Ultra budget quad build.

cranialrectosis

Faster than a speeding face plant!
Mentor
The WQ is a well supported topic. Whether or not you fly a WarpQuad, if you fly small, powerful, acro copters, some of the best are online at that thread.

I love mine. It has survived some real crashes that would have smashed my Knuckle H quad and that just eggs me on to push it harder. I have some KISS ESCs in the mail so shortly I should be able to push harder without de-synching issues.
 

jhitesma

Some guy in the desert
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Yeah, there's a ton of great info on RCGroups...it's just exhausting to try and keep up with it :D Miss a day and suddenly you've got 10-15 new pages in every thread you're following :D
 

Billbo911

Member
Partially Verified FAILSAFE with 2.3 using PPM

I've been working my way through this thread for several days now. Riding the ups and downs and learning like a mad man, trying to catch up to the present. I still have 3 or 4 pages to go, but I had to follow up on something.

When you hit the problems with FAILSAFE and it not working with PPM, I started to get very concerned! I am running PPM and have NO DESIRE to go back to 4+ PWM jumpers.

I have just received a new Flip 1.5 MWC from RTFQ. It is slated for my next TriCopter. For now though, it will allow me to do some testing and diagnostics.

The bottom line is, FAILSAFE appears to work correctly, but only in certain failure modes, with MW v2.3 and PPM.


Notice I unplugged my receiver. In a loss of power to the receiver, FAILSAFE will kick in and run as configured.

BUT, I then tested again by just turning the Tx off, and the failure was exactly like your fly away. The output maintained stabilization at whatever throttle position it was set to at the time of the loss of signal. So, what seems more realistic, loss of signal, or loss of power??

I will configure the FailSafe mode on this Rx to cut all outputs and test it again.
[Edit] I just found out the lowest setting I can place each channel to for Failsafe mode on my Rx is ~1000, that is too high to trip the FAILSAFE Threshold for MW. Time to find an alternative solution![/Edit]
 
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Billbo911

Member
...
Few tips that I think are important:
- Last time I check MultiWii fail safe, I did see that the off-shelf fail safe is not something for me ... apparently fail safe get activated when the PPM or PWM signal are under 900uSec ... I simply did not like it. It is very specific to the type of RX used
- What I did, since I want to have fail safe logic on the control board and not on the RX (for most of usage fail safe on RX is good enough), I did program my FrSky PPM RX to just send "NOTHING" in case of signal lost ......

OK, I remember seeing this post earlier. Now that I NEED this information, just how did you set your Rx to send "NOTHING".
I do not see that in the manual for my FrSky D4R-II. It only tells you to set the stick positions and then it stores those for use in "Failsafe" mode.
 

jhitesma

Some guy in the desert
Mentor
You can change the threshold for failsafe in the config.h file look for this line:

#define FAILSAFE_DETECT_TRESHOLD 985

If the lowest you can get out of your TX is 1000 then you can set that 1001 - but you'll have to make sure that your endpoints are above that and make sure your minthrottle doesn't have to be raised to compensate for the higher endpoints.

You could try setting up your tx to send a lower value than 1000 just while programming the failsafe in your RX, then reprogram your TX with the endpoints you actually want before flying.
 

Billbo911

Member
You can change the threshold for failsafe in the config.h file look for this line:

#define FAILSAFE_DETECT_TRESHOLD 985

If the lowest you can get out of your TX is 1000 then you can set that 1001 - but you'll have to make sure that your endpoints are above that and make sure your minthrottle doesn't have to be raised to compensate for the higher endpoints.

You could try setting up your tx to send a lower value than 1000 just while programming the failsafe in your RX, then reprogram your TX with the endpoints you actually want before flying.

I thought about those options too. I'm just not quite ready to go there yet.
There are some posts showing how to get the Rx to output nothing in Failsafe mode, but so far, I have not been able to get my Rx to take on that configuration. Worst case, I can set up the Rx to output a centered Pitch, Roll, and Yaw with the Throttle just below a hover. That would allow a stabilized decent until either it landed or the battery died. All in all, not a bad option.
 

Billbo911

Member
FAILSAFE now working with loss of signal or loss of power.

I thought about those options too. I'm just not quite ready to go there yet.
There are some posts showing how to get the Rx to output nothing in Failsafe mode, but so far, I have not been able to get my Rx to take on that configuration. Worst case, I can set up the Rx to output a centered Pitch, Roll, and Yaw with the Throttle just below a hover. That would allow a stabilized decent until either it landed or the battery died. All in all, not a bad option.

All Righty!! I got the FAILSAFE mode issue figured out.

I proved that a power loss to the receiver would force MW to go into FAILSAFE mode. But if I just turned my transmitter off, the FrSky D4R-II just goes to it's Failsafe mode , which if it has not been programmed, is just the last known good values for PPM. I believe this is what may have caused your flyaway.
So, with a bit, quite a bit, of searching, I found out why I wasn't able to config my Rx to output NOTHING on loss of signal.
It is because if you leave the jumper on Ch 3-4 to force PPM, it will not reprogram the Failsafe mode.

