Can't Arm Motors & Rapid Red/Green Led; Vibrations When Flying / Not All Motors Running When Armed; Can't Load Fc Update; Red - Yellow Flashing Led - WLtoys V303 Supplemental Information

Appendix 1: WLToys V303 Supplemental Information v18
Can't ARM motors & rapid
18.
red/green LED
Vibrations when flying /
19.
not all motors running
when Armed

Can't load FC update

20.

Red - Yellow flashing LED

21.
Green – Green - Yellow LED
22.

Calibrating ESCs

Symptoms requiring calibration of ESCs are as follows:

When arming rotors, not all blades are spinning at the same rate with throttle in neutral position

Excessive vibration of quad when in the air and having GPS Lock

After a crash when replacing a V303 ESC
Calibration requires the direct connection of the receiver throttle channel to each ESC to be calibrated. Since the V303
stock receiver uses S.bus and multiplexes all receiver channels on a single control line this is NOT possible on the V303
without using other components. I'll cover 3 ways that users have used done calibration and the additional components
required. In ALL cases the symptoms listed above were rectified, and overall flight characteristics were improved.
1. Replace Flight Controller with APM controller. There is no need to replace stock TX or Receiver. Connect APM
controller to RCVR, power and ESCs (all of them). The APM FC should bind just fine. Here is a
procedure. After calibration you can replug everything into the stock FC.
2. Replace TX and Receiver, and wire each ESC control wire directly to Throttle channel on RCVR (disconnect each
from V303 FC), and calibrate one at a time. You'll need to bind the TX and RCVR first. Here is a
calibrate. More details can be found here.
3. You can also use an Arduino to calibrate. The web article is here. Two critical numbers are needed to make the
sketch work on a V303. They are "MAX_SIGNAL" and "MIN_SIGNAL". Use 1800 (V303 Max µS) and 1200 (V303
Idle µS) respectively. You can calibrate all at the same time without any changes to your RCV, TX or FC.
4. Use cheap Servo Tester.
affordable means of calibration.

Replacing V303 Transmitter/Receiver

It is possible to use your own or a more sophisticated transmitter and receiver with the V303 while still using the WLToys
firmware and not losing any functionality. Your transmitter/receiver should be capable of at least 6 channels, but you'll
need 8 channels to control a gimbal if desired. While the WLToys receiver uses what appears to be SBus to connect a
11
Recalibrate the compass. Make sure the LED stays lite the whole
time you are rotating the quad. If it goes out do it again ... slowly
and precisely. Don't forget to save calibration.
Calibrate ESCs
There are two things you can try. 1) Try another computer ...
don't ask why but in many cases that has solved the problem. 2)
You may have an open wire or short between the belly USB and
the FC. Open up the quad, unplug USB cable at the Flight
Controller and cable directly to the Flight Controller.
Do the compass calibration
fine. You may see this after an unsuccessful compass calibration
or when power quad up after inserting battery.
Your compass has a problem and needs to be replaced or there
is a problem with compass wiring from the leg, to pcb to FC.
Here is an excellent video
successfully and everything will be
calibrating V303 ESCs using this method. This is this most
video showing the
video of how to
June-10-2015