[greggold]

Arming - or not arming - has been a lively debate that has led to progress: John Hopke has now produced a definitive guide.

https://www.youtube.com/watch?v=ARCfafma1rM

Some airplane flyers regard elrs as a drone rc system, with unnecessary features/requirements such as arming. They think plane flyers should stick to real airplane rc systems such as Spectrum and Futaba. Well they are right elrs is a drone system, that developed out of the need for fpv drones to maintain a rc signal with a decent rx signal to noise ratio at 20 km. The thing is, this elrs rc signal is also better than the legacy systems for flying line of sight planes at 200 m in noisy radio environments.

It is integral to elrs that channel 5 is for arming, it only has two positions, armed or not armed, unless you choose a special elrs tx mode which the video explains. However you do not need to worry about ch5 or special modes.

The video gives examples of calls for help, such as this: my betafpv or RM rx has 5 sets of pwm pins, I am using ch1 rud; ch2 ele; ch3 thr; ch4 left ail; ch5 right ail. Everything works except the right aileron, which only goes full up or full down, and nothing in between.

The solution is simple, but not intuitive for plane flyers who think 5 sets of pwm pins means 5 channels... but that is not true with elrs. You simply re-map the right aileron onto ch 6 in the mixer, leaving the R ail servo plugged into the 5th set of pwm pins (if this point or the next para confuses you please ask a club member who uses elrs for help).

Ch 5 remains empty in the mixer, but you assign a switch to arm or disarm ch 5. If you use a throttle cut/thr-active switch (which is always active when the plane is in the air), this switch is set in a special function to override ch5, so that whenever the thr is active, the plane is armed.

The bottom line: the video explains what being armed means, and reasons why you might want to be armed. Most plane flyers will want to use the elrs dynamic power feature and this works better if you are armed. A comment under the video by alanpaul1234 explains why dyn power works less well if you are not armed.

[caffeine]

I have a few logical switches which provide me with a safe starting mechanism for my planes:

   

Logical Switch 1: Is active when the throttle stick is less than -98 (i.e. it's at the minimum position)

   

Logical Switch 2: Is active when LO1 is active AND my throttle cut switch is in the throttle enabled position

   

Logical Switch 3: Is a sticky switch that is activated when LO2 goes active, and deactivated when the throttle cut switch goes to the throttle disabled position. 

This switch is used to control when the engine is active, and when to set CH5 to 100 

   

Logical Switch 4: Is active when LO3 is inactive, and the throttle cut switch is in the throttle enabled position. This occurs when the throttle enable switch is turned on, but the throttle is not at the minimum position

   

Then I have a number of spection functions that take input from those logical switches.

   

When LO3 is inactive, the throttle is overridden to -100, and the radio announces 'throttle cut' (or 'engine off' in some of my planes)

When LO3 is active the radio announces 'throttle active'

   

When LO4 is active, the radio announces 'throttle warning'

   

When LO3 is active, the radio overrides CH5 to 100 (enabling all the ELRS goodness)

[greggold]

I have a few logical switches which provide me with a safe starting mechanism for my planes:



Logical Switch 1: Is active when the throttle stick is less than -98 (i.e. it's at the minimum position)



Logical Switch 2: Is active when LO1 is active AND my throttle cut switch is in the throttle enabled position



Logical Switch 3: Is a sticky switch that is activated when LO2 goes active, and deactivated when the throttle cut switch goes to the throttle disabled position. 

This switch is used to control when the engine is active, and when to set CH5 to 100 



Logical Switch 4: Is active when LO3 is inactive, and the throttle cut switch is in the throttle enabled position. This occurs when the throttle enable switch is turned on, but the throttle is not at the minimum position



Then I have a number of spection functions that take input from those logical switches.



When LO3 is inactive, the throttle is overridden to -100, and the radio announces 'throttle cut' (or 'engine off' in some of my planes)

When LO3 is active the radio announces 'throttle active'



When LO4 is active, the radio announces 'throttle warning'



When LO3 is active, the radio overrides CH5 to 100 (enabling all the ELRS goodness)

Liam

I suggest your method is too complex. Many members may be flying with ch 5 not armed (see PRCAC whatapp thread), which means the dynamic power is not as fast as it should be, although it still works. A simple on/off switch method is required for these members.  Ch 5 remains empty in the mixer, but you assign a switch to arm or disarm ch 5. If you use a throttle cut/thr-active switch (which is always active when the plane is in the air), this switch is set in a special function to override ch5, so that whenever the thr is active, the plane is armed. 

Greg

[caffeine]

Liam

I suggest your method is too complex. Many members may be flying with ch 5 not armed (see PRCAC thread), which means the dynamic power is not as fast as it should be, although it still works. A simple on/off switch method is required for these members.  Ch 5 remains empty in the mixer, but you assign a switch to arm or disarm ch 5. If you use a throttle cut/thr-active switch (which is always active when the plane is in the air), this switch is set in a special function to override ch5, so that whenever the thr is active, the plane is armed. 

Greg

Yes, it seems complex, however the alternative allows for the folowing scenario:

Throttle cut switch active (throttle disabled), throttle stick not at idle.

Switch throttle cut to inactive (i.e. throttle active) and the motor starts moving straight away.

With my setup, the radio will warn in this scenario that the throttle stick isn't at the bottom position, and the prop won't move.

[secant0give]

Thanks for posting this
Very informative
I’m just setting a few things up with ELRS at the moment.
    I’m using Ardupilot and 5 is usually the flight mode channel but it’s easy enough to map to another.
    Normally use throttle -100 and full left for 2 seconds to disarm and full right to arm.
I can easily set up channel 5 to follow that with some logical functions