We have an old can machine which uses a NRI G13.6000 (flat cable ribbon serial) as a coin acceptor. Now I need to trick the machines relays board to think that a payment has been made.
The NRI has several output channels, but the one I need (channel 8) sends out a pulse to the board. I need to emulate that Pulse with the push of a button.
This is the description of the output channel of the NRI:
You have varied the duty cycle, but the frequency remains the same, namely 490 Hz.
I don't see the significance of this 111Hz from what you've said so far.
Edit.
In case you don't understand the difference, consider a signal with one millisecond high, and nine milliseconds low. The frequency is 100Hz, and the duty cycle is 10%.
A signal with nine milliseconds high and one millisecond low has the same frequency, but a 90% duty cycle.
No, PWM is not the answer.
The PWM frequency is fixed unless you want to fiddle with registers.
Using micros () may be much simpler.
Have a look at blink without delay.
Unfortunately I don't have access to a scope but I have solved this issue outside the arduino so that I only have to use a relay to achieve what I want to do. Not a real neat way to do it, but it will suffice.
Thanks for all the advice and information given. Maybe in the future when I am more able with arduino's sdk I'll take another attempt at cracking the puzzle.