I need Help with ATMega16..... urgent

[Eng_SAME7]

Hello guys hope you are fine,

I'm working in a project using ATMega16, and I have a timer / Coin acceptor. this timer will take a number of pulses from the ATMega16.

but the thing is that the ATMega can output from 10 mA - 20 mA I think... but my concern from the timer may take more than that...

so I need a simple schematic for a protection circuit using OPTO-Isolator or transistor to protect ATMega16..

 

[alexan_e]

I'm not sure what the requirements are, how much current do you need?
Do you need the opto isolation or not?

A low side switch looks like


with the load in place of the relay.

Alex

 

[Eng_SAME7]

The requirements are that:
- Timer "load" may take more current from the ATMEGA16, and this can damage the ATMEGA.
- Yes I need an opto-isolator for protection.... so I need the connections "schematic diagram"...

hope u can help me