Electronic – Detect Hama IR Remote Protocol

Normally the actual sensor consists just of one or two photodiodes (two if it is a differential sensor) sensitive for thermal IR radiation and most of the time a FET transistor integrated in one casing.

So there is not much "protocol".

Take a look at this example datasheet

Of course you can buy also more complex sensor circuits that implement whatever protocol.

A simple way to debug would be to use an oscilloscpe to compare the difference between the real remote and your Arduino signal.

Either use an IR receiver and scope the results of both Arduino and remote with the same data sent. Or open the remote and scope the lines directly and compare with the Arduino data driving lines. Then adjust your code to make the two identical. As @mpflaga says, the timing between sends is a likely suspect.