thread because there is absolutely nothing I can offer at this stage -- I am purely a student.

Welcome! You might also want to check out our community at DIYDrones.com (http://diydrones.com/), which is really oriented for beginners. We try to keep all our UAV projects under $1,000 and within the reach of a smart high school student. (Fortunately, some of them are really smart!)

[cmoulder]

Thanks zlite for the welcome and the link!

I don't have an electronics background so I am trying to put together a decent package of off-the-shelf components. In the current state-of-the-art that appears to be possible now, so it won't be all that cheap but also not prohibitively expensive. Since I'm staying line-of-sight for the foreseeable future, the package will be a lot simpler than if I required tracking and remote telemetry.

Got to get the wing and motor pod put together first, so I started sketching the design and planning other modifications to the plane as I wait on other components to arrive. Already is extremely interesting and satisfying.

-- Bob

[icebear]

Bob,

You mentioned the Catalina Island project when I referred to Workshop. I was actually thinking of his previous thread "Picopilot and Sr Telemaster" where there are lots of info on setup and fine tuning. You could practically setup your control throws etc. after his recommendations there on the Sr. and go flying, I think!
I have used the OMNI Veetail mixer as Jeff suggests and it works great to create coordinated turns in an aileron setup (Picopilot turning using ailerons with a little rudder mixed in). And don't forget check out my 'Lighthouse mission' in this forum too if you haven't seen it :)

/Bjorn

[air]

I used the NAT with a USB to Serial adapter without problems once I used an adapter to swap the wires as Icebear did.
Your mileage may vary though because some of the USB/232 adapters dont follow the RS232 spec fully.

However I suspect that my adapter is pretty crap (it didnt work with a certain revision of a Garmin GPS for example) and it still worked fine with the PicoPilot so you should be ok.

[cmoulder]

Thanks for those suggestions as well, Bjorn.

Wow, that lighthouse mission took some nerve! I'll bet you were quite relieved to see your model come back into view at the end of the mission!!!

As for the coordinated turns, just so I don't have to buy another device I am hoping to be able to set up the servos (and trim the linkages and throws mechanically) so that the Pico can do it. I know this is going to be a tedious process, and I am going to have to do a lot of test flights to see how much rudder will be required. I am developing "clevis finger" just thinking about it. :o The Picopilot manual mentions adverse yaw often enough to suggest it is a particular problem.

At this point, I don't plan to be doing anything with the Tele Sr for a while, and the longer-range plan with that one is to put a small gasoline engine on it with a large enough fuel tank (and batteries) to keep it airborne for about an hour. Ambitious, yes, but I am taking the long view and willing to take the "baby steps" at this point. In fact, with such an endeavor there is no other way to proceed.

-- Bob

[cmoulder]

air, I have a couple of different USB/serial cables, so maybe one of them will work. If not, I will look for those posts about the modification.

BTW, I have the old Mapsource topo sets with the 1:100,000 maps... will those be adequate for plotting and uploading waypoints??

-- Bob

[air]

I'd be pretty certain that any of your adapters should work once you have the correct drivers installed and have verified that it works with another device - double check on crossing the tx/rx lines too though!

I dont know about Mapsource, I used OziExplorer which lets you scan in and calibrate your own maps. I also used it for a realtime moving map display with a MaxStream Xbee & it worked really well for that.
I
I wrote a php script to convert PHP files from the OziExplorer waypoint file format to the PicoPilot file format, however I unfortunately lost it in a reinstall.
I'll probably rewrite it if i cant get my hands on an Attopilot before the start of the season :)

[cmoulder]

air, you're way ahead of me, so I'll just have to plug-n-play for now and see if it works.

Yikes, I just read in the Sr Tele thread about the Futaba PCM voltage issue, so there's another problem to deal with and I haven't even started yet! Printed out the short thread on RCAPA dealing with the fix...

-- Bob

[air]

I read that my receiver (Multiplex DS IPD) had that problem with the signal levels as well & purchased 4 buffers from FMA.
It turned out it worked perfectly directly connected (should have checked first).
I can sell you the buffers at 20% below cost if you want them, I never took them out of the pack - they're the model recommended by U-NAV.

