How to Turn a Servo into an LED Switch

[@tbg_linear9487]

Amazing video, making an landing light for my avanti rn

[@InvertedAviatorsRC]

Thank you! You should join the discord and post some pictures when you’re finished!

[@dannybear3121]

Very interesting. Who knew there is so many possibilities with LEDs and servos

[@InvertedAviatorsRC]

Yeah turns out LEDs and servos are pretty cool to work with!

[@murraymadness4674]

very clever hack! Funny that I was just thinking how to do something like this, and this popped up in my recommendations. I have a system that has one wire output to send the race position of the rc car, and I decided to use a servo output signal as its easy to generate. You could also use two leds for each polarity, so the race leader gets a green led lite on, and the second place gets a blue led, and all the other cars have no led lit. I'd like them to flash too, but I can add a simpler circuit to flash than have to decode the servo signal, in fact you can buy leds that flash themselves, might just do that. btw, can eliminate the pot and put in a fixed resistor to the leds for the 1.5ms center position.

[@InvertedAviatorsRC]

Thanks! Yeah I think it could work really smoothly for a race leader tracker system! And I've thought about getting a strobing LED, but I thought it would be cool if the flashing could be accomplished without any special additional things. I'll keep you posted if I figure out how to do it!

[@Bubu567]

@@InvertedAviatorsRC Replace the potentiometer with a capacitor in series with a resistor and a bleed resistor? You could adjust the on/off times by adjusting those resistor values.

[@shanesdiy]

Good stuff. PWM switches are fairly cheap these days but anyone that's been in the hobby for very long will likely have stripped servos laying around (unless they tossed them) they can get some new life out of. Everyone likes installing LEDs on planes now so great hack! Regarding that LED flashing logic we were experimenting with, I still think there is a way to make it work in logic but a 555 timer IC LED flasher circuit fed by your servo mod would let you set any pulse frequency/rate you wanted easily.

[@TankR]

A 555 driven by a signal sounds perfect for a pseudo strobe effect since they tend to oscillate a few times when they fire on big birds. And since its an H-bridge circuit the pads can flip flop positive and negative, so assuming the dead zone means no output (otherwise it would jitter hunting for the perfect angle) one could set the potentiometer signal to dead center (5k as the pots are typically 10k from what ive seen in other electronics, BTW, this video is wrong, the controller board reads the incoming signal, compares that to the value read from the potentiometer, and using an H-bridge circuit turns the motor in the direction it needs to make the two values agree) for no signal, and then put a LED/circuit on one 'direction' (say, down, or less than middle) and another on the other direction (up, or above), with the middle for off. Then just have the signal values go hard high(255, or whatever that is in common servo speak, full 1.99ms high(there has to be a low period for clock syncing), and hard low(0, or 1ms high 1ms low) over and over to trigger two flasher circuits! Just remember the pad is switching between positive and negative, so probably use a NPN or some such to trigger the circuit.

[@InvertedAviatorsRC]

Interesting! I haven't heard of a 555 timer IC LED flasher circuit, so I'll have to give it some research! My goal was to be able to accomplish the flashing without any extra parts, so I'll keep you updated on any progress!

[@InvertedAviatorsRC]

Thank you I appreciate the correction! We're always open to learning something new!

[@TankR]

@@InvertedAviatorsRC I was writing a main comment reply and decided to brush up on servo signaling .... then remembered why it took a week to wrap my head around while trying to condense it down into a digestible form. Its actually really clever, servos are incredibly passive on the silicon, but still an elegant solution. Impressively so aaaaaand then I got distracted running chip numbers, and big clive.. LoL All in all I thought the use was pretty neat, especially if it saves on IO and unnecessary hardwear (lighter plane = faster plane ;) ) Ive thought about reusing some servo brains for larger motors before by tapping the motor lines into some larger fets or transistors, but never as a circuit control point. Thats a really interesting hack! And an honest one too. Using a thing for something it wasnt designed to do. With that words over use these days proper hacks are few and far between. Even though I hate using that word for things that arnt, this totally is a hack. Like, this should be submitted to hackaday....get some real hacks on the janky site again! For the 555 thing, just make it do a quick monostable on-off-on-off and use your servo trick to either power it or a transistor to pass it power from the power inputs, and BAM! 2 strobe effect circuits from 1 channel! As long as you can automate the swing one way and back....IDK how spiffy those fancy controllers get, though I have seen them do some crazy stuff. Could need a diode to keep it off on the reverse swing though.....IDK, experiment. Thats why these videos exist, we bodgers who look at broken stuff and think "well, surely it cant ALL be dead, what can I harvest..." XD

[@InvertedAviatorsRC]

I just kind of figured something out with edgetx and then a servo switch. I just added it to our discord, so feel free to check it out! You are able to do it with any led too! discord.gg/xN5264Vb8q

[@calvinstreeting1173]

so if you put 1 led +- and one -+ and set potentiometer to mid point you could have left and right led :) very intresting..

[@InvertedAviatorsRC]

Yep you got it! Super simple!

[@johnnymaynard299]

Awesome Stuff !

[@InvertedAviatorsRC]

Thank you very much!

[@schstephane]

Hello, if we removed the potentiometer the servo do on/off ? i juste want a on/off on my chanel 3

[@InvertedAviatorsRC]

Hi! The potentiometer is essential for the servo to detect its position and provide feedback to the control circuit. If you remove the potentiometer, the servo will lose its ability to determine its position and won’t function as intended. However, if you're looking for an on/off functionality, you could manually rotate the potentiometer to one extreme (instead of leaving it centered). This could make the servo behave more like a simple on/off motor. Let me know if you need more help.

[@TheGreenJuicy]

Thanks man for this real good video. How about HV LED on a board (they need 12V input) so I want to power them directly from 3S LiPo. Can it work by just taking the white signal wire to the receiver and +- directly, or does the microboard in the servo has some kind of stepdown?

[@InvertedAviatorsRC]

Thanks for the kind words, and great question! As far as my understanding goes, a standard 9g servo can operate in the 4.8-6V range, and it can change the output voltage based on the input signal value to change the brightness of the light. If you directly powered the board with 12V, I think the microboard would fry because it takes the input voltage and steps it down. I think the solution would be to get a servo that can handle 12V of input, because then you wouldn't be bottlenecked by what the board can handle. I *think* something like this would work (amzn.to/4dr4vwo), because this servo can handle 12V of input.

[@TheGreenJuicy]

@@InvertedAviatorsRC Thanks mate, for normal usecase a cool idea to use old servos as aimple remote light switches, but in my case a bit tricky. If I would have a damaged HV servo lay around I would try it, but highest is only 8.4V rated here. Anyway, I prepare one for next LED setup😀, enjoy your day

[@InvertedAviatorsRC]

@TheGreenJuicy yeah absolutely! Have a great day yourself!

[@jamesturncliff5960]

First one again

[@InvertedAviatorsRC]

Thank you for all the support! Is it still windy over there by you?

[@jamesturncliff5960]

@@InvertedAviatorsRC rainy and windy no flying till I grow my fingernails back they got ripped off in my dog got attacked I have to balance 4 of my airplanes

[@InvertedAviatorsRC]

Ah sorry to hear that, yeah hopefully things get cleared up and you can get back in the air!

[@jamesturncliff5960]

@@InvertedAviatorsRC just have to hurry up and wait for my fingernails to grow back. They got ripped off when my dog got attacked I was trying to get the other dog off of mine

[@bennio_1641]

Second one again

[@InvertedAviatorsRC]

Hah you almost had him beat!