In this post I will continue what I started in the previous post in which I presented how to import and prepare Ghidra to analyze the Biot Tracer firmware, whose circuit was also reversed engineered.
The Briot Tracer is used as an example to show (at least partially) the firmware reverse engineering process. Since it uses an external memory (EPROM) the process for obtaining the firmware is simple which makes it ideal as a test case.
As it is not the purpose of this post to study the complete firmware, only the RS232 communication is analyzed in order to gain some insight into how this communication occurs.