Nayax and coin mech problem

[DanielP]

Hi all,

I am writing to see if I can get some help with this project I am doing at the moment. I have a coin payment scale that I need to update by adding a Nayax credit card payment system to it. After a few days of work, the Director from Nayax and I managed to successfully connect it, take payment and release the scale timer. The problem I have is that there is some sort of conflict somewhere because the credit card system won't work if the coin mech is connected as well at the same time. The coin mech and credit card payment work on a pulse system which is sent to the scale motherboard telling it to release the timer. Three wires go from the coin mech to the motherboard: 12v power, pulse and ground. I connected the same wires from the Nayax credit card system which works only if the coin mech is not connected. When both are connected, Nayax system will take payment but does not send pulse to the scale to open the timer. I have tried a diode on the pulse cable from coin mech but same result.
I don't have an electronics background and I am learning on the way so please be kind.
Thanks

Daniel

 

[Harald Kapp]

Normally you cannot connect two ouputs (from the coin mechanism and from the card mechanism) to a single input.
You want to activate the system bei either of the mechanisms, so you need to implement a logical "OR" function, i.e. the output is active if one of the two inputs is active. There are several ways such a function can be implemented. We need to know a bit more about your setup:

• What is the idle level of the two outputs (i.e. voltage to ground when no payment has been made)?
• How long is the pulse (approximately)? Is there just a single pulse ore a pulse train?

Using diodes to decouple the two signals may be a step in the right direction, but you'll need at least a resistor to ensure a stable idle level on the input of the scale. Here's an example that should work for positive pulse (idle = 0V) from the mechanisms:

R1 ensures 0V at the scale's input when no pulse is active on either output of the mechanisms. The value of R1 needs to be low enough to ensure a defined low level when no pulse is active. On the other hand R1 needs to be high enough that the outputs of the mechanisms stil can generate a defined high pulse when active. YOu may need to experiment to find the correct value. If this doesn'z work, you may even have to add an amplifying stage (transistors) to restore the pulse signal.