Send raw byte array over BLE

I'm using a MDBT42.

I have an iphone app which connects over BLE and can receive data from the MDBT42 over UART.
On the MDBT42 I use the print statement to send a load of byte in ASCII format, i.e. I send literal 'FF' for 255. In the iphone app I have to decode the ASCII characters received to generate a byte array which is then decoded again into a set of glucose readings.

This all works fine, but there must be a better way to send just a big byte array without having to decode ASCII characeters in the iphone app.

Any ideas? I'm sure I've missed something obvious here.

Thanks,
Marco