Coin acceptor pulse error

Hi everyone, i have something to ask about coin acceptor.
If i touch the plug of the power adaptor connected to coin acceptor it gives pulses even without inserting coins.
My wiring is :
White coin pin to interrupt pin with 10k ohm resistor
Black is connected to adruino GND and adaptor Gnd
Red is connected to +12v power adaptor

Simple solution, do not touch the plug.

When you touch the plug, your body is sending electrical signals which are especially sensitive to A/C electrical interference (building wiring or hum). Hence the need for ESD (static discharge) protection and also the buzz when you touch an amplified input jack on a stereo. If you have access to a scope you can see it first hand.

I'm sure you could filter some of it out with resistors, but the easiest filter if protecting you from touching the plug.

It has already 10k ohm resistor connected from white wire or coin pin.
Is there no other solution for it except for not touching?...

Hooking a resistor from the signal to ground to hold the signal low will limit low current interference. Finding an ohm value that won't interfere with the current from the output but limit the interference will require some tinkering. (IE on my scope I think I used a 2k).

It sounds to me like the signal ground is not properly connected or there is a pull-up or pull-down resistor missing. Can you point to the owner's manual for your particular coin acceptor? Or a model number? Or something to identify what you have?

twist a GND connected cable to your other cables - that will help shield things a bit too - but you are likely missing a pull-down/up somewhere

Its a universal coin acceptor that has maximum of 5 coins to be programmed... i have a pull up resistor of 10k ohm in coin pin (white wire) connected to arduino interrupt pin... but still if plug is touch.. it gives pulse even coin is not inserted.

Max2p:
i have a pull up resistor of 10k ohm in coin pin (white wire) connected to arduino interrupt pin..

That does not describe a pull up resistor would be implemented.

Now had you said you have the output pin going going to arduino pin along with 10k ohm resistor going to the 5v pin I would believe you likely wired it correctly but a drawing/photo would prove it.

If you want serious help, post real pictures, code, and data sheets.

Max2p:
i have a pull up resistor of 10k ohm in coin pin (white wire) connected to arduino interrupt pin...

By description does not sound like a true pull-up. I would think a pull down is necessary as I assume the white white is normally LOW and switched HIGH? No idea without you giving more information.

COIN
ACCPT --------------o---------------ADRUINO
|
|
GND

If you look at this video at 1:56 you’ll see the wiring of a 10k Ohm PULLUP resistor to the sig pin (if you have a similar device)

Hi,

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks.. Tom... :slight_smile:

This is exactly how i wired my coin acceptor to arduino

Hi,
OPs ciruit;
d4a076519216c6ad7f2fdd085fc88afdbf6a374a.jpg
Tom… :slight_smile:

I think i cant create any circuit, i am not familiar in electronics... i just follow wirings in that fritzing image.. coin acceptor device is the same

I can see this is exactly extracted from that video - question is did you wire it really like this… a picture always help to see reality (you might be right though)

J-M-L:
I can see this is exactly extracted from that video - question is did you wire it really like this... a picture always help to see reality (you might be right though)

I wired it exactly like on that picture

According to data sheet and how you wired it, it should be correct physically.
In that video you posted, he seemed very deliberate to not touch anything else but put coin in the slot.

Datasheet for unit in the video http://www.jimark.cz/upload/files/produkty_soubory/ict-uca-1-uca2/UCA_Series_Installation_Guide(EN).pdf

I would disconnect just the signal wire from the coin machine and test to see if the arduino triggers by touching the wire or frame still. Go from there.

Possible the counter itself has a defective internal ground connection which is resulting in a capactive sensitivity

Slumpert:
I would disconnect just the signal wire from the coin machine and test to see if the arduino triggers by touching the wire or frame still. Go from there.

Possible the counter itself has a defective internal ground connection which is resulting in a capactive sensitivity

I have tried disconnecting signal wire to arduino and touching the plug... it really gives a pulse count

I think i have to change my code and try not using interrupt pin

If you get unwanted pulse, this is what you need to fix... interrupt or not, the arduino will see a signal and can’t tell if it’s legit or not...