I'm not that far ahead either, it's really pretty quick once you have it physically installed. Just upload your waypoints, launch, flick it to auto & see how your gains are working out.

I'd recommend having a go with it straight away in fact, let it acquire sat lock and launch. You can check out how it's performing as it circles your location.

[icebear]

Bob,
Yes, seeing the plane come back from sea was a great relief! :)
That's my only 'sea' mission so far!...

Like air suggest, I think it is a good idea to start with no WP's loaded and just let it go on auto after achieveing GPS lock and take-off to safe height and see how it repsonds to the automatic 'return-home'.

You don't need the OMNI mixer if you Y-cable rudder and ailerons and set the mechanical control throws to what for example workshop found to a good start.

Adverse yaw should not be much of a problem since you are using both rudder and aileron to create coordinated turns.

/Bjorn

[cmoulder]

air, thanks for the WP suggestion, and as far as the receiver I have a PPM and have ordered the H9 failsafe as a less expensive solution in the meantime. I plan to progress slowly and keep the plane in quite close at first and gradually expand the range. And my finger will never be far from the "enable" switch. ;)

Bjorn, I have read some posts mentioning that the rudder was enlarged for these models, but my experience is that coordinated turns don't require a lot of rudder, so I am wondering if this is in fact necessary.

-- Bob

[icebear]

Bob,
I don't think you would need to increase rudder at all. I did in fact decrease mine in my Viking setup (similar in shape to a TM). The Picopilot is quite sensitive so I would go with minimum throw for both ail and rud and start off on a low level gain (say 30 percent) and increase if you are not happy.
Check out how much ail+rud travel workshop used in his telemaster sr as a starting point.
Good luck,
Bjorn

[cmoulder]

Very well. Reading through the threads I got that impression. I am fairly certain that with the wing dihedral of both these models they could be flown quite nicely with rudder only and turn well. Rudder only looks a bit sloppy with too much rudder applied too quickly, but it seems the Picopilot "prefers" gentle turns. At least there's no adverse yaw with rudder only turns.

Here are some pics of my first day's work, showing the motor pod and the pylon, borrowing workshop's (Jeff's) idea of using a "stump" in the wing to attach the pylon. Since Jeff already figured out the thrust angle pretty well, I just built it in, with 4 deg up, and I added 2.5 deg right. These can be tweaked, of course, with washers behind the radial motor mount.

[cmoulder]

RFI concerns

In the Picopilot documentation, it states that RF filters should be used on the servos, so I am anticipating using ferrite rings, but am wondering if the FMA servo buffers (which are needed for PCM receivers anyway) offer enough RFI filtering by themselves.

I have copper foil to make the electronic component modular boxes (a-la-workshop's tele electro), as well as the Smart-Fly linear regulators for receiver and GPS. I am wondering, will this will provide adequate RFI protection if I use a 1w 2.4 ghz video downlink? I noticed in one photo of workshop's Tele Electro that there appeared to be a copper foil "RF splashboard" on the bottom of the model where the video tx antenna exited. Am I nuts to use a 1w downlink when the transmission distances are going to be no more than 1 mile for the foreseeable future?

Since I plan to use a separate receiver battery, I plan to disconnect the red power wire between the ESC and receiver. I am using the standard Jeti 70-amp ESC (not the Opto). Should I use an Opto ESC to reduce noise, or a ferrite ring, or is the RFI negligible with the ESC's red wire disconnected?

TIA for sharing your expertise and experience.

-- Bob

[air]

Hi Bob, I never did anything to protect against RFI and I had not problems.
Yes you're nuts with that 1W transmitter for 1 mile range ;)
I think Kilrah over on the FPV forum gets almost 2Km with a 10mW transmitter - yes 100 times less power than you're proposing.
If you use appropriate directional antennas that are correctly polarised at each end I think 200mW should be more than enough for you.
Having said that if you have loads of physical space for a gap between the video TX and the rx & lots of spare payload capacity then I'd say go for it!

