Now that I have had hands on experience with oled-exp, this is what worked for me, including preserving whitespace and newlines:

oled-exp -c write "$(ls -FCs1|sed 's/$/\\n/g')"

Now that I have had hands on experience with oled-exp, this is what worked for me, including preserving whitespace and newlines:

oled-exp -c write "$(ls -FCs1|sed 's/$/\\n/g')"

There are two main ways in bash to pipe to oled-exp.
The best way is to use shell substitution like this:

oled-exp `ls -l`

Another way, that will probably munge up your whitespace, would be:

ls | xargs oled-exp

I believe that it only supports 7-bit ASCII. Those and ñ chars are not in 7-bit ASCII.