So, here are the steps I needed to follow:
1) Remove the jumper from the Rx, and for good measure, the PWM cable on Ch 1.
2) Put the Tx into Bind Mode.
3) Put the Rx into bind, causing a Re-bind and clearing the Failsafe configuration on the Rx.
4) Power off both the Tx and Rx.
5) Power on the Rx only.
6) Click the "F/S" button the Rx, thus setting the Failsafe mode to NOTHING.
7) Remove power from the Rx and reconnect the PWM cable and jumper on Ch 3-4.
8) Power on both the Tx and Rx and verify that turning off the Tx will force the Rx to output NOTHING and that the MWC went into FAILSAFE mode.
 

jhitesma

Some guy in the desert
Mentor
My flyaway turned out to be because I didn't actually have failsafe enabled anymore and didn't realize it :( But I also believe there is an issue with my RX - I was using an openLRSng setup and I've been having problems with the MW suddenly deciding it's not going to accept the PPM signal anymore. Still not sure if it's a problem with the openLRS RX or with my controller. I was able to get it going again for a bit by swapping my arduino mega for a new one - but then a week or two later it stopped listening to the PPM signal again.

I don't have any other PPM capable RX's right now (I have a flysky PPM RX I'm building from scratch but haven't had time to work on it) and I don't have anything else setup that can listen to PPM so it's kind of hard to debug until I get another board or get another RX. For now I'm back to flying on my Flysky setup but I'm seriously considering picking up a FrSky TX module and RX at some point.

Loving your progress on your camera stuff BTW...hoping I can pick up a mobius soon and if so I'll be digging into the world of gimbal control.
 

Billbo911

Member
... I was using an openLRSng setup and I've been having problems with the MW suddenly deciding it's not going to accept the PPM signal anymore. Still not sure if it's a problem with the openLRS RX or with my controller. I was able to get it going again for a bit by swapping my Arduino mega for a new one - but then a week or two later it stopped listening to the PPM signal again....

As I've been reading through your thread, one thing keeps concerning me. I have lots of experience with Arduino in many of it's form factors. (One of my favorite things to do is Mentoring a FIRST Robotics team, and we use Arduinos for both prototyping and even on our competition robots for various functions.) What has concerned me is the Mega and connecting signals in and out of it. From experience, I can tell you that Murphy has a lot to say about the reliability of the connections. They are guaranteed to fail at the worst possible moment! Add to that, they will be intermittent failures that can not be reproduced during troubleshooting.
My suggestion? Solder to it whenever possible.
With you finally past the point of trying to keep it minimal budget, I feel comfortable in hinting that it may be time for a sensor integrated FC. (Just my $.02)

... For now I'm back to flying on my Flysky setup but I'm seriously considering picking up a FrSky TX module and RX at some point...
I am using the FrSky DJT module in my Turnigy 9x, flashed with ER9x, along with various FrSky RX's. I couldn't be happier! I don't want to sidetrack this thread with opinions on FrSky vs Futaba vs. Spektrum etc. etc. Let's just say, I made an informed decision when I chose FrSky.

Loving your progress on your camera stuff BTW...hoping I can pick up a mobius soon and if so I'll be digging into the world of gimbal control.
Thanks!!
It's been fun figuring out all the nuances, but I'm almost there. I just need to figure out how to get the GUI to work the way it's supposed to. For some reason, quite possibly me, it won't work in "Live" mode with any of my servos. I fly a Tri, so you can see how that might be a problem.
So, until I get it working normally, I must resort to hacking the code. (So far I know of two ways to make MW do what I want. But, only one works and the official way doesn't.....yet.);)
 

jhitesma

Some guy in the desert
Mentor
As I've been reading through your thread, one thing keeps concerning me. I have lots of experience with Arduino in many of it's form factors. (One of my favorite things to do is Mentoring a FIRST Robotics team, and we use Arduinos for both prototyping and even on our competition robots for various functions.) What has concerned me is the Mega and connecting signals in and out of it. From experience, I can tell you that Murphy has a lot to say about the reliability of the connections. They are guaranteed to fail at the worst possible moment! Add to that, they will be intermittent failures that can not be reproduced during troubleshooting.
My suggestion? Solder to it whenever possible.
With you finally past the point of trying to keep it minimal budget, I feel comfortable in hinting that it may be time for a sensor integrated FC. (Just my $.02)

The only connection issue I've had was actually my PPM wire at one point - and that was due to too many crashes causig the wire to break internally just past it's connector. And honestly even with fully integrated FC's 99% of people are still running connectors - just with the sex reversed (Pins on the board instead of sockets on the board.) Once I cleaned up my wiring with 90 degree pins so they are more protected in crashes I haven't had any issues with connections.

The PPM issues are perplexing...but don't seem at all to be connection related. I'm pretty sure my LRS is damaged from too many crashes since it rides on top and takes the brunt of many impacts.

