I want to use two LEDs to show send and receive on my max232 RS232 to TTL (5v) converter. I have seen this method as the most conventional way to power an LED for max232:
I tested it and the LED light was very dim and decreasing the resistor value resulted in voltage drop at TTL level.
What is a more intelligent way to do this? Can I use two N-channel MOSFET and connect the gates to RX and TX and use a separate 5v between the Source and Drain? What are the pros and cons of this approach?
I have too many IRF3205 and I can use them. I think they will serve the purpose unless you think the specs are not good.
If it is good what resistor value seems reasonable between Rx/Tx and the gate of the MOSFET?
And one last question. Do you think a pulse stretcher is going to be necessary with this approach? or at least recommended? I am not familiar with them. If it is necessary or recommended I'd be thankful if you could show me a simple way to implement it. I am a tyro at best in electronics so I need a very simple solution... (like LM780x for voltage regulation / max232 for level conversion without too many details and components)
Thank you very much in advance.