Quad Cc3d Fc Rx Problem

[FlyByKnight22]

Hello everyone,

This is my 1st Tech Help post in this forum.

I apologize in advance for it being so lengthy but I wanted to be sure that I included enough information to give a good idea what’s going on.

I am building a ZMR-250 Class Racing quad for my Son using the Afro Race Spec 20 amp 4 in 1 + CC3D Flight Control board but I can’t get it to work with my Devo RX701 receiver.

I saw a YouTube video regarding RC-Help.com on how to configure the CC3D Flight Control board and that led me here for more help as that did not resolve my problem.

Here is that link for reference:


After looking through most all of the posts here on this forum for a possible solution to why I can’t connect/Bind to my receiver after connecting a battery to the newly configured CC3D board, I decided it was time to swallow my pride and ask for some help.

Hopefully someone else may have had the same problem.

I am using the following equipment:

Walkera Devo-7 Transmitter, Devo-RX701 receiver, BR2205 2300KV Race Star Motors, an Afro Race Spec 20amp 4 in 1 + CC3D Flight Controller with one shot Simon/BLHeli ESCs, Multi-Star 1400mah 3-cell 65C battery on a ZMR250 carbon frame.

Here is a diagram and photo of the Afro Race Spec 20amp 4 in 1 + CC3D Flight Control board:




Symptoms:

After successfully flashing the CC3D FC board using OpenPilot, version 15.02.02 and successfully going through the initial Setup Wizard (using PWM, Rapid ESC timing, calibrating ESCs, motors spin up, correct rotation, etc, etc etc) and saving this to the CC3D FC, the program finally takes me to the “Transmitter Setup Wizard”.

At the “Transmitter Setup Wizard” as I try to start to go through it, I connect the battery but OpenPilot does not see the TX. The RX701 receiver red power light does not come on, indicating that it is not getting power or bound to the TX.

Here is where I am stuck. Nothing I have done so far has allowed me to get power to the RX701 from the CC3D board break out cables to power up the RX so it will Bind to the Devo-7 to finish the “Transmitter Setup Wizard” in OpenPilot.

Background:

I had previously bound the RX701 to the Devo-7 TX before starting the CC3D config in OpenPilot, with fixed ID using a separate external ESC for convenience. During that process I connected a servo to each channel of the RX701 to verify I could drive the servo properly, which I can do so the RX701 seems to be operating properly.

My RX701 receiver is connected to the CC3D board according to this picture:







I checked the color code of the wires for this CC3D board and a few different other CC3D variants around the Internet. It seems there are at least several different color schemes for the break out cables that go from the FC board to the RX.

My color code on this Afro 4 in 1 + CC3D board are tri-color= White-Red-Black, Yellow, Green, Blue, Purple and Grey in that order on the break out cable coming from the CC3D FC board.

As shown in the previous photo this is how they are connected from the CC3D to my RX701 receiver:

Elevator- Tri-Color

Aileron- Yellow

Throttle- Green

Rudder- Blue

Gear- Purple

Aux1-Grey

I tried a different receiver and protocol with the Spektrum AR6100e on the CC3D and had the same results in the Transmitter Setup Wizard, which was no response in OpenPilot to the stick movements from the Transmitter and no power light showing that the AR6100e was not on or bound to the TX.

Before trying the Spektrum RX I also Pre-tested and Pre-bound it the same way I did the Devo-RX701 using a separate ESC/battery and did servo movement operation with it on all channels to verify proper function before connecting to the CC3D FC and those tests were good.

The video link linked above from RC-Help.com, talked about swapping the white wire for the blue wire in the tri-color cable connector to make it Blue-Red-Black instead of White-Red-Black but that did not fix the problem either so I put it back to its original White-Red-Black config.

I have connected the RX701 several other different ways to the break out cable from the CC3D FC Board with the same results described above.

At this point I’m not sure what to try next except perhaps another Flight Control board.

I haven’t tried flashing the CC3D board with LibrePilot software or CleanFlight to see if that changes anything but thought, if I can’t get power to or Bind the RX with it connected to the CC3D in OpenPilot, that the same thing would happen in the other GCS variants, as it “appears” to be a hardware/wiring problem.

Perhaps someone has some thoughts or ideas that might resolve this problem.


Best regards to all,

Respectfully FlyByKnight22

 

[Tony]

Lets start with some basics and go from there.

