Help needed with spektrum dx7

[Peter Budd]

Well, I've gone and blown my next six months allowance and bought a DX7 and 5000 receiver for my f16 but I have a problem.  I have bound the receiver to the transmitter and everything seems to work ok.  But sometimes when I switch on the LED flashes continously, but other times it stays lit without flashing.  Everything operates ok in both instances, but the servos go mad as it starts up and then flashes.  Why does it do this.  I thought once it was bound the LED should stay on and not flash.  Also should I still switch transmitter on first before receiver as with 35 Meg

 Cheers for any help

Pete

[Brian Lambert]

Well no one else has answered so I will give it a go, I don't have experience with the ar5000 receiver but with the other receivers if you turn off the receiver but not the transmitter, when you turn the receiver back on the LEDS flash once a second to indicate a power loss. And yes TX on first, I give mine about 5 seconds and then turn on the RX, turn of the RX first. Don't forget to re-bind after you have finished setting up the TX to reset the fail-safe settings in the RX.

HTH Brian

[winchweight]

As he says. The flashing is because you've had a power interupt at the model, but haven't had a corresponding one on the tx. The rx has interpreted this as an erroroneous power interuption. So when you switch off the model, switch off the tx too. Then power up the tx and then the model. After a few secs the light should come on steady.

I have a similar problem of the servos glitching during the intiial lock on phase. Dunno why, just does it, then everything is normal once the rx and tx say hello.

[Peter Budd]

Ah, I have been setting up the radio and have just left the transmitter on all the time on the table, just switching the receiver on and off when making mechanical adjustments. Can't see this makes a diiference though.  What you are saying is that if I switch the reciever off I must switch the transmitter off aswell and then switch it back on before powering the receiver??

[Peter Budd]

Shaun I posted this the same time you did in reply to Rusper, hence it seems I am repeating the obvious.  I hadn't read your post then.  Thanks both of you.  Seems a faff though having to switch tx off each time, and no mention of it in the manual!

[Tim Mackey]

I concur.

[Peter Miller]

I had the same thing with my D7000 Rx. I didn't know the cause but did a complete switch off every time it happened and got the solid light.

We live and learn.

[winchweight]

Peter, you don't have to switch off the tx every time, but if you don't you, will get the power interupt warning, that's all.

[Peter Budd]

and the servos going mental and past their limits until the receiver locks on.  That's my worry.

What I don't understand is how does the receiver know that the tx has been switched off and then back on again, since the tx was on when it was switched off and on when it was switched back on. If the reciever is switched off, how does it know the tx has been off and on again....if that all makes sense.

Pete

[Tim Mackey]

Peter Miller wrote (see)

I had the same thing with my D7000 Rx. I didn't know the cause but did a complete switch off every time it happened and got the solid light.

We live and learn.

havent heard of the D7000 Peter...is this a new Spekky Rx that has escaped my attention? please tell all.

[Tim Mackey]

Peter Budd wrote (see)

and the servos going mental and past their limits until the receiver locks on. That's my worry.

What I don't understand is how does the receiver know that the tx has been switched off and then back on again, since the tx was on when it was switched off and on when it was switched back on. If the reciever is switched off, how does it know the tx has been off and on again....if that all makes sense.

Pete

The servos should not move at all until the Rx locks onto the Tx signal - none of mine do -ever. The best method to use is to stick to the "normal" convention of TX on first, WAIT at least 10 seconds for the Tx to find and lock onto the 2 channels it needs THEN switch on the Rx - at which point the Rx will not output any commands to the servos until it too finds the Tx signal and GUID code, which should take around a couple of seconds maximum.

Memory. Both the tx and Rx memorise each others unique matching code ( set when they are bound ). Again switch off the Rx first, then the Tx. Powering down the Rx whilst it still sees the Tx codes sets it into "brown out mode" and if the Rx is then switched back on and still sees the Tx signal ( cos you didnt switch Tx off ) it flashes the led to signify brown out.

Switching it back on without the Tx signal present causes the Rx to be "idle"...awaiting the Tx code as it were, and therefore the led does not flash ( much the same as switching on Rx then Tx on initial booting)

Incidentally having the Tx too close to the Rx and /or the servos and cabling will often make the servos glitch as they are swamped by the overpowering output signal of the Tx. THis can also cause problems when binding. The recommendation is to be at least 2 feet away from the Rx when binding. 

