What’s Logical Change in EdgeTX Radios and What You Can Use It For

Logical switches are one of the vital highly effective options in FPV drone radios that run EdgeTX. It may be intimidating and complicated for newcomers. On this tutorial, I’ll clarify what logical switches are in easy phrases, how they work, and what you’ll be able to truly use them for in FPV. In case you are flying quads and simply getting began with EdgeTX, that is a kind of options you most likely gained’t contact immediately. However when you perceive it, you’ll understand how highly effective it’s.

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What’s Logical Change

A logical change is a digital change inside your radio.

It’s NOT an actual bodily change you’ll be able to flip along with your fingers. As an alternative, the radio turns it ON or OFF robotically primarily based on guidelines (situations) you program.

Bodily switches are sensible, but additionally fairly “dumb” as a result of they’ll solely be managed by the person. Logical switches allow you to create sensible conduct in your radio. They’re nice when a standard change will not be sufficient.

For examples:

• “I would like the radio to warn me when RSSI will get too low”
• “I would like the radio to learn out voltage when battery will get low”
• “I would like the radio to reset timer 10 seconds after I disarm the quad”

So as a substitute of bodily flipping a change, the radio is doing the switching for you primarily based on logic, that’s why it’s known as a logical change.

And the likelihood is limitless, that’s what makes logical switches so helpful.

Find out how to Differentiate Bodily Switches and Logical Switches

• Bodily switches are labeled with letters resembling SA, SB, SC, SD, SE, SF, SG, SH, and so on.
• Logical switches are labeled L01, L02, L03, L04… (as much as L64 on most EdgeTX radios).

The place to Discover Logical Switches in EdgeTX

To seek out and create logical switches:

• Press the MDL button
• Press PAGE a couple of occasions till you discover Logical Switches

Primary Construction of a Logical Change

Every logical change has a couple of settings, however an important ones are:

• Perform
• V1
• V2
• non-obligatory AND change
• Length
• Delay

The essential concept is straightforward:

• Perform = what check the radio ought to carry out
• V1 = first worth, the factor being monitored
• V2 = second worth, the edge or comparability worth

For instance:

• Perform = a
• V1 = battery voltage
• V2 = 14.4V

Which means:

Flip this logical change on when battery voltage is lower than 14.4V

As soon as that occurs, the logical change turns ON (lively).

Delay

This implies the situation has to remain true for a minimum of this period of time earlier than the logical change prompts. That’s helpful for avoiding false alarms. For instance, if RSSI (or battery voltage) dips for a break up second, I could not need an alert instantly. I can add a delay so the warning solely triggers if the issue lasts lengthy sufficient.

Length

This controls how lengthy the logical change stays lively. If I go away period at zero, it stays on solely whereas the situation is true. These options develop into extra helpful as your EdgeTX setup will get extra superior, for easy setup you’ll be able to go away it unchanged.

Widespread Logical Change Features

• a = x → “1st worth equals to 2nd worth”
• a > x → “1st worth is larger than 2nd worth”
• a < x → “1st worth is lower than 2nd worth”
• AND → Each situations have to be true
• OR → A minimum of one situation have to be true
• Edge → Detects when one thing simply modified (helpful for momentary actions)
• Sticky → Makes a change “latch” (keep on till one other situation turns it off)

There are numerous extra capabilities out there, verify EdgeTX guide to be taught extra.

Word you could additionally use logical switches and bodily switches inside one other logical change (e.g. you’ll be able to assign L1, L2, SA, SB and so on to the V1 and V2 fields of one other logical change). It means that you can mix a number of situations and create extra superior or difficult behaviors. It’s highly effective however can get complicated quick and turns into very laborious to debug later. Typically you need to hold your logic as flat and easy as potential initially.

Instance: Low Battery Warning

This is likely one of the best and most helpful examples.

You can also make a logical change that claims: Activate when battery voltage is beneath 3.5V per cell.

1. Navigate to Logical Switches in your radio
2. Scroll to an empty line (for instance, L01) and press ENTER
3. Configure the logical change as follows:
   1. Perform: a
   2. V1: RxBt
   3. V2: 3.5V (you’ll be able to change it to any voltage you need)
   4. Delay: 3 seconds (this delay reduces false positives attributable to voltage sag throughout punchouts)

Within the Betaflight CLI, enter:

set report_cell_voltage = on
save

Now L01 turns ON every time your quad battery drops beneath 3.5V per cell.

Then in Particular Features, you should use L01 to play the worth “RxBt” (with an interval of 10s so it doesn’t get too annoying). I even have one other particular operate on the highest that performs the voltage after I press the SH change.

I’ve a complete tutorial that goes into element learn how to arrange low voltage alarm right here: https://oscarliang.com/edgetx-voltage-callout/

What Can You Use Logical Switches For?

Aside from Low battery warning, newbie pleasant makes use of of logical switches are:

• Low RSSI or low LQ warning: Use telemetry to warn you when your hyperlink high quality drops.
• Automated channel activation: Activate a channel, LED, or function when a situation is met.
• Safer Arming: if throttle will not be absolutely low, radio alerts you it’s not protected when making an attempt to arm
• Multi-purpose Knob: knob is already utilized in particular operate, however you’ll be able to create a logical change that checks knob place, then use that logical change because the set off for one more particular operate

Every other inventive use of logical switches? Tell us within the feedback.

Ultimate Ideas

Logical switches sound extra difficult than they are surely. All they do is let me inform the radio:

“When this situation turns into true, deal with it like a change has been turned on.”

That situation may be any radio controls, telemetry information, or a mix of issues

As soon as I’ve that logical change, I can use it wherever in EdgeTX similar to a standard change. You possibly can even use logical switches and bodily switches inside one other logical change to create actually advanced conduct.

And when you get snug with them, you’ll begin discovering every kind of intelligent methods to make use of them.