Background:
I am developing an app which sends an SMS to users after registration payment. The SMS text is sending to the mobile phone fine, but the currency symbol is not appearing properly.
I am testing content like this
$smsContent = "This is a euro test mesage 1) € 2) € 3) €";
But nothing works.
You have to encode the content properly with GSM7 charset.
You can search for some already existent library, patch PHP to make iconv() work with it or even try to convert the PHP patch code into PHP:
http://mobiletidings.com/2009/07/06/gsm-7-encoding-gnu-libiconv/