And my use of the mega is anything but low budget at this point having replaced it three times - it's mainly because I have other things I want to experiment with that just wont' be possible with a traditional controller. The flexibility and options availble with this setup are the reason I've stuck with it. If I was wanting this just for flying and not as an experimental platform I'd probably have swapped to a Flip board a few months ago since I could fit it internally well protected and super clean.

But I still want to play with driving my RGB LED's from the arduino, some GPS related stuff, and a few other ideas floating in the back of my head I'm not quite ready to share yet ;)

I am using the FrSky DJT module in my Turnigy 9x, flashed with ER9x, along with various FrSky RX's. I couldn't be happier! I don't want to sidetrack this thread with opinions on FrSky vs Futaba vs. Spektrum etc. etc. Let's just say, I made an informed decision when I chose FrSky.

Budget is the main reason I've stuck with the stock FlySky stuff on my 9x. I do have an Orange DSM module because I want to be able to fly BNF's the next time my wife mistakenly buys me one as a gift instead of having to return it ;) (And it's letting my fly my friends Warp while he's out of town since the Spektrum Sat works so well on that setup.)

FrSky is by far what I would choose if I was to invest in a more robust 2.4ghz system. But my interests mostly lie in park flyer foamies and longer range stuff that 2.4 just won't handle - hence my jump to openLRS.

At some point I do plan on picking up some FrSky gear...but the budget and need just haven't been there.

Thanks!!
It's been fun figuring out all the nuances, but I'm almost there. I just need to figure out how to get the GUI to work the way it's supposed to. For some reason, quite possibly me, it won't work in "Live" mode with any of my servos. I fly a Tri, so you can see how that might be a problem.
So, until I get it working normally, I must resort to hacking the code. (So far I know of two ways to make MW do what I want. But, only one works and the official way doesn't.....yet.);)

I wish I had something to suggest on your issue but all I can think of is trying an eeprom wipe which I'm guessing you probably already have. Not sure why but I've seen the eeprom get corrupted in odd ways quite a few times with MW when experimenting and that's the kind of symptom I see when it happens. I did have a similar problem with my minimOSD where changes in the GUI weren't saving - but that turned out be due to using my FTDI adapter at 3.3v instead of 5v. It would connect and all seemed to work well at 3.3v but nothing would actually write to the eeprom. I'm guessing that's not your issue though so I haven't mentioned it.

When I do get a cam and get stabilization setup my big concern is I don't want to give up any of my aux channels but I do want to be able to adjust my camera angle manually. I have a few possible solutions but since I don't have a cam yet...I once again haven't looked very far into them yet :D

Almost pulled the trigger on the mobius last night...but we've got a vet appointment for the dog tomorrow and I know it's going to cost more than I expect (because it always does anymore) so figured I better play it safe...maybe next week it's looking like I can make that happen finally...we'll see.
 

jhitesma

Some guy in the desert
Mentor
So with the warp only in my hanger for another week I'm really itching to get a camera to start experimenting with on my budget quad. This was a double paycheck week (wife and I both got paid the same week) with very few bills so it's one of the few times in the summer my hobby budget gets re-inflated a bit :)

Checked Amazon and Ebay for Mobius's this morning. Amazon sellers were all either too high priced, didn't do prime, and/or were out of stock. Ok....ebay then.

Limited it to US sellers since I'm willing to pay a bit more for shipping to have it here sooner, hopefully before I have to give the warp back so I can try strapping it on there for a little spin....

Lots of options in the usual price range...but what's this...an actual auction instead of buy it now on a new Mobius? Only two hours left? It's only at $62!? Hmmm. Free shipping from the US listed as new....why not it's worth the gamble. Put in a $75 bid figured I'd get sniped at the last minute and it would go for the usual $80 price range that they go for as a buy it now. Got an e-mail while I was at lunch and what's this...I won the auction?! For only $66.50?! Score!

Well, hopefully. We'll see if the seller actually ships quickly and if it really is new. But I'm cautiously optimistic ;)

Time to start building an isolation tray this weekend in case it does arrive Thursday as predicted :D
 

jhitesma

Some guy in the desert
Mentor
You know, compared to RCG this forum seems slow...but after going back 5 pages to find a post that was last updated just barely a week ago seems to indicate it's not as slow as it sometimes seems :D

Camera arrived today! Interestingly enough even though the e-bay seller was a random person with only 4 feedback and an account just a week old the cam came from spytec in NY packaged in an Amazon box with Prime tape on it as if it was shipped from amazon. Odd. I almost ordered it on Amazon from them but they were listed as out of stock. Funny that I seem to have ended up getting the same cam from the same people faster and cheaper :)

Charging now but did a few quick tests and it seems to work just fine. Wife has today off so after work I'll do a bit of quick work with velcro and see if I can't get some hat cam of the warp and fix this on the budget knuckle for a little aerial video test :D