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Dec 08, 2016, 04:40 AM
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Help!

FS-A8S help.


I'm having trouble with these receivers. I bought 4 of them and have had the same issue in all of them.

I've got them installed in 3 different racers. All direct soldered to Uart ports running 5 volts. All set in Ibus mode and they respond correctly on Betaflight receiver tab. Everything works....until you try to fly.
They basically cut out in a cyclic manner when the quads are under mid to high throttle. I have strapped them down and tried it on each of them and I can see the receiver light flicking on and off. This also has the effect of freezing the throttle and flight controls for half a second which is bad. It's like the receovers are having a brown out but they should be getting a nice clean 5v shared with the flight controller.

Any ideas?
Last edited by Sickocrow; Dec 08, 2016 at 04:45 AM.
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Dec 08, 2016, 10:17 PM
It does sound like there is voltage issues coming from somewhere to cause that kind of behavior. Do you have a multi-meter you can use to test? You say the issue happens when you try to fly so I would remove the blades from your quad and measure the voltages while increasing the throttle. It should at least narrow down the issue.
Dec 08, 2016, 11:30 PM
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Yeah I've tested it and it's receiving a happy 4.98v from the FC common 5v rail. I did some further tests Propless and got some weird results.


I refreshed my bind with a clean model in the i6s. Set it all up in Ibus in Betaflight. Everything moves in the receiver tab as it should when it's powered on but not armed. Arm it, and Airmode on, and it'll just sit there happy spinning. Now...in Airmode with no props on.

Yaw left, normal. Yaw right and the RX cuts out and twitches back on.
Roll left, normal. Roll right and RX cuts out and twitches back on.
Pitch back, normal. Pitch forward an the RX cuts out and twitches back on.
Throttle at idle, props spinning in airmode at low throttle. Throttle up past about 1150 command and the RX cuts out and twitches back on.

The blackbox registers the brief cutouts and the brief failsafe to zero throttle. We're talking like 0.5 seconds tops.
Dec 09, 2016, 05:09 AM
Quote:
Originally Posted by Sickocrow
Yeah I've tested it and it's receiving a happy 4.98v from the FC common 5v rail. I did some further tests Propless and got some weird results.


I refreshed my bind with a clean model in the i6s. Set it all up in Ibus in Betaflight. Everything moves in the receiver tab as it should when it's powered on but not armed. Arm it, and Airmode on, and it'll just sit there happy spinning. Now...in Airmode with no props on.

Yaw left, normal. Yaw right and the RX cuts out and twitches back on.
Roll left, normal. Roll right and RX cuts out and twitches back on.
Pitch back, normal. Pitch forward an the RX cuts out and twitches back on.
Throttle at idle, props spinning in airmode at low throttle. Throttle up past about 1150 command and the RX cuts out and twitches back on.

The blackbox registers the brief cutouts and the brief failsafe to zero throttle. We're talking like 0.5 seconds tops.
Ok, thanks for the info! I will have a chat to our dev team on monday to see if I can get you some answers.
Dec 09, 2016, 05:47 PM
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Thread OP
If it helps at all I'm using a TGY-i6s radio with version 0.01 firmware. It has worked just perfect with these receivers thus far;

FS ia6 in PWM mode
FS ia6b in PPM and ibus mode
TGY ia6c in sbus mode.

I have the new X6b receivers coming next week as well.

I'll also upload some black box logs as well.
Dec 11, 2016, 12:41 AM
Registered User
I have what seems like the exact same problem. Controls seem to "stick" for half a second when throttling up in flight.

FS-A8S receiver on a Kombini flight controller with the Turnigy Evolution transmitter. I measured 4.97v going to the receiver. This is within the listed voltage range of 4.0-8.4V on the product page. I do not have a way to measure the voltage in flight.

I have soldered a 22uf capacitor across the 5v rail and I'll report back next time I fly.
Dec 11, 2016, 06:34 AM
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Thread OP
Quote:
Originally Posted by RocketLawnchair
I have what seems like the exact same problem. Controls seem to "stick" for half a second when throttling up in flight.

