This question already has an answer here:
- How to get more than one uart interface 10 answers
is a quite interesting question that I was not able to fully answer for my rPi Model B+ v.2 - the one with the extended 40pin connectors.
To avoid this beeing a useless clone of the original question, I am going to be more specific:
- Raspberry Pi Model B+ with 40pin connectors only
- goal is to have something like ttyAMA1 or ttyS0 AND ttyAMA0 -> two seperate com-Ports
- NO USB-Adapters
- NO IC-Based Shields
- some resistors or caps if needed would be ok
- a sound explaination on why a second com-port on the B+ is not possible is ok as well!
Why do I think this should be possible?
According to the Documentation of the BCM2835 (Page 10 & 175) and these Pages:
there is a mini UART and the PL011 UART and I eighter miss something or just not understood why this second UART is unavailable by default.
My rPi is otherwise configured good so far and the ttyAMA0 works fine.
So, has anybody an idea how to activate ttyAMA1 or the reason why this is not possible?