Review: XRacer F3 Flight Controller – FPVModel

X-Racer F303 Flight controller is built with the next generation F3 processor, which allows more configuration options and great for multirotors FPV racing. More importantly, it doesn’t cost an arm and a leg!

Get your X-Racer F303 FC from FPVModel.

F3 flight controllers have been around for a while now, they are great choice for high performance racing quadcopters, and more capable than the F1 FC’s (e.g. Naze32 and CC3D). I didn’t make the switch simply because of the expensive price and availability. (a more detail article on the differences of F1 and F3 flight controllers)

Quick Look at the X-Racer F3

This board has a clean design as it’s for Acro racing. There isn’t any unnecessary stuff like barometer or compass.

On the top of the XRacer F3 board, you can see the F3 processor, Gyro and Accelerometer sensors.

The pins on top are the 8 motor pins. On the right there are 2 UART serial ports (UART1 and 2).

Down below there are the Radio pins. Similar to the Naze32 it supports PWM radio, but if you are using PPM or SBUS you will be able to use those spare pins to run things such as softserial.

Only thing I don’t like is the dedicated SBUS port which is also the UART3 port. You can see RX is available and TX is missing, that means if you are running PPM, you won’t be able to use UART3 for things like Blackbox or OSD where TX is needed. (You can still use UART1 and 2 though)

XRacer F303 flight controller top

On the bottom of the board, there is a 16MB flash memory chip, should be more enough for PID tuning with blackbox.

There are also solder pads for your buzzer. Maybe it’s due to space limitation that they can’t provide header pin out design for it. But it’s not the end of the world, I think I can still solder header pins on the pads parallel to the board. Or just solder the buzzer wires directly to it.

XRacer F303 flight controller bottom

The board is compatible with Cleanflight and Betaflight, and actually uses the same firmware hex file as the SPRacingF3.

I am building a new mini quad soon, so I will be using this F3 board with SBUS (the first time!).

XRacer F303 flight controller connectors header pins

Advantages of this F3 Flight Controller

To sum up, so far I feel positive about this FC. But saying that I still need to do some more testing on it. Here are the good things about the XRacer F3.

  • Affordable
  • 3 UART’s (only 2 on F1)
  • Better processor than F1
  • All connections using header pins, no more weak, plastic mini JST connectors!
  • Built-in inverter for SBUS
  • Push button for shorting bootloader, no more soldering required.
  • 16MB of flash memory for Blackbox! (Tornado has 0MB, SPRacing F3 has 8MB)

XRacer F303 flight controller

Things that can be improved

  • Change the dedicated SBUS port to normal UART3, and provide both TX and RX pins
  • There is no VBAT Pins?! How can I monitor voltage level? Might have to rely on my MinimOSD then? They should really bring VBAT back
  • Need better documentation, like how to wire things up, how to configure telemetry etc… But that seems to be common with most FC these days, maybe I will write some documents up when I use it more

XRacer F303 flight controller f3 sbus

Update 30/Jan/2016

A couple of issues I encountered with this board when I first using it.

First, the Buzzer solder pads were extremely easy to peel off. Maybe it’s my own fault, I was trying to solder 2 header pins on it, to plug in my buzzer, the pads just got ripped from the board when I pushed the buzzer connector into the pins.


Second problem was the board stopped getting power from the USB port. The board was only connected to RX and USB cable, and I was fiddling with cleanflight configurator, and few minutes later the LEDs on the board just went off, and it disconnected from CF configurator. I can still see the COM port but cannot connect.

However it still works when powered from motor pins 5V. I can still connect to the CF configurator when powered with motor pins. So that suggest TX/RX/GND of the USB port are still working, just the 5V isn’t. Some people suggest it might be the diode connecting to the USB 5V.

Both problems have been reported to FPVModel and they said they will look into them. For now I cannot use this board on my build due to these problems.

Update (27/Feb/2016) – I was sent a replacement and finally I could test this board. Here is the maiden video. Flight performance is solid! With some more tuning it will be great!

Update (21/Mar/2016): After giving FPVModel my feedback, they fixed many of the problems and released a V2. For more detail check out this post.

31 thoughts on “Review: XRacer F3 Flight Controller – FPVModel

  1. 1tC

    Just busted my usb connector on the x-racer v3 board. Tried resoldering > didn’t work > smoke! So need another solution….

    Is it possible to set up UART-to-USB adapter? And if so, how?

  2. Machine Vision

    Thanks for sharing this nice article. and I wish to visit again on your blog. keep sharing with your work.

  3. Russell Gilder

    Hi Oscar
    Where you able to get the buzzer up and running after the pads came off? I have the same issue and I’m not sure if my buzzer is not working because the pads came off or if its another issue. Also, Cant get LED running. V-bat works fine though.

    1. Rob

      I am also curious if anyone found a solution when the buzzer pads are gone. I just spend 45 min searching my quad and it would be so much easier with a buzzer!

  4. David Chong

    Hi Oscar

    I am using a OrangeRx PPM receiver – where do I connect the single cable from my PPM receiver to this X-Racer board?
    Do I connect my PPM cable to RC Input CH1?

  5. michael

    thanks for your review. do you already have an example for wiring it found or ready to show?
    i’m just starting to make my 180er with the x-racer f3 and can’t figure out how to connect all the stuff… (and yes, i’m a beginner and this is just my second mini quad).