FS-A8S receiver on a Kombini flight controller with the Turnigy Evolution transmitter. I measured 4.97v going to the receiver. This is within the listed voltage range of 4.0-8.4V on the product page. I do not have a way to measure the voltage in flight.

I have soldered a 22uf capacitor across the 5v rail and I'll report back next time I fly.
Well at least now I'm know not losing my marbles. Cheers. All 3 quads I had tested the A8S on had Caps on the battery lead.

I have outfitted 2 of my 3 quads last night with ia6b receivers in Ibus mode, and used them at a race meet today. Flew 15 packs with not a single problem. So it's not the ibus protocol, but something VERY odd with these little receivers. I can report that the A8S seems to work fine in PPM mode. I switched it over and tried in my 3rd non-race quad and that seem okay.
Dec 11, 2016, 08:13 PM
Registered User
I tested the capacitor today and it changed nothing. Same sticking/dropout glitches.

I had a FrSky X4R-SB previously and it worked though I did notice occasional "frame skips" or single "stutters". Possibly the setup on this quad is noisy. Video is really clean though o.0

I have an iA6C on my other quad and it works perfectly in IBUS mode. I have ordered some X6B receivers as I like that form factor better anyway.

*edit*

Thinking about it more after you mentioned that PPM worked - maybe the problem is how the flight controller is interpreting the serial input from the A8S.

FlySkyRC - maybe ask the dev team to compare the IBUS output of the A8S and a different IBUS capable receiver while hooked up to a flight controller. Also check what happens to the IBUS(serial) signal while the motors spin up.
Last edited by RocketLawnchair; Dec 11, 2016 at 08:20 PM.
Dec 14, 2016, 07:13 AM
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Thread OP

Blackbox log for checking


This is my non racer I took some Blackbox logs (file below) to show the receiver cutting out. This Quad only cuts out on mid and above throttle, and the controls otherwise seem normal.

Also, another RCgroup user has issues as well, here is a video he took and this replicates what my other 2 quads are doing with the A8S;

FlySky FS-A8S receiver brown out issue (1 min 6 sec)
Last edited by Sickocrow; Dec 14, 2016 at 05:48 PM.
Dec 14, 2016, 02:12 PM
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ischlfpv's Avatar
Here exactly the same problem. I bought 2 FS-A8S from Banggood and all two the same. My first flight ended up with a crash ... (Transmitter is the Evolution)
Dec 14, 2016, 05:45 PM
Registered User
FlySkyRC, please also pass to your dev team another issue that everybody is having with this receiver:
Once powered on, FS-A8S sets default communication protocol IBUS. You can change IBUS to the SBUS by pressing bind button for 2 seconds. But if you power off/on this receiver it does not remmember this setting and defaults to IBUS again. This makes no use of SBUS protocol as this setting is not saved. Some users are struggling with this issue and complaining about this issue. It could be easily fixed in firmware.

(Small tip: next time send some samples to the testers/reviewers prior the manufacturing process or at least before starting to sell. This will minimize the chances of some seriuos FW or HW issues )
Dec 14, 2016, 05:52 PM
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I'm waiting on the outcome from the Flysky dev team as to what to do with these. I'll try using them in PPM some more for now. I haven't tested that thoroughly either
Dec 14, 2016, 07:18 PM
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Quote:
Originally Posted by Sickocrow
... another RCgroup user has issues as well, here is a video he took and this replicates what my other 2 quads are doing with the A8S;

https://www.youtube.com/watch?v=jApp...tRPVz7w4LrfCQg
Hello FLYSKY!!! So happy to see you guys paying attention to "us". ;-) Says a LOT about a company. This is my video above, which I made after reading Sickocrow's post in the other thread. Now we have a visual of what's going on, and hope it's helpful.