[cmoulder]

Hi Bob, I never did anything to protect against RFI and I had not problems.
Yes you're nuts with that 1W transmitter for 1 mile range ;)
I think Kilrah over on the FPV forum gets almost 2Km with a 10mW transmitter - yes 100 times less power than you're proposing.
If you use appropriate directional antennas that are correctly polarised at each end I think 200mW should be more than enough for you.
Having said that if you have loads of physical space for a gap between the video TX and the rx & lots of spare payload capacity then I'd say go for it!

Okay, I think at this point I'll just continue to assemble what I've got (already had a 200mw tx on the way anyway...) and then expect that I've taken enough measures until extensive ground and air checks reveal no glitching. I'm probably being excessively concerned, but this my first time with so much rather expensive gizmology aloft... :o

-- Bob

[cmoulder]

Pico throttle questions

I have all the control surfaces set up manually with zero trims, zero expo, no servo reverse, etc, and everything is moving in the proper direction while being controlled in the MAN mode of Picopilot.

However, the throttle stick is reversed and there is no way to reverse it with the Picopilot, as far as I can tell so far. The Picopilot jumpers are used to reverse the direction of the throttle response in relation to the pressure sensor changes. At this point I am assuming that it is okay to use the R/C TX to adjust the direction and endpoints of the throttle (ESC) and then use the Picopilot jumpers and gain to fine-tune it when Picopilot is enabled.

Does this sound correct??? :confused:

[cmoulder]

Okay, it took a couple of days of persistence and pulling out what little hair I have left :mad: , but I figured out how to get Picopilot to work with Windows Vista. :D :D

Here's what works:

In Windows Vista, right click on the PicoPilot icon, click "properties", tab for "compatibility" and then select Windows 2000, then apply.

I installed an iogear RS232-to-USB adapter with iogear driver software. It works without a null modem adapter, and will not work with a null modem adapter.

Go into Control Panel, then Hardware, then Devices, then Ports then the iogear adapter (ATEN) then Port Settings, then Advanced, and uncheck "Use FIFO buffers."

For PP Waypoint Editor, right click the serial icon and under "Handshaking" make sure all the options are "OFF"

I am not a computer person and have no idea why this combination works, but it does. I wish UNAV could have figured this out -- or, better yet, worked out the hardware/software issues to make the device USB plug-n-play -- but in the meantime this will suffice, at least for me.

EDIT: Another thing UNAV should clarify is that the Mapsource route must be made with the waypoint tool, not the route tool. When maps are made with the route tool and then saved as a txt file, they will not import into PP Waypoint Editor.

-- Bob

[cmoulder]

My Tele is almost ready to fly. However, weather will be the deciding factor for some time to come, and it is snowing now with 2-1/2" of new stuff and it will keep falling for quite a few hours more.

I went ahead and installed both Picopilot and video system during the assembly. I got a Hauppauge WinTV HVR-950 TV tuner for the laptop, which was very easy to install and permits video monitoring and recording. So the laptop, while not fully optimized, is at least solidly functional for the basic requirements of programming Picopilot and handling the video chores.

The AUW of my plane is 8 lbs 12.3 oz according to my digital postal scale. This includes 2 Thunder Power 3s 4500-mah lipos in parallel (3s 2p 9000 mah), 3s 900-mah for the video, 2s 2000 mah for Rx/PP, and 3s 1050 mah for the GPS receiver. Miraculously the CG is 4.5 inches with no ballast.

At this point there is zero telemetry, so at first I will have to monitor things the old-fashioned way by doing short flights and then landing to do battery checks. Fortunately I have a little experience with higher output systems, such as 3D electric airplanes, and it seems the propulsion system will not be pushed hard at all.

I have nothing but admiration for Jeff Parisse and his "best practices" installation in his Tele Electro. Mine looks like a rat's nest, but this is due largely to all the excess wire from servo extensions and regulator wires and charge port wires and buffer wires and PP input/output. I was loathe to trim any of these, however, because this is just my test bed and I hope to do a more permanent install in another plane later. In that event, I will shorten and solder the wires to the needed length.

