Micro Motor Community

Binding FS-i6 to OverSky SciSky Micro F3


STEM teacher trying to build DIY micro-drones with students. Motors and battery soldered (and working), firmware flashed (SPRACING3EVO), but unable to bind FC to TX. At my wits’ end. Please help!


Have you selected the correct Uart setup in BF settings? FlySky is F3-C rather than F3-AB. I am not all that good with SciSky and various protocols but for an FS-i6 which is flysky Uart 2 Serial Rx should not be selected whereas with type AB it is and that’s for Dsmx/2 FrSky and SBUS Rx. The more you can tell about the procedure you’ve gone through and specifically what happens the better chance someone can help you with this. Very cool this is for STEM project at school so I want to try and help if I can. Also have you gone through the Scisky setup instructions? There is a pdf you can download that tells specifically the procedure from flashing to binding. Just in case you haven’t this is a link for that http://www.overskyrc.com/index.php?main_page=fillib&file_path=F3FCfirmware%20FlashingGuide.pdf


Thanks, @madman1412!

I did come across the PDF you linked, and set up BF as directed for an FC-3. I received some helpful information from r/multicopterbuilds when I first reached out for help concerning the build as a whole, but I’ve not heard from anyone regarding the binding issues specifically.

This project is based off punkkills’ Instructable. I would link directly, but new member restrictions prohibit more than one link, but it can be found in the linked subreddit discussion above. I had to go a different route with the FC as the one suggested was no longer available. The binding process is described as:

Binding Your Radio

With basic configuration of Cleanflight out of the way, it is time to bind to a radio. When the Scisky is first powered up, the red LED flashes slowly indicating that it is looking for a bound radio. If after 10 seconds, it does not find a radio, it enters bind mode and the red LED flashes quickly.

  1. Connect the Scisky to USB.
  2. Wait 10 seconds for the red LED to begin flashing quickly.
  3. Put your radio into bind mode. Consult the instructions for your radio if you need help with this. If you are having trouble binding, try holding the antenna of your radio very close to the Scisky antenna, like almost touching.
  4. When binding is successful, the red LED on the Scisky will turn sold.

Receiver Tab

With the radio bound, it is time to setup the receiver. Connect to the Scisky in the Configurator and head over to the Receiver tab.

To no avail.

I read that the OverSky F3 Micro does not support AFHDS 2A, just AFHDS. I went ahead and disabled 2A on the FS-i6, but again, nothing.

My current settings are as follows:

I would love and greatly appreciate any assistance the community can offer, even if it is, “Hey, idiot. That Tx and Rx are not compatible, you need (blank) instead.”



That AFHDS is the correct protocol to have selected in the radio. Most of what I can find online was people that were trying to use the AFHDS 2A. Since you do have the correct one selected in the radio and the FC is still not binding I wonder if it is the correct Rx on the FC. On the side with the STM there should be 3 other chips on the board. Those are all RF chips that do the various protocols. I believe the smallest one is the chip that controls FlySky protocol. Should be stamped R5F10278A and is a 24pin QFN package, QFN means there are no pins on the chip. If the smaller chip is not there then it will not work for AFHDS. I’ll keep digging around and see if I can scare up someone with more experience with flysky and Actually I was looking at an older board I have here someone sent me for the parts. The RF chip to look for should be 20 pin and say A7105 that is the AFHDS chip.


I’ve flashed about 5 boards, and they all have only shown 3 chips (if the chips are the ports), except for one. One of the boards actually showed more than 3 ports (chips?) but I thought maybe I had botched the firmware flash some how. I’ll see if I can find that board again and send in some shots and try to bind it on the other ports.

Picture of front and back PCB of the actual board I am working on. I see the STM chip you referenced, but I do not see any QFNs.


As flysky is most used in SerialRX configuration try setting SerialRX and ibus in the configurator. The scisky boards don’t have a fantastic reputation since the F1 days tbh, I’d recommend almost any other on the market over that one.
The chips Madman asked about are physical, black chips on the board, ports are down to the available resources on the main mcu, the F3 in this case.


Thank you for clarifying, @Chaotix. I thought maybe the chips @madman1412 referenced were represented as ports in BF. So much to learn!

I did try to set SerialRX on UART1, but it would never save and reboot the board. It sounded like the board was disconnected from the computer, but BF would still simulate it as being connected. When I attempted to change over to another settings tab it would just show the loading animation but never actually do anything. I would then manually disconnect, reconnect, but nothing saved properly.

Should I be trying to utilize a different port than UART1?


To further muddy the waters (or perhaps clear them) I did purchase some independent RXs - Usmile FS82 2.4G when placing the order for the other parts. When I got them in I hadn’t realized the FC had an onboard RX, so I just shoved the FS82s in a box.

