Nayax and coin mech problem

[idanielp]

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

 

[dr pepper]

I dont think we have enough info.
Are you absolutely sure the pulse connection is just a straight forward on/off pulse, from what you said this sounds like it might be a data line, that would explain why one or the other works.

 

[Les Jones]

Hi Daniel,
If you just connect two wires that each send pulses in parallel then the one that is not sending pulses is going to hold the signal high or low depending on the static state of the signals. You need to do a logical "OR" of the signals. If the active state is high you would use an "OR" gate. If the active state is low then you would use an "AND" gate. You would also need to do something to ensure that both signals cannot occur at the same time. As this is a payment system I would expect the communication to be more secure than just pulses. As "dr pepper" has said I also suspect this will be a data steam probably with a checksum. There could even be bi direction data on the data line for handshaking.

Les.

 

[Tony Stewart]

Depending on logic of pulse,

If positive logic, it is active high so for shared use a passive pull down R and diode OR logic ( with common cathode) can share the pulse input line.
If negative logic It is the reverse with common anode diodes.

Details on logic voltage and polarity are essential.

 

[KeepItSimpleStupid]

Your not giving us enough information, but my suggestion is two diodes connected at the motherboard input. I'd try the band ends, one to each device first.