I will post some photos later. Doing the ground station assembly today.

-- Bob

[icebear]

Sounds great Bob! Well done on the Vista too...
Looking forward to the pics.
I see what you mean with the rat's nest - Jeff's standard here is certainly high!

Cheers,
Bjorn

[spirko]

I’m adding to this thread because it helped me yesterday setting up a new PicoPilot NA, on a MacBook Pro running Windows XP.

After trying four different RS232-USB adapters, the one I found that works is a Radio Shack 26-183 USB to Serial Cable. It’s big and it’s beige and it’s ugly, but it comes with driver software and I can now edit waypoints. (others had software, but I couldn’t get them to work. I also tried the null-modem adapter without success.)

After installing drivers from the CD, Open: control panel / system / hardware / device manager / ports (com & lpt) / RadioShack USB-to-Serial Comm. Port (COM1)

PicoPilot needs to be on COM1, and if it’s not, (mine installed as COM3) click on Port Settings, then Advanced, and there’s a scroll-down menu for “COM Port Number.” Make it COM1 and you’re there.

I know I’ve written this for novices, but my knowledge of Windows is almost exclusively for r/c: Flight sims, Eagle Tree data recorder, etc., and I figure maybe I can save someone a few hours setting up their PicoPilot.

[kd7ost]

Nice addition spirko. Many will thank you.

Dan

[cmoulder]

spirko, good idea to post your solution, as I did with mine. I spent about 3 days banging my head against the wall before I figured it out with Vista.

What is your airframe?

[spirko]

Moulder,
I’m using a Dreamline 1.8 meter sailplane (esprit model), mostly because of the low wing loading, (5-6.5 oz/sq. ft.) with an eye to eventually buying a $1,000 worth of spectrolab solar cells and making the aircraft self-sustaining as far as power goes. I don’t know if it’s going to be stable enough for the PicoPilot, but the u-nav website kept noting how good it was for electric gliders and how one didn’t need extra wing leveling. I’ve got a FMA co-pilot I could throw on if necessary, but I’m running quickly out of room in the fuselage for components and wires.

[rclinks2002]

Hello Everyone,
I recognized a few of the people subscribed to this list so I figure it would be a good place to try. I am having a problem with my picopilot again. I load the waypoints in the unit, but when I go to fly, it almost seems that there are no waypoints loaded, and the plane just circles around the start point. Any Suggestions?

Thanks again
Ben Mitchell

[cmoulder]

Hi, Ben:

What is your procedure when uploading routes? Are you uploading at home or at the field?

I ask this because I had some problems early on uploading routes until I followed exactly the procedure outlined on page 10 of the PicoPilot manual -- at the field.

There is a note at the bottom of that page that says "The autopilot must be operating and connected to the computer's serial port before the Waypoint Editor can display any data." I would amend that phrase "operating and connected, BUT NOT ENABLED".

Also, note the route format and lat/lon format on page 11.

If you are not getting the route waypoint readback from PicoPilot to your laptop (in Waypoint Editor), then the route is not loaded.

Another thing I recall is that in order to get the routes into the proper format with MapSource I first made my waypoints as individual waypoints, then selected them all and did a 'convert to route' in MapSource and then saved in the Text (TAB delimited) (*.txt) format, so this might be the issue as well.

This is definitely not a breezy plug-n-play system, but if you jump through all the hoops the results can be very satisfying. I am now in the process of transferring my system from the Telemaster Electro into the Senior Telemaster with a Zenoah g20 gas engine. I will be posting a thread on this soon. I hope it works out with the gas engine!!!

-- Bob

[rclinks2002]

Bob, thanks for the information, I have tried uploading waypoints at home and at the field. They are uploading and saving on the autopilot. When I uploaded at home, I still checked to make sure they were still programmed in at the field. For accuracy and concerns with google earth, I acquired the waypoints using a handheld GPS unit. Another problem I am having is that the unit will only fly a right hand circle overhead (the return to home waypoint) If I activate the autopilot when a left turn is clearly the correct direction to fly, the plane enters into a deep left spiral and does not recover. Before each flight I check the control throws of the autopilot and they check out correctly.

