Still working on FullDuplexSerial2.spin2. The original FullDuplexSerial.spin supports a MODE parameter.
bit 0 - invert rx
bit 1 - invert tx
bit 3 - open-drain/source tx
bit 4 - ignore tx echo on rx
The last two are giving me grieve.
I can configure inverted input/output for rx and tx, but I can not figure out how to config tx to be open-drain/source.
Another thing I am stuck with is how to suppress tx echo on rx with a buffered driver.
The current version of FullDuplexSerial in Fastspin tries something alike
if rxtxmode & %1000
But that can just work with a not buffered driver, so how to solve that?