[Peter Budd]

Thanks Timbo, a lot of that makes sense...I will bear it in mind when I have a play today.  It seems there are a new set of rules to abide by with 2.4

Pete

[Brian Lambert]

"The servos should not move at all until the Rx locks onto the Tx signal" Not sure that is true what about smart failsafe?

[Tim Mackey]

Failsafe only actually moves the throttle channel - and if the Rx is switched on without a Tx signal, throttle stays at idle. The other channels will not move, as failsafe on these Rx merely keeps the servos at "last known good" position.

[Peter Budd]

Well, everything seems ok...and had my first success with my F16 today.  No glitching as have had before and ballistic.

Thanks all

Pete

[Brian Lambert]

Timbo I don't think that is true, when I switch on my receiver the servos go to neutral, I think this is actually the position the controls  were in when it was bound to the TX, but I am not sure, I will have to do some tests.

[Brian Lambert]

To add. From the spektrum site

The Issue-With the transmitter turned on and the retract switch in the down position, when the receiver is switched on the retract servo momentarily drives to the retracted position (wheels up) for 2-5 seconds and then the servo is driven to the down position.

The Cause- Smart safe failsafe drives the servos to their preset failsafe positions for several seconds when the receiver is first turned on during the period that the receiver is making connection with the transmitter. (2-5 seconds) If the preset failsafe position for retracts is in the up position, when the receiver is first turned on the retracts will be driven to the up position until the receiver connect with the transmitter.

The Solution- Rebind the system with the retracts in the down position thus setting the failsafe position to up (not down).The when the system is first turned on the retract servo will be driven to the down position until the transmitter connects to the receiver.

[Tim Mackey]

Bad phraseolgy

What I meant to state was that FAILSAFE per se will not cause the servos to move ( other than the throttle -which will travel to the preset position determined in binding process )

As for the switching on part..... If the Rx is turned on first ( no Tx signal present ) the Rx will not move the servos, but when the Tx signal is then fixed, and received by the Rx the servos will travel to their "neutral positions ".

If the Tx is switched on first, and allowed to acquire and lock on to its 2 x required channels followed by the Rx, the servos will again simply travelk to their neutral position. How much they travel depends of course upon how far away they were from neutral before it was switched on.

Irrespective of the switch on sequence, servos glitching and chattering and swinging back and forth etc is something which does not happen - only in 35Mhz stuff when the rx is on and the tx is not.

Hope thats clearer. 

[andy harrold]

be careful with the failsafe.

i today bound my new dx6i its receiver. i then connected the esc. the esc said there was a problem with the throttle servo and it needed reversing. No problems, so i switch off the dx6i. at which point failsafe cuts in,

  throttle fully closed= max chat on motor!!!   Doh.   no blades on spinner so disaster averted, but be aware!

i think the spektrum instructions are poor in that they assume you have a receiver battery attached which is not always the case.

[Tim Mackey]

Whether you use a seperate battery or not, one should always "teach" the ESC the throttle throws as part of the initial setting up procedure - and this is always best done without a prop /fan fitted to the motor.

Also, I still think its best practice to continue the normal routine of ...

 SWITCHING OFF ? - model off first, then Tx.

 SWITCHING ON   ? - Tx on first, then model.

Glad you avoided any injury though Andy

[andy harrold]

i had trouble getting the bind process to work with it all connected so i removed the esc as part of the diagnosis

there is no ON-OFF switch in the circuit of the ESC so when i connect the lipo (deans connector) it cracks into life. should/can  i fit a switch?  the glider fuz has the fittingsalready there from the old esc. i think it will make it slightly safer for when someone has to recover the model on the rare occasion it hasnt landed at my feet!.  only joking!!

[Tim Mackey]

There is much discussion on the merits /problems of fitting isolation switches andy...personally, unless its really BIG stuff, i dont like em, preferring instead to completely unplug the battery as soon as she has landed. Once the Tx throws have been taught to the ESC, then inadvertantly trying to switch on ( in the correct order ) with the throttle stick anywahere except at "stop" will result in nothing happening as the ESC will automatically prevent the motor from turning.