Greetings!
I have created a simple circuit which uses an ADC pin to detect changes in the signal of a speaker terminal in order to know whether there is sound playing or not.
It works fine until I connect my servo motors. when they are active i get false readings making me think that there must be voltage spikes due to the high power demands of the servos.
I know that servos can be stabilised by using a capacitor.
I am using 3 servos. Since they are all connected to the same positive/ negative terminals i would presume that i need to attach a capacitor across which is able to store enough power to provide for all 3 servos? There are also quite a few other components drawing from these terminals, should i need to worry about how they will affect the operation of my capacitor in stabilising my servos?
Many thanks!
How are you powering the servos? They should NOT be powered from the Arduino.
If they are powered separately and you still have a problem then post your program and a clear diagram of all the connections
...R
Currently its powered via USB so everything's drawing from the 5v line(on the arduino). They are only small sg90 servos which dont a great deal of current.
Would this still cause a problem? The thing is that my idea requires using the USB power supply so sourcing another supply would be problematic....
gonadgranny:
Would this still cause a problem?
Simple way to find out is to try. Temporarily power the servos from a pack of 3xAA cells.
You have not posted either your code or your connection diagram!
...R
Yes i'll try hooking up to az battery as you suggest. the reason for not posting my circuit diagram is because its simple within the scope of what is relevant. ie. 3 servos all connected to ground and 5v on and arduino nano and each with their own signal line going to a digital pin.
I have a RC setup which 'smoothes' my AC signal from the audio which is picked up by the ADC pin.
The code takes a sample every millisecond to determine whether there is sound playing or not. I explained rather than shown because i cant draw circuit diagrams(currently) and the code is quite expansive. if you need more information do let me know. Thakns again.
gonadgranny:
the reason for not posting my circuit diagram is because its simple within the scope of what is relevant. ie. 3 servos all connected to ground and 5v on and arduino nano and each with their own signal line going to a digital pin.
That is not a sufficient reason. Verbal descriptions of wiring connections are easily mis-interpreted. And I frequently get simple wiring wrong. Drawing a circuit diagram is a great way for me to spot mistakes.
The other thing is that it is very easy to waste time wondering if the root of a problem is elsewhere when part of the information is not available - even if it eventually proves to be irrelevant.
...R
how would you recommend drawing the diagram? is software usually the route people take? thanks.
Fritzing is a free diagram software Download Fritzing
thanks
Stuart
Express Sketch is what I use. It is simple, easy to learn and free. It is not as powerful as Eagle or KiCad but much easier for simple schematics. Also it is easy to make your own components, should what you need not be included.
I go with @vinceherman in the first instance.
I guess it may be possible to produce an understandable diagram with Fritzing but I have never seen it done. All most people seem to use it for is to produce meaningless pretty pictures. And the pin names are never readable.
If you are familiar with regular drawing (art) programs on a PC they can be a perfectly good alternative to pencil and paper. But if you are not familiar with them they have a steep learning curve. I produced the diagrams in this Simple nRF24L01+ Tutorial using Libre Office Draw.
...R
hi is it not possible to upload an image from my computer?
acestu:
Fritzing is a free diagram software http://fritzing.org/download/thanks
Stuart
NNOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!! !! !! !! !!
groundFungus:
Express Sketch is what I use. It is simple, easy to learn and free. It is not as powerful as Eagle or KiCad but much easier for simple schematics. Also it is easy to make your own components, should what you need not be included.
YEEESSSSSSSSSS!! !! !!
Fritzy does not encourage component like labels and pin numbers/names detail needed to make a decent schematic.
Tom.....
TomGeorge:
NNOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!! !! !! !! !!YEEESSSSSSSSSS!! !! !!Fritzy does not encourage component like labels and pin numbers/names detail needed to make a decent schematic.
Tom.....
Hi dude
I just started with friznei..friz...frizz..that program. But I found it a little slow - what is express SCH/PCB like with going back & forward between PCB and schematic views?
In frizz..frittzzz..ffff....ff.. the other program, it goes back & forwards seemlessly and I like that. But I like the look of this other program. Whats your thoughts? cheers
i never said it would be pretty.
That LED doesn't have a current limiting resistor? Might want to add one.
Everything is dangerous in that circuit.
Three servos on the 5volt rail, LED without CL resistor, and a speaker signal that can damage the A/D input.
For the speaker input:
Use a 1N4148 diode with 10k resistor in series between speaker and analogue-in (and share grounds).
Change the 3k resistor to 100k, and the cap to 100n.
Leo..
Also, why is there no separate power supply for the servos? No excuse not to.