Hi
I am planning for a project where I need to use:
As per the coin acceptor's datasheet it uses Working voltage DC +12V ±10% and Working current 65mA ±5%. But I have a feeling it may draw more current.
I will be putting a very low load on the servos.
Can anyone help me confirm whether 12V DC, 2 Amp power adapter will be sufficient to power all the items including the Arduino.
Thanks in advance.
Servos need a 4.5 to 6V supply. The Arduino's regulator can only handle 1 Amp and the servos can draw as much as 1A EACH so you can't run them off the Arduino's 5V line. You will need a buck regulator to drop the 12V to about 5V. If the servos have almost no load you can probably survive on 12V 2A. If the Arduino resets when you move the servos you will need to upgrade the power supply.
Thank you for the prompt response.
I think I can manage with 1 servo though.
What I also found out is the coin acceptor uses a working current of 65mA.
I had another query. I connect the wall adapter to the Arduino (DC jack) as well as the coin acceptor via the breadboard. I also connect the Arduino to the USB of my PC to for programming and monitoring the serial output, is there any harm in it?
I mean will there be any backpower through the USB and damage the Arduino board or my PC ?
nileshrg:
I had another query. I connect the wall adapter to the Arduino (DC jack) as well as the coin acceptor via the breadboard. I also connect the Arduino to the USB of my PC to for programming and monitoring the serial output, is there any harm in it?I mean will there be any backpower through the USB and damage the Arduino board or my PC ?
There is a MOSFET and comparator that disconnect USB power if the Vin voltage (from the Vin pin or DC jack) goes above 6.6V. That protects the USB connection against backpower.
Thanks for your quick response.
For the time being I am trying to connect a simple circuit with a basic code to check the pulses from the coin acceptor but having issues.
So my connection is as follows:
Coin Acceptor 5V (red wire) --> 12 V Power (wall outlet)
Coin Acceptor GND (black wire), Arduino GND (next to digital Pin 13) and 12V GND all three connected together.
Coin Acceptor Coin (white wire) --> Arduino Digital Pin 2 (Interrupt 0)
The issue I have is there is no pulse output from the Coin wire.
I have also tried connecting a pull up resistor (10 Kohm) between the coin wire and 5V of the Arduino, still no output.
I have programmed and reprogrammed the coin acceptor multiple times, I have changed cables as well.
My code is as follows:
const int coinInt = 0;
int coinsChange = 0;
void setup()
{
Serial.begin(9600);
attachInterrupt(coinInt, coinInserted, RISING);
}
void coinInserted()
{
coinsChange = 1;
}
void loop()
{
if(coinsChange == 1)//Check if a coin has been Inserted
{
coinsChange = 0;
Serial.println("coin inserted")
}
}
One question I have is whether the common should be on Ground of the Arduino should be the GND next to digital Pin 13 or the GND next to the 5Vin ?
So my connection is as follows:
Coin Acceptor 5V (red wire) --> 12 V Power (wall outlet)
Does the coin acceptor has an random-voltage acceptor circuit too?
Not that I am aware of.
I am using 12 V DC, 2 Amp power supply.
nileshrg:
Coin Acceptor 5V (red wire) --> 12 V Power (wall outlet)
Are you saying that the coin acceptor requires a 5V supply and you are connecting it to a 12V supply?!? That seems dangerous.[/quote]
nileshrg:
One question I have is whether the common should be on Ground of the Arduino should be the GND next to digital Pin 13 or the GND next to the 5Vin?
It does not matter. They are both connected together on the Arduino board. Also connected to the outer shell of the DC jack and the Ground pin of the ICSP header. Since Ground is needed so often they put in several ways to connect to it.
My bad. Typo.
Coin Acceptor requires 12V and not 5V. Thanks for pointing that out.
So I have no problem setting up the coin acceptor and sampling it. But one thing I did realize is after setting up the coin acceptor, when I drop the coin through the slot, it show 00 on its 7-segment LCD display. I feel it should show the number of pulses it has been programmed for.
For example if I drop a quarter it should show 04 on the display but it shows 00.
May be this could be the issue and hence no signal pulses are recognized ?!?
nileshrg:
For example if I drop a quarter it should show 04 on the display but it shows 00.
The documents I saw for the Sintron CH-926 Coin Acceptor say that the timer display comes on to the programmed time when the amount of money reaches the amount for the minimum time. What is your timer programmed for?
The coin acceptor I have JY-926 (CH-926) does not have a separate timer board as such.
Yesterday I reprogrammed it multiple times for 1 coin, 2 coins and 3 coins. It accepts and rejects coins the way it should. So I know the machine is working fine.
After programming though, when I restart and insert coins, it shown 00 on the display for a split second till the coin drops.
It has NO-NC selector which I keep on NC and it has fast (20ms), medium (50ms) and slow (100ms) selector which I keep on fast.
I wonder what could be the issue.
nileshrg:
I wonder what could be the issue.
Do you have a reason to think that the display should be doing something different? Did the documentation that came with it say what the display should do when you are not programming the device?
I solved it !! 
Firstly to answer your question - yes that is exactly what it should do. It should show you the number of pulses you have programmed for each coin when the coin is inserted. And I found this out in one of the videos on youtube when the user was inserting the coins it showed a number like 02 or 04 and not 00.
After scouring through the internet with no luck I had almost given up when I took a shot at what is the AP mode in the coin acceptor as per the manual. I dont know what AP stands for but it actually lets you control the output pulse ratios. So basically it lets your program how many pulses it should output for every coin drop. As per the manual it is default at 1 and so I never paid attention to it. But what I realized is every time I reset the coin selector, the AP mode was reset to 0 and not 1 and hence the output pulses were always 00 !! Also not all manuals mention the AP mode.
This is how we get into the AP mode - hold the SET and ADD buttons simultaneously for a few seconds. Then leave the ADD button but keep holding the SET button till AP shows up on the display. Press the ADD button to select the value of AP mode (which is also the value of output pulses). The coin selector will generate 1 external signal output when the internal signal "P" value of the parameter reaches the value. To make it simple keep it at 1.
I hope the above explanation will help others who are stuck like I was. I was almost about to send the unit back as a broken piece.
Thanks for your help.
My next aim is to store the total balance inside the Arduino when powered off and restore it after power on. Any ideas how can I achieve that ?
Hi
As I want to make this a standalone system, I will have to use a common power supply.
Attached is my circuit. I feel this should be fine but wanted to double check whether 12 V DC, 2 A direct to Arduino shouldn't damage the board.
If there is a better way to power all the parts, please let me know.
Thanks.
nileshrg:
Attached is my circuit. I feel this should be fine but wanted to double check whether 12 V DC, 2 A direct to Arduino shouldn't damage the board.
You can run the Arduino on 12V. It would be slightly better to use the DC jack instead of the Vin pin. It has a reverse-voltage-protection diode which not only protects the Arduino if you get the voltage reversed but it also drops the voltage a little bit making it slightly closer to the ideal 7V instead of the recommended maximum of 12V. A more efficient solution would be a 5V buck converter connected to the +5V line.
DO NOT connect your servos directly to 12V. Typically they are designed for 4.5-6V. They can also draw as much as 1 Amp each. If you use a 5V buck converter for the Arduino and it can handle 24 Watts you can use it to also power the servos.
DO NOT connect your LCD display directly to 12V. Typically they are designed for 5V. You can connect it to the Arduino 5V pin since it draws little power.
I would use the DC jack but since I have to share the GND with the coin acceptor I split the 12V DC using a converter. I have attached the pic.
How do I power the Arduino and coin acceptor from a single power supply of 12V DC ?
