Disabling the servo/throttle cut when using X-Port

[rotordemon]

Title says all..

I am looking for a way to disable the Throttle / Servo cutout when the X-port button is depressed. Reason being is that I am looking to use the X port for another function using a servo or a stepper motor.

Any input would be greatly appreciated.

[gnascher]

Unfortunately, there is no way to do this, as it is a function of how the circuits are designed.

If you were an electrical engineer, and had the proper equipment, you MAY be able to do something to the circuit board (wild speculation here...) of the tx, rx or both ... but there is no simple setting or jumper that you can change to make it behave differently when the X-port button is pressed.

[surjer]

what happens when the xport button is pressed?

[rotordemon]

surjer said:

what happens when the xport button is pressed?

It temporarily shuts down the transmitter so the plane cuts the motor and all the surfaces back to neutral til you release the button. I previously thought it was another channel but I was incorrect.

[joeflyer]

So, I thought my xport stuff was just defective??? You're saying the button "Should" cut all control off? Why would I want that?

I thought pushing the button would activate my xport...which it doesn't The only way I've been able to make my drop module work is to turn off my TX mid-flight -- yeah, that's not good... but, it works.

I guess it's good to know, this is how they're supposed to behave, but it makes no sense to me

[cjg]

joeflyer said:

So, I thought my xport stuff was just defective??? You're saying the button "Should" cut all control off? Why would I want that?

I thought pushing the button would activate my xport...which it doesn't The only way I've been able to make my drop module work is to turn off my TX mid-flight -- yeah, that's not good... but, it works.

I guess it's good to know, this is how they're supposed to behave, but it makes no sense to me

My drop module is like yours. The button stops the motor and control, but doesn't drop, even when I hold it for 30 seconds. I have to switch the transmitter off to get it to drop. Horizon replaced the drop module and the receiver, still doesn't work. The cable is fine, all 4 pins show a closed circuit with an ohm meter.

Pin #4 reads constact 10.5 or so volts.
Pin #2 reads about .2 when the black button is pressed, about .5 volts or so when the transmitter is turned off.
Pin #3 reads zero volts

Any ideas on what they are supposed to read?

[joeflyer]

I wish I knew? But, I never took any electronics classes...I know enough to use an ohm meter, like you, and I think if I remember (it's been awhile since I checked), I believe I saw similar readings...but, I didn't know what to make of it.

The HobbyZone people offered to checkout and/or replace my drop module, but that didn't make sense...because without the drop module involved, pushing the button on the TX still shuts off everything on the plane, and that just makes no sense to me...it also proves there's nothing wrong with the drop module (not much can go wrong with it, it's just an electro magnet) so, pushing the button on the TX should only affect the xport not the whole plane...right?)

Anyway, like you, I'm hoping someone smarter about electronics will read this and give me/us the answer...when I tried to figure it out on my own I fried my original receiver and had to buy a new one

[grimreaper]

Mine for shure also cuts out everything, when I press the x-port button on my Tx. Which in my opinion is really stupid!

[davemac2]

It cuts out everything because pressing that button actually compresses the PPM signal in time sent by the TX to the receiver and makes it undecodable to the RX. So in effect, the RX thinks it has lost the signal. However, that compressed signal when examined by the drop module (ie. it is also fed to the drop module thru that 4 pin connector) appears to have a larger distinct DC voltage component when appropriately RC filtered than the normal valid PPM signal when then RX is receiving a valid signal. From examing HZ's method here, it appears as though this X-port feature was an afterthought add-on to an already standardized design.

For malfunctioning drop modules, turning off the TX eliminates the RX's receive signal completely, which the drop module interpretes after filtering as a zero or near-zero DC signal level and thus disables its holding magnet. Possible causes for the drop module to malfunction are:

1. the RX's PPM receiver signal level is out of spec and too low to provide sufficient DC to trigger the module. This may be caused by a weak battery pack or a damaged output from the RX's uController. Possible solution might be to use a 3.3K pullup resistor on the output.

2. The drop module circuitry that senses the higher DC voltage is out of spec or not well designed to account for signal level variations from the RX.


For either issue, it would imply that particular receiver/drop module pairings may not work whereas changing either may make it all work. Never-the-less, turning off and on the TX really has the same effect anyways due to the design of the drop module, so one could always change the button in the TX to a NC (normally closed) type and put it in series with the battery + lead in the TX.

dave mc

[cjg]

My Xport button never made my drop module work, event with a new drop module and receiver from the company. I did actually add a normally closed momentary contact switch to the power leads on my TX. Now all I do is touch that button, momentarily shuts off the radio, and module drops. Keeps me from fumbling for the slide switch.