Why does failsafe works? Multiwii 2.2 Turnigy 9x 8ch receive

[E_TE_T]

Why does failsafe works?

In the video you can see that the receiver stores the last values, when signal is lost. After one second the failsafe-funktion are activated.

I have the Turnigy 9x wit the turinigy 8Ch receiver 2.4 Ghz.
(original firmware)

5 Channels are connected to the board.
The board is a Crius MWC 2.0.

Here is the video that show it: http://www.youtube.com/watch?v=C9DrIlzB ... e=youtu.be

I set in the controller Setting->Fail Saf -> All Channel are now F/S 000%. (But all values before signal lost are stored)

here my code: (config.h)

#define FAILSAFE
#define FAILSAFE_DELAY 10
#define FAILSAFE_OFF_DELAY 50
#define FAILSAFE_THROTTLE (MINTHROTTLE + 200)

#define HK_MultiWii_SE_V2

GPS (Not connected) (This causes the I2C-errors)

#define I2C_GPS

#define MAG_DECLINIATION 1.18f


Multiwii.ino

(Because my controller generates cannel-values ​​in the range from 1055 to 1886)

// ******************
// rc functions
// ******************
#define MINCHECK 1100
#define MAXCHECK 1800

I can not explain now why the faisafe function starts?


E_T

[ardufriki]

Hi, finally I confirm your experiment. I dont know yet why it didnt work, but now does well. So I will remove my failsafe system at A6 pin.

It works with MW2.2 and w/o modifications on the rx. Good.

Next is to check if we can get a RSSI from this cheap rx.

[phenolic]

The RX does not keep all levels the same, it stops the signal completely(*) which in the old versions of MultiWii keep the last known pulse length (or something like that). The new version of MultiWii recognizes when there is no signal.

(*) On my RX it stops the signal on channels 1,2,3,6,7,8. Channels 4 and 5 still have pulses.

[E_TE_T]

Hi, finally I confirm your experiment. I dont know yet why it didnt work, but now does well. So I will remove my failsafe system at A6 pin.

It works with MW2.2 and w/o modifications on the rx. Good.

Next is to check if we can get a RSSI from this cheap rx.

Nice to read

E_T

[ardufriki]

Just for add some info about our rx, I attach some images of the MOD I made yesterday in order to get a RSSI signal for future use. I am planning to add a cheap FPV system and a Minim OSD card....

This is how I had before, with a wire from led area. I was triggering failsafe through A6 PIN:



And now, as Failsafe is triggered w/o any wire, I made the hack to get RSSI pin @ BIND pin from our 9x8c RX:





(sorry this thread is now a little off-topic)

[E_TE_T]

The RX does not keep all levels the same, it stops the signal completely(*) .

I have checked almost all the channels with a servo. All servos keep the last value.
(The receivers from different manufacturers behave differently here)
In my view, therefore, the software can not notice any loss of reception.

E_T

[phenolic]

I have checked almost all the channels with a servo. All servos keep the last value.
(The receivers from different manufacturers behave differently here)
In my view, therefore, the software can not notice any loss of reception.

Many servos will keep the last position if the PWM signal stops. You need to put the RX on an oscilloscope to see what it's actually sending. On a scope I can see my RX stops the PWM signal completely when it goes in to failsafe mode.

Although like you said, even within the same brand they can behave differently. However, testing with a servo is not conclusive and obviously MultiWii is detecting when the signal stops otherwise failsafe wouldn't work for you now.

[E_TE_T]

Ok I testet the signals with an oscilloscope.

The receiver stops the signal after signal loss.
This explain why it works.
Now I just have to figure out why it did not go with 2.1 multiwii.

E_T