    1. Oscar Post author

      which device are you problem with connection?
      it will take a long time drawing a good diagram… quick and bad diagram will only cause more confusions…

  6. Crash override.

    Hey man, I’m just writing to say that mine aswell has stopped working with the usb 5v, totally dead I hope they fix this problem as I was really looking forward to trying this board out. But only got to setup testing no flying :(

  7. Julez

    Hi Oscar,
    first thanks for your nice blog! Now to my problem: I have bought the xracer f303, its working fine yet but i want to flash betaflieght on it, but the the refuses to flash any Software (“No response form bootloader, programming: FAILED”). I also tried it with shortend pins. If i want to connect it to cleanflight it works fine, even if i dont get a radio signal yet but i think this is another issue.

    Do you or anyone else have an ideo how to get my board flashed?

    Greetings from Germany

      1. Oscar Post author

        Glad you found the solution!

        lastly, i would really appreciate it if you could post your questions on the forum in the future: … I don’t want to miss your comment, because I only check my blog comments once a week, but I use the forum daily!

    1. Oscar Post author

      one of the motor or RX 5V/GND pins…
      lastly… i would really appreciate it if you could post your questions on the forum: … I only check my blog comments once a week, but I use the forum everyday!

  8. Lilo

    We want F3 boards with gyro connected to the SPI bus instead to the i2C bus !

    F3 boards with i2C is a waste of money and effort developing and means buying twice.

    An alternative is to use Raceflight with F4 boards, they have lot of power ready for being released since the raceflight (betaflight/cleanflight fork) is being developed further together with multishot firmware for escs.

  9. Dexter

    Alvin: I connected a Spektum Satellite to the SBUS-GND-3,3v and it is powered by USB.

    But I cant figure out how to connect an adressable LED Strip like the Matek WS2812B. This works with all other controllers on RX Port 5 or 7 but no luck on the X-Racer. Any idea?

    1. Ryan Sheridan

      Have you had any luck with this? I am still having issues getting it to work. I could occasionally get the leds to light up using RX port 7, but nothing consistent. Curious if anyone knows anything else.

  10. Relic

    Hi Oscar,

    To solve the problem of no VBAT, there is a simple way to get telemetry of flight battery voltage that some pilots consider superior to VBAT anyway, because it’s simple, works, and the voltage reading updates more quickly. And it doesn’t involve the FC whatsoever.

    FrSky D4R-II and X4R both have one pin in the 4-pin telemetry input dedicated to an analog input, e.g. voltage (it’s called AIN and is not in the same place on both receivers so beware of that). To reduce your voltage to a range that this pin expects, you can make a tiny “voltage divider” out of a wire and 2 resistors. Or you can simply buy the FrSky one (it’s called FLVS-01) pre-made for $3, but it’s pretty bulky (I bought one).

    The telemetry value doesn’t come in as “Cel” or “Cels” anymore, but A2 (standing for analog telemetry value #2: I think A1 is used for the 5V supply to the Rx itself) and you can configure your Taranis to display that and trigger warnings.

    The new KISS FC has the same issue (no VBAT in the v1.0 version) so the topic came up in that thread. FinalGlide was very helpful and posted links and even a pic of one he made:

    The FrSky FBVS-01: ready to go for the D4R-II, but you need to change the pin order to use it on the X4R:

    This topic might warrant a separate blog post for you Oscar :) Thanks for your great service to the community! :D

    1. SprazzZ

      O gosh – this is something I should have figured out myself… would have saved me from spending hours to get telemetry working besides a minimosd on softserial :) Only downside then is that you won´t have it on the OSD though or is there also a solution to send it back to the FC like RSSI ?

    2. hoggdoc

      Hi Relic,

      Of course this solution doesn’t work if you aren’t using a FrSky TX & RX. This is just another reason to jump onto the Taranis Bandwagon folks, the flexibility not equalled anywhere else.

  11. zaniix

    Hi Oscar
    I would love to see you compare the X-Racer F3 to the Seriously Dodo F3 board. You can connect Battery power direct to the dodo and it pulls VBATT from that same connection. I plan to use the Dodo when I eventually build my first quad.

    and thank you for all you do, I can not say enough how much I enjoy your site and have learned from it.

  12. Alvin

    does the usb pass through voltage to power the RX like the new Naze32 rev 6 board? I found that this conflicts with trying to do 1 wire esc calibration through blheli. Also, does it connect to the ez-gui app if you use an SBUS rx? I’m not happy with the Naze rev 6 board and would like to find a replacement.

  13. neclovek

    What about the CC3Ds big advantage with the MPU6000 and the SPI interface? No other boards doesnt seem to use it…Or maybe those ultrafast looptimes arent needed at all?

  14. marco

    on FB fpmodel says ” No vBat on the board but there is a way to use vbat via serial port” I was wondering how..

    1. Oscar Post author

      I have yet to test that and it’s not mentioned in the documentation, but i think it should and similar to SPRacingf3… any way i will report back when i have done that :)

    2. Lolo

      Hi!! Any news about Smart Port support and configuration on X Racer F3 latest versions?

      I need a new FC but the telemetry to my X4RSB is important to me…



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