Have you powered up the FC and used a voltage tester/meter on the red and black wires to verify you are getting 5vDC? If not, lets do that just to make sure we are getting power out of the board to the receiver. If you have done that, and you are getting voltage out, try putting the red and black wires in the battery port. I'm not sure about that Rx, but some are picky as to where they want to receive power. Most times, the positive and negative are bridged between all pins, but sometimes, there is an in, and and out. Just covering bases here.

It shows there is a switch on the under side of the FC, have you verified that it is in the On position?

Lets start there and see where we land. I'm going to have to do some research on that board.

 

[FlyByKnight22]

Lets start with some basics and go from there.

Have you powered up the FC and used a voltage tester/meter on the red and black wires to verify you are getting 5vDC? If not, lets do that just to make sure we are getting power out of the board to the receiver. If you have done that, and you are getting voltage out, try putting the red and black wires in the battery port. I'm not sure about that Rx, but some are picky as to where they want to receive power. Most times, the positive and negative are bridged between all pins, but sometimes, there is an in, and and out. Just covering bases here.

It shows there is a switch on the under side of the FC, have you verified that it is in the On position?

Lets start there and see where we land. I'm going to have to do some research on that board.

Tony,

You have a good eye sailor!

Checked white/Red/Black Tri-Color cable for voltage. Results = 0 volts.

Switched ESC firmware update switch from off to on. Results = RX701 Red power light illuminates and Devo-7 TX binds correctly.



Re-Started “Transmitter Setup Wizard”.
Results = Still does not work/respond to TX stick inputs.

Disconnected battery power, turned off TX and selected disconnect button on OpenPilot, then disconnected usb cable from CC3D and PC.

Changed CC3D break out cables going to
Devo-RX701 to the following:

Elevator = Blue wire

Aileron = Yellow wire

Throttle = Tri-Color White/Red/Black wire

Rudder = Green wire

Gear = Purple wire

Aux1= Grey wire

Hooked everything back up and started “Transmitter Setup Wizard” again.
Results = Transmitter Setup,... COMPLETE!

Saved then closed out the Wizard in OpenPilot.

Removed CC3D from PC, removed usb cable and Cranked the ZMR-250 Up with props removed to check that all controls work correctly and they do.

It acts like it needs lots of tuning and tweaking but I now have a basic functioning racing quad.

Thanks Tony, you’re the man!

“I like that in a Pilot”

Aftermath:
The standard written instructions for cable connections for all CC3D FC boards to a Devo-RX that I have seen are wrong and cannot be used to hook it up the way they instruct you to.

The blue-white wire swap for the Tri-Color cable fix illustrated in the previous video link posted above appears to be a Spektrum specific requirement and definitely not to be done for a Devo receiver.

Here is the photo of the correct wire connection sequence for the Devo-RX701 and the Afro Race Spec 20Amp 4 in 1 + CC3D FC in case anyone else runs into this problem:



Best Regards,

Dennie,

Master Chief United States Navy (Ret.)

 

[Tony]

That is awesome that you got it working. I saw it had that switch and figured that would basically kill all BEC power going out of the board. Glad that was the issue.

And yes, Spektrum uses TAER (Throttle, Aileron, Elevator, Rudder) sequence, and a lot of others use EATR such as yours. So in this case, my video and the wiring I did will not work. But once again, I'm glad you got it figured out! Now we just need to see a maiden video

 

[FlyByKnight22]

That is awesome that you got it working. I saw it had that switch and figured that would basically kill all BEC power going out of the board. Glad that was the issue.

And yes, Spektrum uses TAER (Throttle, Aileron, Elevator, Rudder) sequence, and a lot of others use EATR such as yours. So in this case, my video and the wiring I did will not work. But once again, I'm glad you got it figured out! Now we just need to see a maiden video

Yeah, me too Tony.

I worked in the computer/electronic industry for many years in the Navy and civilian community in repair, support, as a Wireless Broadband Engineer and BioMedical Engineer.

I have seen how easy it is to “brick” a motherboard and other devices with an improper firmware flash and was trying to be careful not to trash this little board by following their process.

I had been staring at that mini-switch for awhile, wondering if that might help but wasn’t sure as the step by step Chinese instructions that came with this board didn’t include that in their Setup Wizard.

Should have been obvious I suppose but when giving or writing instructions for someone to follow who has never done it before on this particular board, I think it’s important not to “assume” anything.

Your video was still helpful Tony and well done I thought and the info about the cable change in the connector for Spektrum receivers is still good to know and might come in handy later on down the road if my Son decides to change out the receiver.

