I need to find a way to trigger this [Hall Effect Sensor](http://parts.digikey.com/1/parts/948235-ic-switch-hall-effect-2x2mlpd-a3212eellt-t.html) with a non-permanent magnet. Does anyone know if an inductor's magnetic field would be strong enough? Or am I going to have to build an electromagnet? If it helps to know I am trying to send data wirelessly by turning a magnetic field on and off and tripping the sensor on the other side to pulse out RS232 data.

**EDIT:**
Current: Needs to be no more than 30mA.
Distance: A 4mm air gap.
Minimum data rate: Around 256Bits/second.
Size: Needs to be as small as possible.(Must fit into 5x10x5mm spot)
Cost: Looking to keep it under $1.50

**EDIT2:**
It is Unidirectional - 
30mA transmit - 
for now I don't really care how much it costs. I just need to get it working

**EDIT3:**
Okay. I have decided to do it optically. Does anyone known where I can get an IR detector in the 1.5micron range?(Should I move this to a new question?)

[Actual data sheet here](http://www.allegromicro.com/en/Products/Part_Numbers/3212/3212.pdf)