An electronic set of " trainer wheels " for your drone.


 I'm still pretty new to all this, so firstly, let me say thank you to all those that have helped me get my head around quads and setting up my X 525.

I have a quite frustrating problem..

I want to program what is effectively, " trainer wheels " for my drone in the form of an auto minimum altitude hold using  an Arduino board, and an Ultrasonic detector as a "sensor" that will work along with my KK board.


With the Ultrasonic facing downwards, and a sketch including at a pre-determined height ( above 4 feet for example ) there will be no ground detection.

The usual state will be a "low" and the Arduino would do nothing but loop through the sketch looking for this Ultrasonic trigger.

However, - when the ultrasonic DOES trigger, the Arduino should sense a "high state". - When this happens it should  ( fuzzy logic here  ok? ) be able to detect the CURRENT throttle setting via the radio receiver and prevent any throttle range below it. - ( and yes, this feature would be on a switch on the RC transmitter lol! ).

Obviously, if the Ultrasonic detection is not made, ( switched off ) then its full range as usual.

Where the Servo comes in, is that it will be my throttle servo currently linked to the KK board via the receiver.

Like I said, I'm new to Arduino programming, and I'm still getting my head around things like GOTO statements are not generally I'm having a hard time figuring out the finer points of conditional statements, if then, gosub, ( etc )

If you have any ideas, please let me know.

I've only been learning Arduino programming foe a day so far but this is a little harder than making an LED blink.

P.S. - for the record, I DID manage to learn enough to make that LED blink S.O.S. in Morse. Code in a loop.

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  • Hi, I'm working on something close to this.

    Here my progresses


  • Your sonar is going to give you a range measurement.  It's not going to toggle a pin as you need the uC to send the pings and also to read the response.  Most ultrasonic sonar is going to give you a reading from a few cm to about 4 meters (13 feet), so a lot of the time you'll be in sonar range.

    I'd check out the diydrones store, someone has probably already written a lot of the code.


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Dec 3, 2020