It’s always good to have another set of eyes on a problem, especially after you have been staring at it for too long, like myself in this case.

Being a little redundant here but again there didn’t appear to be anything in the setup Wizard or instructions that I saw or could find about this specific board, regarding changing the micro-switch position after flashing/configuring as OpenFlight goes immediately into the “Transmitter Setup Wizard”.

In addition, the videos that I looked at for configuring CC3D, were fairly generic and I don’t recall anybody mentioning a micro-switch much less changeing it’s position but then again, this Afro Race Spec 20amp 4 in 1 + ESC has very little info out there to find anyway.

This board is fairly cheap and quality seems a bit suspect. I did see a number of folks having issues with it, contacting HobbyKing and others etc for a solution but getting zero answers.

They need to come here, don’t they Tony!

Anyone who has flashed the firmware on a CC3D before would/should know about the micro-switch (assuming they all have one?) but not a first time user of the board like me.

Because the micro-switch is shown in a diagram only and not mentioned in the step by step setup process/instructions, I thought it might be a good idea if I posted the picture here for your and others review. I tried to paint a picture of what I was seeing, I hope I did that.

The wiring comments in all the different CC3D instructions that I looked up, trying to get it to work, basically said that it doesn’t matter how you hookup the break out cables to the RX if using PWM, as it’s claimed OpenPilot sorts that all out in the GCS software Setup Wizard.

Not so, at least in this case.

Having said all that it seems to be basically working now but there is quite a bit more work to do in PID tuning.

I notice you have a thread on PID tuning and I will be taking a hard look at that.

I need to go back through the Wizard and bump up the idle speed for each motor as it seems too low and the motors are somewhat lethargic, with even one or two motors periodically stopping when using the pitch, roll and yaw controls.

I realize that the individual motor speeds must change while maneuvering but I’m somewhat concerned about a total stop of a motor while in flight.

Lots of major tuning appears needed before this is a reliable flying quad that I can give to my Son.

I used the closest uav file I could find in the GCS software during the Setup Wizard but nothing really matched my motor/ESC hardware so I might search for a better match. I used the standard ZMR-250 file like I think you chose in your video.

I found a “Sport Racing Drone” SDR-250 V2 on helipal’scwebsite that uses mostly all the same components as my build (same motors, CC3D, RX,TX, props, ESCs, frame etc) and they have a uav profile download that I might try if I can’t get it tuned to suit me using OpenPilot.

Maiden looks like it may be awhile yet Tony but I’ll upload here when it gets sorted out.

Thank you again Tony for your patience and expert help.

I will be telling all my RC Homies to Check you guys out here at RC-Help.com.

Best Regards,
Dennie

 

[Tony]

Thanks for that Dennie, I'm just glad you got it all working. Don't be worried about the maiden flight, just make sure to have plenty of props on hand. These frames are quite strong, in fact I have flown mine into a T Post at almost full speed and all I did was dent a motor can and broke a prop. So have plenty of props on hand. And by the way, the 5045 props you have are perfect for this little guy. It's what I run most of the time, but I'm finding I really am liking the 5051 Gemfan props.

If you take a gander in the manual, you will see them mention the switch when flashing the ESC. They wanted you to have it in the Off position when flashing, then On after flashing for normal operation. This is the only thing that lead me to ask about that switch. I have never even seen or heard about this board and was basically spit balling this one. Turns out I hit a bullseye. Call it luck, but it worked lol.

As for the PID article, I tried to write something that everyone could understand. Diving deep into what Proportional, Integral and Derivative means and how they work will either put someone to sleep, or put them in a coma.... It's very confusing, but when you break it down it starts to make sense which is what I tried to do. Let me know if it helps out.

 

[FlyByKnight22]

Thanks for that Dennie, I'm just glad you got it all working. Don't be worried about the maiden flight, just make sure to have plenty of props on hand. These frames are quite strong, in fact I have flown mine into a T Post at almost full speed and all I did was dent a motor can and broke a prop. So have plenty of props on hand. And by the way, the 5045 props you have are perfect for this little guy. It's what I run most of the time, but I'm finding I really am liking the 5051 Gemfan props.

If you take a gander in the manual, you will see them mention the switch when flashing the ESC. They wanted you to have it in the Off position when flashing, then On after flashing for normal operation. This is the only thing that lead me to ask about that switch. I have never even seen or heard about this board and was basically spit balling this one. Turns out I hit a bullseye. Call it luck, but it worked lol.