I have posted numerous questions along these same lines and nothing seems to fix the deep left spiral problem. I beleive the unit is somehow defective. It has been involved in a crash but it was well padded and there is no damage to the board that I know of. It has done the spiral problem since day one. Thanks for your help

Ben Mitchell

[cmoulder]

Hi, Ben:

It might be a defective unit, but there also other problems that could cause this, such as the gain settings on the N and A boards. If you have not done so, I would suggest starting with a very low setting -- perhaps 15% -- and then gradually work up from there if necessary. Alternatively, if you have the gains set low, start working your way up. Sounds as if it might need a bit more gain on the 'N' board (??)

Are you using the NA unit or the NAT? I found out that the 'T' board causes more problems than it's worth, causing a hysterisis to set in as it fights with the A board for control. Better to just use a programmed throttle setting with PP enabled, making sure that the Receiver's F/S does not conflict with PP-enabled state.

Which airframe are you using? I know the manual states that a 3-channel motor glider (rudder control) is the ideal platform, but I would want a wing with double dihedral in that instance. Personally, I prefer a model with ailerons any day. The Telemaster Electro -- with coordinated ailerons and rudder -- seems to be a very successful platform for PP.

This leads me to ask, what are your control surface throws, and if using ailerons, do you have a lot of differential -- i.e. 50% down vs 100% up?

Clearly, all the variables make it difficult to diagnose problems. :confused:

-- Bob

[kd7ost]

Also,

What is the vintage of the firmware? I don't know the version number cutoff point, but early units used a "Waypoint arrival" sequencing system. Once the Pico unit was within .1 mile of the selected waypoint it would sequence to the next waypoint. This is OK on a large route with a fast plane and is how full scale operates. But with slow flying planes and small routes there was an issue. If you load waypoints that are within .1 mile, then try to fly, the sequencer would see the first point was made, then move to the next. Then see that the next waypoint was made and move on again. Then see the next one was made and so on. It looked like the unit wasn't going to the waypoints because they were all in range of the sequencer.

The current version uses waypoint departure sequencing. In this case the waypoint needs two conditions to move on. First it had to get within range. Then it had to see an increase in that range indicating the aircraft was now passing the waypoint. Only then would it sequence to the next.

After that, I agree that proper set up of the plane, throws and gains are very critical. Generally the throws in the plane, as activated by the Pico unit, will need be less than what you use to actually fly the plane with. You don't want fast turn rates as it can adversely effect the flight capabilities of the plane. Wind will effect the turn rate in this way. You might see the plane crank around pretty fast when flying into the wind due to increased airflow over the control surfaces. But down wind will be slow because of decreased airflow. This is normal and is a factor of air speed as sensed by the airframe and not gains. We see the same thing when we fly manually. But you can't optimize the setup for the slow turn. You must optimize it for the fast turn otherwise you risk over control. Toning it down is critical.

Dan

[icebear]

Bob and Dan has already given some sound advice, but I would like to add that trimming is critical for success too. Make sure the plane is trimmed for really straight and level flight when enabling the PP.
It could be that you have a too low gain setting and if you are a little out-of-trim, then the autopilot cannot turn in more than one direction.

Post some more info on airframe etc and I am sure you can get more recommendations!

Bjorn

[cmoulder]

Bjorn, this makes me think...

If the aileron differential is not adequate and rudder is not coordinated with alierons -- and given the right set of conditions with gain settings -- I can imagine a plane spiralling in the manner described.

Had I not followed closely the advice gained here with my Tele Electro, I doubt seriously I could have gotten it to work so well so quickly!

-- Bob

[icebear]

Bob,

You are right, when I setup my NSP Viking I had too much mechanical throw and even on low gain I would get a spiralling descent.
Reducing throw and adding the Veetail mixer for rudder (like workshop/Jeff did but reversed - I mixed ailerons into rudder, but the result is the same) solved the problem and now it is very stable setup.

Bjorn