[Bragster]

RCG that a couple of folks I have a lot of respect are flying it with something called Betaflight

I am using Betaflight on a CC3D, so much better than Cleanflight and works without tuning. The Cleanflight guy dropped support for Openpilot bootloader recently also, Betaflight kept it.

Openpilot flies better at top speed *if* you put in the time to tune it but Betaflight is easier to use.

[tywysoges]

As I reported a while back, I am helping a friend with his first quad and he got one of these.

There were a total of 2 soldering issues.  One on each board (Revo and OPLink).

The Revo had a solder bridge on the MainPort filter chip that kept the MainPort from working at all.  I fixed it and it works now.  He is using MainPort with a $14 eBay GPS.  Using the on board (Revo) mags.  Calibrated mags with USB (not recommended) and it works fine.  Flying in VelocityRoam so he can fly! 

The OpLink had a capacitor that looks like it became disconnected during a soldering operation.  It worked the way it was, but I resoldered the capacitor and it still works.

Both boards have been flight tested now and they fly fine.

I added a review on ThanksBuyer.com, 3/5 stars because of the two solder issues.  The review has not cleared moderation yet.  I wouldn't bet on it ever being posted.

I would buy one if I needed one, given the price drop ($50 for the Revo only, $66 for the Revo+OpLink, shipped) and the fact that they were repairable by me.  Buy them with PayPal and if they don't work, you can get your money back.

This is bad news. I have two new ones from banggood, they have problems can I send them to you to look at?
 
Where would I start to fix such issues, what is the process?

[TheOtherCliff]

(replied in other thread, start by making sure firmware is the same version as GCS and that you don't move it till fast blue and orange flashing stops)

[cato]

Back to the Revo Clones: Today I could test my Amazon Revo Clone again. The situation is still the same: I did a full erase and re-callibration and put it into my 450 Cinetank. In EKF mode the quad tried to flip, while in Complementary everything is fine. I guess it's safe to say, this clone is crap. It looks more like a sensor problem then a problem with CPU or boards.

Same procedure done with original Revo, and the Revo flies with no issue at all.

[Mateusz]

Back to the Revo Clones: Today I could test my Amazon Revo Clone again. The situation is still the same: I did a full erase and re-callibration and put it into my 450 Cinetank. In EKF mode the quad tried to flip, while in Complementary everything is fine. I guess it's safe to say, this clone is crap. It looks more like a sensor problem then a problem with CPU or boards.

Same procedure done with original Revo, and the Revo flies with no issue at all.

Complementary uses only Accel and Gyro, if that flies then it means that those sensors are fine.
Magnetometer and GPS which are additionally used in EKF mode and all problems related to that are usually comming from a bad calibration. You can try external mag and GPS. If it works in Complementary it should also in EKF if calibrated properly imo.

[TheOtherCliff]

FC mounted right side up and forward with normal motor numbering and directions?

Get it flying with CF in Attitude mode to make sure accels are correct.  With it flying like that, do some telemetry and watch to see of mag goes red (bad).  Or you can just carefully go to hover power in hand with USB cable attached (to watch mag color).

Flip will also happen if you have GPS V9 mounted backwards and are using the GPS V9 mag.

It can also happen with bad mag calibration or worse yet, bad high current wiring.  You must twist all high power wires or high throttle = high current (if props are on) = high mag field = bad mag signal = bad

[cato]

Well,

I deleted my last post, as after two more setups and one more frame change the FC works perfect. No idea why, because I did everything the same way. Well, two differences: I let the GPS set home position, and I did mag calibration quick and dirty, on my balcony

[cato]

I was talking with the trader, and it seems that similar problems occur often, so as it seems that my hardware is fine (well, except that ARM 2 is not as good as ARM Z, and the sonar port is missing), I would like to look for the reason for these problems. So as a start, I'll document the whole procedure which I did for a successful set up of the FC, as I did it two days ago. I would appreciate any comments. I will also try to remember what I did different before. So here my procedure:

- mount the revo, check correct orientation, connect the modem antenna, connect the receiver (FrSky X8R) to Main Port, the GPS to Flexi Port (this way external mag cannot be used, but I have 16 instead of 8 channels from the rx).
- make sure the props are removed.
- connect USB to PC (Debian Linux wiht LP GCS 15.09)
- upgrade the firmware, selecting Upgrade&Erase from Firmware tab, even though the firmware was already up-to-date
- run vehicle setup wizard. For the calibration check that the quad is well levelled (spirit level) and not moving. Wait a few seconds before saving
- run transmitter wizard.
- power cycled the quad
- let GPS find and set home position
- import the thermal calibration data. Make sure that ONLY thermal calibration data are imported
- perform board level calibration, making sure the quad sits stable and absolutely horizontal (spirit level again)
- perform gyro calibration, again making sure the quad sits absoltuely stable
- perform accelerator calibration. Make sure that the quad sits absolutely stable before hitting save
- perform mag calibration. I did this on a balcony, making sure all metal is about 3-4 meters away.
- setup flight modes as desired (I have 6 flight modes configured)

- check quad state in Flight Data Tab:
-- GPS green
-- mag green, does not go red when starting the motors
-- config tab green
-- artificial horizon follows exactly the movements of the quad
-- check scopes: no drifting sensors, reasonable senser levels

then in the garden with mounted propellers:
- mount props
- select rate mode and try to take off, push throttle, don't be too slow, don't try to correct attitude until the quad is airborne
- on success, select attitude mode and try to take off, again no compensation of attitude until quad is airborne
- on success, try to slowly increase throttle and intentionall try to compensate attitude.

All these tests were successful this time. Next step was flying it around in the garden, first hover, than stronger movements. Now I will check a true flight, several batteries, testing the different modes ...

[iceman]

I have a genuine revo that works great, but i've never had any luck with a clone. I bought 2 off ebay (different times, different sellers) and they were both DOA (or at least i could make them work) so i sent them back. I'm willing to try one more time because i only have the one and i love it and i want to build another quad soon.

ice

[TheOtherCliff]

Mag calibration should really be done away from building.  Also, one failure point with mag calibration is that it is always recording, not just when you press the button, so you cannot set the quad down or close to metal at any time during mag calibration procedure.

I can also imagine that very wrong home location would give bad values from world magnetic model, but I haven't looked into how we use magnetic inclination, whether that is known based on GPS location.

I would try to make the problem happen again, by redoing these things exactly like you did when it failed.  Must start by getting the problem to happen again. 

I'm glad you got it working though.

[cato]

I flew the clone today. It flies great it Rate mode, but in attitude I still identified problems. I had a strong drift. This may be a problem of board level calibration. I will go into that later, for now I went back to the original Revo.

Here the video:

[TheOtherCliff]

First of all, once you do transmitter wizard, you should never touch the transmitter trims.  (All right it is OK to use them temporarily, but you should put them back in the center and fix the problem that made you need to adjust trims.)

If it drifts in Attitude mode, you must use GCS -> Configuration -> Attitude -> Settings -> Rotate Virtual to correct it.  If it drifts backwards, you add positive Pitch to make it go forward.  If it drifts right, you add positive Roll to make it go left.

[ivan.lincheng]

hi guys,
A revo clone isn't big news, but be awared that their barometer may be unstable! Just check the barometer data first when you get it!