Quote:
Originally Posted by montis
FlySkyRC, please also pass to your dev team another issue that everybody is having with this receiver:
Once powered on, FS-A8S sets default communication protocol IBUS. You can change IBUS to the SBUS by pressing bind button for 2 seconds. But if you power off/on this receiver it does not remmember this setting and defaults to IBUS again. This makes no use of SBUS protocol as this setting is not saved. Some users are struggling with this issue and complaining about this issue. It could be easily fixed in firmware.

(Small tip: next time send some samples to the testers/reviewers prior the manufacturing process or at least before starting to sell. This will minimize the chances of some seriuos FW or HW issues )
Yes, I think only some of us have the brown-out issue, and I'm thinking it's a bad batch. First run seems to have been fine, or at least without THIS issue, but then the bulk that went to BG - either all or some of it has the brown-out issue.

@montis, they did actually use testers, but probably not that many, and not sure what kind feedback they go, as the problem with not saving SBUS mode came out the other end during production still. I think maybe most if not all just put it in their rig and flew it. Done. Like me, most thought the biggest concern was range. FLYSKY is known to make quality products, or at least it has been my experience, so really wasn't expecting these issues. I bought 5 of these RXes when I got my Evo TX because I know from experience that the only other RXes that are out for them are the big official ones, and some "3rd party" ones that only do PPM or just suck. I haven't used PPM in a really long time now, having moved to SBUS and DSMX for their MUCH faster and reliable response, and I'm not about to go back for any reason.

@FLYSKY, as people who basically got screwed on this deal and still are trying to help you resolve it, I hope you will be awesome enough to send us replacements if there isn't something we can fix ourselves (without buying components). I could go through banggood, but I'm pretty sure all of what they're selling now will have the same issue.

Thanks for listening, and your help.
Dec 14, 2016, 08:25 PM
Quote:
Originally Posted by MrSatoV
Hello FLYSKY!!! So happy to see you guys paying attention to "us". ;-) Says a LOT about a company. This is my video above, which I made after reading Sickocrow's post in the other thread. Now we have a visual of what's going on, and hope it's helpful.



Yes, I think only some of us have the brown-out issue, and I'm thinking it's a bad batch. First run seems to have been fine, or at least without THIS issue, but then the bulk that went to BG - either all or some of it has the brown-out issue.

@montis, they did actually use testers, but probably not that many, and not sure what kind feedback they go, as the problem with not saving SBUS mode came out the other end during production still. I think maybe most if not all just put it in their rig and flew it. Done. Like me, most thought the biggest concern was range. FLYSKY is known to make quality products, or at least it has been my experience, so really wasn't expecting these issues. I bought 5 of these RXes when I got my Evo TX because I know from experience that the only other RXes that are out for them are the big official ones, and some "3rd party" ones that only do PPM or just suck. I haven't used PPM in a really long time now, having moved to SBUS and DSMX for their MUCH faster and reliable response, and I'm not about to go back for any reason.

@FLYSKY, as people who basically got screwed on this deal and still are trying to help you resolve it, I hope you will be awesome enough to send us replacements if there isn't something we can fix ourselves (without buying components). I could go through banggood, but I'm pretty sure all of what they're selling now will have the same issue.

Thanks for listening, and your help.

Thanks! You have no idea how helpful it is to see the issue. Right it appears this is a known issue and I am talking to people on what you guys need to do. I will have a reply in a few hours as everyone is in meetings and the like.

Without customers there would be no Flysky, so thank you all for supporting us. We will get a solution to this issue asap.
Last edited by FlySkyRC; Dec 15, 2016 at 12:42 AM.
Dec 15, 2016, 02:33 AM
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Thread OP
I'm sorry to report that flying in PPM with this RX is not a good experience. There is a serious amount of latency, more than normal for PPM, and controls are not very responsive. Started having control drop offs at 40-50m away any complete fail-safe at less than 70m. This is in an RF quiet area.
Flew in the same park minutes later with a Quad equipped with an ia6b with zero issues.


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