I have attempted to bind one with the FS-i6, but I didn’t spend too much time on mostly because I don’t know how to connect the FS82 to the SciSky F3.

Could that potentially be the work around, and if so what types of settings do I need to adjust in BF, etc.?


So the chip I was talking about that should be on the FC for the Flysky protocol does not appear to be on the board. When I look up this board and go to the only place I am seeming to find them for sale it takes me to GetFpv. The picture there also shows the exact same FC you have with only the two RF chips that do the other protocols which is that CYRF6936 and the cc2500 both below the STM and they are what is known as the QFN package which is a chip that has no pins on it lke the STM. Sad part about the Scisky is that it never had good documentation on how to make them work. I have dug around looking for the documentation on the 4 pin header that is opposite end of the USB socket and have not found any info. That would be the connection to use an external Rx but I am not sure how it is wired. There would be at least 3 connections, power, ground and signal. If you have a multimeter you should be able to test the pins to find the ground and power by testing between various points on the FC but I may be getting a little technical with that, grnd would be easy since that you can test right to gnd at the power in, the supply voltage cames from a voltage regulator and I do not know if this would be 3.3v or 5v some Rx only work wirth one or the other and giving one 5v that operates at 3.3v could damage the Rx. The FS82 uses 5v so that shouldnt be a worry and the voltage from the USB when plugged in should go directly to one of the pins on that 4 pin header. If you look at the pins of the usb where they contact the board so the open end is point away, pin 1 is on the left and that is where the 5v is, pin 5 all the way to the right is ground and typically the outer case of the USB is ground. That will get you ground and Voltage in and one of the other two pins is the signal which is coming from one of the pins on the Rx directly. If there is any chance that you could get your hands on a different Tx to try with this like a FrySky, Futaba, spektrum this could confirm what I think is wrong and that is that it does not have the A7105 RF chip for that protocol. Last thing, have you contacted the vendor to inquire about any documentation on the FC?
Looking at some of the scisky that I have which are F3 it looks like pin 1 of that connector is far left in the picture and that should be Rx, then pin 4 all the way to the right is ground and pin 3 should be 5v. Pin 2 is Tx and I think is for hooking up a video transmitter.


So what I hear you saying is, “Get different FCs”. I’m certainly not afraid to dabble in the finer soldering arena, but on 50 FCs total seems a little daunting.

I do really appreciate your assistance, especially knowing you took time to do some detailed research.

What comparable FCs would you recommend that would be compatible with the FS-i6?


Oh crap, I didn’t realize you had that many. Very sorry, that is a real bummer. Do you also have the other gear needed for this such as motors and frames? Just asking so I can make a decent recommendation that will work with what you have. What @Chaotix suggest is a good idea. That is a lot of dough.


Post a clear close up pick of the top of the board before we go any further. I think we should establish exactly what you’ve got to play with before advising further. So you have 50 already?


Haha, yeah, I tend to go off the deep end and really thought I’d properly researched all the parts. I have definitely learned that SciSkys should be avoided.

Here’s a Google Doc with parts and links.



I do belive all those connections from the 4 pin header are available on the two dupont style headers seen on the board @Chaotix from following the traces of some of the junk ones I have.
Yeah the header on the right has the connections. I just opened the google doc.
Also if you follow the link to Getfpv for that FC the header says dsmx/dsm2 but down below in the description which I am sure is wrong says it can do the flysky bit note that that requires the A7105 RF chip which is not on these boards.

this is one of the junk boards I have that have the 3rd chip although this one is not the A7105 chip but probably a knock off.


Thanks for pointing me to this thread, @madman1412!
I love helping micro quad school projects :smiley:

@ctb0045, let me ask the ask the question: how many of those FS-i6 did you buy?


I thought you might be interested @Benedikt :grin: not sure why my profile is split between two in Discord. @ctb0045 is also on reddit if you didn’t catch that in the thread here.


Hey @Benedikt,

Thank you for reaching out. I bought 15 FS-i6s and approx. 50 SciSky F3s. I believe the return window has closed, but I can ask our administrative assistant. Are you thinking I should return them and get a different radio?

Thank you, @madman1412 for the shout out. Winter Break and back to school chaos prevented me from getting back on here until today!


No problem. Benedikt is how I got here haha. He’s a pretty busy guy so I will let him know there is a reply here if he doesn’t see it. The sad part is the listing for those Scisky was pretty confusing as in the description it makes it sound as though all these were capable of the various protocols but the main description said DSMX/DSM2. Also it’s kinda bad business I think to sell someone 50 FC and 15 Tx knowing that they are not compatible or at least they should know that they wouldn’t work together.


To be fair, I bought the Tx and Rx from two different vendors - cost savings being a major contributing factor.