For those of you wondering what this is about here is a link to a great site on software defined radio.
http://www.rtl-sdr.com/rtl-sdr-radio-scanner-tutorial-receiving-airplane-data-with-acars/
You can receive ACARS and track planes using PogoPlug with a really cheap USB receiver. You can buy this USB stick for $8 to $20 on Ebay .
I have re-written acarsdec by Thierry Leconte to use mostly integer math on ARM5 that does not have FPU.
Original software is here on SourceForge https://sourceforge.net/projects/acarsdec/
Original version can do only one ACARS channel at a time on PogoPlug Mobile with very high CPU load. Mine is overclocked to 1GHz so I am not even sure if acarsdec would even work with default clock of 800MHz.
In fact, people complain that even on Raspberry Pi only 3 channels with high CPU load are possible.
Anyway, I would be interested to hear how this works for you so that I could tweak the code.
This version is coded for 4 channels max and 2.5MHz sampling rate. It seems to decode most of the messages with about 38% CPU load ( vs. 90% of original one with one channel and 1MHz sampling rate) but I had no chance to compare it side by side to acarsdec on a decent machine with Intel CPU. It may drop some messages due to reduced accuracy of integer trig compared to float.
I would really appreciate your feedback. Please, please try it and comment on the code if you can. I have added source code to the updated version on 04/06/2016
Updated source code and working binary is published on
https://sourceforge.net/projects/acarsdec-int/