As for the PID article, I tried to write something that everyone could understand. Diving deep into what Proportional, Integral and Derivative means and how they work will either put someone to sleep, or put them in a coma.... It's very confusing, but when you break it down it starts to make sense which is what I tried to do. Let me know if it helps out.

You are welcome Tony.

I do have a healthy sized bag of props on hand

I’ll have to take a look at those GemFan props, thanks for the heads up on them.

I’ve purchased various GemFan props in the past for testing with my Turnigy Thrust/Wattmeter combo stand, with different motors used for my fixed wing aircraft but didn’t like any of my results as most were too flexible at WOT and unbalanced but with these quads, we are talking about a totally different kind of bird for sure so I will definitely give those 5051s a try. I’m guessing that they are much more rigid compared to what I have already tested.

Yeah I must have missed the info about the switch in the step by step instructions. The manual uses such small print that it’s slmost impossible to read even with a pair of good eyes, which mine no longer are.

Anyway, it’s the only excuse I got

Thanks again Tony.

Best Regards,
Dennie

 

[Tony]

Small print, they are known for that. I was very surprised when I received my StackX flight controller that it has actual double sided, glossy printed 8.5x11 sheets of paper for the manual. 4 of them! lmao. I was not expecting that. But for over $100 for a flight controller stack with camera, I guess it is to be expected.

As for the crash that I was telling you about, here is the quick little video of that. I was having a camera issue which I was working on at the time, it was just over exposing the image really bad. And I apologize, it ends the video very abruptly after the crash lol. Pieces flew off hahaha.


And here is my Darkmax quad running on 4s using those 5051 Gemfan props. They are fantastic props but watch that tip, it's quite sharp lol.


I'm also putting those same props on the new quad build that I have yet to start. Guess I need to start that today lmao.

 

[FlyByKnight22]

Small print, they are known for that. I was very surprised when I received my StackX flight controller that it has actual double sided, glossy printed 8.5x11 sheets of paper for the manual. 4 of them! lmao. I was not expecting that. But for over $100 for a flight controller stack with camera, I guess it is to be expected.

As for the crash that I was telling you about, here is the quick little video of that. I was having a camera issue which I was working on at the time, it was just over exposing the image really bad. And I apologize, it ends the video very abruptly after the crash lol. Pieces flew off hahaha.


And here is my Darkmax quad running on 4s using those 5051 Gemfan props. They are fantastic props but watch that tip, it's quite sharp lol.


I'm also putting those same props on the new quad build that I have yet to start. Guess I need to start that today lmao.

Wow Tony!

The Furibee flies purty dang wicked.

I forgot to mention that I also have a Walkera Furious 320 and It flies,... ignorant

It’s amazing that the 250 Crash into that post didn’t completely total the quad.

The crash caught me by surprise even though I was expecting it. I kinda thought there for a sec,.. “Ah Mav will probably pull up at the last second”,.. boom!,.. didn’t happen

Nice videos, still thinking about the punch out that the Darkmax has. Very powerful little dude right there.

Best Regards,
Dennie

 

[Tony]

Yea, in my goggles I couldn't see that T post. By the time I did see it, there was nothing I could do lmao. And yea, that Darkmax is a little monster. I'm building another one that should be just as powerful if I can get the parts I need to shorten the FC stack so it will fit. Not sure if it will work though. But we will find out some day lmao.

 

[FlyByKnight22]

Here you go Tony,

I promised a maiden but this is probably more of a shake down cruise.

She’s Pretty much all together now.
I still have to mount the camera, install the navigation lights and low power alarm warning lights but it’s flying well already with just some minor tuning.

I selected the standard ZMR-250 uav profile from the OpenPilot menu, then gave it a quick flight inside the house. It was twitchy but flyable.

Turned the rates down about 25% and added a small amount of expo (20%) to elev, aileron and rudder.

After those adjustments I flew the ZMR-250 again in a space of about 8’ by 10’ for a couple minutes and it’s much better now.

I didn’t notice any oscillations but I didn’t have the room to drive it very hard. It flies nice enough and is stable and is easy to control. She really wants to go

My Son’s birthday is this weekend and if the weather clears up I’m sure he’ll give it a good run out.

Here is a short flight video:
“A really old Navy ZMR-250 build”


Best Regards,
Dennie

 

[Tony]

It definitely looks nice and stable, that's for sure! But you are right, it wants some open air to get out there and do some moving! lol.