I'd like to build an interface composed of USB to TTL, micro USB to TTL and RS232 to TTL and want to speak to one TTL master device. I've got myself the necessary modules.
Only one interface is supposed to be connected/plugged in at a time. So it's basically a providing-the-option thing.
I realized that pluging them all together doesn't work out for some reason. All modules work when being used separately though.
When the Serial system is idle the normal process is for the TX pin to hold the line HIGH. But the diodes prevent that so the resistor is used to hold the line HIGH at the RX end.
Of course with a system like this there will just be garbage if two or more of the slaves talks at the same time so your master program must control which slave is allowed to talk. If the master cannot do that then this system won't work.
The more I think about your answer the more I believe I've mistaken my problem and the concept of the other thread.
Doesn't all my optional interfaces pose as "Masters" here?
Here is an example leaving "Master" and "Slave" out of it:
I plug in my Computer (Win10 and/or Ubuntu) into Interface 1 (e.g. RS232). Interface 2 and Interface 3 stay empty. (They are powered though)
The device I connect to pops up as a COM (serial point) device in my OS. I assume that device is nothing but the RS232 to TTL module.
I can now send commands to connect, transfer and receive data from the desired TTL device.
Do you think it is going to work based on your diagram anyway?
PS: I'm really curious whether I'm just too bad finding what I'm looking for. Having different interfaces as an option to connect to a device seems like a pretty common task to me.
