bugfix: same data conversion in transmit as in read method

[botmonster]

It took me some time to debug this. Transfer method worked pretty random when list of integers were converted literally to such string: "[1, 2, 3]" not to binary string :)

[tomstokes]

Hey botmonster, thanks for the pull request, and I'm sorry the interface threw you off at first.

I originally designed this whole package as a cleaner drop-in replacement for another system that used the same read/write interface included here and unfortunately the quirks carried over as well.

But you're right in that this should be cleaned up to make more sense in the general case. Let me spend some time on getting this sorted out and making the documentation match as well. Thanks for the input