[TheOtherCliff]

Bridging the toggle pad with a 0 ohm resistor is standard engineering practice for boards assembled by machine.  Normally the second pad set's "resistor" is specified as DNP (do not place) and left open.  Only boards hand assembled would normally have solder bridging them.

I haven't used it yet, but I just measured the factory shunt (that is supposed to give full power from the ESC servo connector to the RC receiver) on my clone Sparky2, and it is 1k!  Yet another cloner problem.  I guess it is common for the cloners to just sweep the floor and use whatever they sweep up.

[TheOtherCliff]

Just a quick heads up
http://www.xt-xinte.com/F16821.html
From the photos they seem to be using the correct regulator now.. but still bridged the 5V toggle pad with a resistor .

I have heard of good and bad regulators shipped from the same seller.  I would not trust any of them to ship a correctly made board.  Always assume there is something wrong with it and fully test it as soon as you get it.  Make the ones that produce bad boards regret doing it and maybe some year the boards will be better, in the mean time, you will save yourself some money by getting your money back or a reship of a good board.

Also, always pay with a method that allows you to get your money back from a bad seller.  I used to think that PayPal was the best for this, but lately PayPal is not so good.  Thanksbuyer.com shipped the wrong item.  They wouldn't admit it even after posting two sets of pictures.  I had to get PayPal involved and the only reason I didn't have to pay return shipping on wrong item sent, just to get a refund was that PayPal had a "special offer" to handle it for free for a few months around Christmas.  Read that "don't expect that in the future".

[hwh]

I haven't used it yet, but I just measured the factory shunt (that is supposed to give full power from the ESC servo connector to the RC receiver) on my clone Sparky2, and it is 1k!  Yet another cloner problem.  I guess it is common for the cloners to just sweep the floor and use whatever they sweep up.

It's almost hard to blame the Chinese cloner for that one, the Tau BOM lists them as either NP or 10k.  I'm surprised they didn't populate both the jumpers, R15 and R17.

[onecooler]

Hi All!

I have purchased a Revo clone from eBay a couple of weeks ago and now having problems in AltitudeVario mode. What I have done only one test so far (due to bad weather), but it makes me worry about baro. The altitude graph looks to be within 1 +- meter, but when I enable altitudevario  flight mode, quad starts gaining altitude intermittently. It looks like someone giving it a full throttle for a half of a second then hover for the same time and then it starts over again. Is it a baro issue or it is something I have missed during software setup?

Thanks in advance!
-K.

[Drifter]

Gday onecooler, not sure if you are aware or not but the baro needs to be covered with a piece of foam, preferably a dark colour, to shield it from sunlight which will cause the symptoms you mention.

[onecooler]

Gday onecooler, not sure if you are aware or not but the baro needs to be covered with a piece of foam, preferably a dark colour, to shield it from sunlight which will cause the symptoms you mention.

Gday to you too and thanks for the answer. I have a Chinese clone that has already been packed in plastic case. Inside of the case seller already put a dark piece of foam. However I have not opened the case and did not check how accurate it is covered. I think to disassemble it and revisit now.
Thanks.
-K.

[darkdave]

My Revo is already encased in plastic. Is that good enough? I had the same problem with altitude holding not working properly and the drone jumped up and down. But the drone was flying under very cloudy grey skies and there wasn't much sunlight at all.

Are you sure the problem is sunlight? If I fly it at night will the problem go away? I had the same problem flying the drone in doors and the drone hit the ceiling and fell back down on the ground.

No sunlight there!

Last question: What if I bought an openpilot mini clone? Would that solve the problem? Or does the mini clones also have bad barometers?

[f5soh]

Baros are fine, just regulator that use same capacitor as original design but they changed the regulator.
https://librepilot.atlassian.net/wiki/display/LPDOC/Altitude+Hold#AltitudeHold-Hardwareissues

I don't know OpenPilot Mini, whats that ?

[Mateusz]

Are you sure the problem is sunlight? If I fly it at night will the problem go away? I had the same problem flying the drone in doors and the drone hit the ceiling and fell back down on the ground.

There can be many reasons (bad regulator, bad sponge, light, PIDs).
More powerful quad might require different altitude hold PIDs, than less powerful one. You should look into tuning those PIDs. They are called Vertical Velocity PIDs and can be found in GCS -> Configure -> Stabilization -> Altitude Hold
Try decreasing Altitude Proportional from 70 to 20, and Velocity Integral from 100 to 20, or play with those values. That that resolve the issue of jumps and downs ?
For me that helped, however making those values too low will cause that quadcopter will hold altitude well if no input but drop slightly when you move it. So you need to flatten throttle curve in the middle to get smoother 50% and play with values to find the sweet spot that works for you.
Those PIDs are not the same as stabilization PIDs.

[darkdave]

Thanks for this advice, I have made the changes and will try flying my drone in the park tomorrow morning to test results.

Hopefully you were right that this six engine RD290 requires different PIDs vs QAV quadcopter.

If not I will have to research the possibility of buying a high quality external barometer for the revolution. Would this be an option too? Please let me know.

BTW, what does PID stand for?

[Mateusz]

Thanks for this advice, I have made the changes and will try flying my drone in the park tomorrow morning to test results.

Hopefully you were right that this six engine RD290 requires different PIDs vs QAV quadcopter.

If not I will have to research the possibility of buying a high quality external barometer for the revolution. Would this be an option too? Please let me know.

BTW, what does PID stand for?

PIDs is a controller and stands for Proportional Derivative Integral. You can search literature on PIDs controllers, but in general those are loops that you feed with input variable and they control something for example motors to reach desired value as quickly as possible without overshooting (really vague explanation, but I hope it makes it clear what's the purpose). Motors must affect input which could be sensor measurement and the feedback loop is closed. So for Altitude it is used to maintain height, for Stabilization it is used to maintain level.

As for the barometer, unless something new appeared on the market, the one used in Revolution is high precision and best for the purpose on the market. You will not be able to find anything better. It's just technological limitation.

[darkdave]

I adjusted the PIDs and altitude Vario works fine now but Altitude Hold still fluctuates.

[TheOtherCliff]

When the throttle stick is in the center, +-10% (the center 1/5th of travel) then ALtitudeVario becomes exactly ALtitudeHold.

There is a PID for vertical Velocity that is used when AV is outside the throttle center deadband.  There is a P that is additionally used for ALtitude/Position when in AH.  These are cascaded PIDs exactly like the stabilization Inner and Outer loop PID and PI used by ATtitude mode.

I have a weak 500 quad with Revo or Sparky2 that tunes AV/AH fairly well.  I have a weak (2s) or strong (3s) 330 quad with Nano that I can't seem to be able to tune for really tight lock.  Others with 250 class quads are also having problems with getting a good lock.  I am coding sonar support and it needs a tight lock to follow the ground accurately.  I'm investigating this and hope to get it much more solid.

[nacholibre]

thats how mine does. really cant use the gps functions. always going back and forth with no baro or mag signal and fly's like a drunk mosquito in  gps mode. if i disable the gps and fly in comp mode i have very few problems at all. if i want to fly that model i always have to hook it to the laptop and go through the whole calibration thing every time. it take so long i just don't fly it much. and never in gps mode. thats why i bought it. and ive never once got to use a gps mode. which i must say makes me mad put as nice as i can say it. how do i know who to get an official one from. mine i bought on amazon but it came from so Chinese company so who knows? it cost me alot more than the cc3ds i had been buying and more than the skyline naz 32 i bought so i thought this one has to be good. who are the reputable sellers?

[hugges]

Hi i have just received  a replacement revolution  from banggood i have included a screen shot
can some one tell me if the baro is good or bad
Its not fitted into the quodcopter  yet just plugged into pc
any help