I am doing some research into smart devices. I realized that the device is communicating with an Internet end-point but the communication is encrypted (and using a proxy tool doesn't work).
J2 looks suspiciously close to the classic ARM 20-pin JTAG connector
Well, the fastest way is get datasheet of MCU and test data pins for get JTAG access and dump main code from RAM. Also you can measure pin volts looking for 3.3v and place Rx and Tx rs232 for get console.
Else if you dont have JTAG access you should start to think about desolder flash chip (in case it exists) but in this case the code seems to be written into flash area of the MCU.
So finally successful depends on IC security...Maybe some some glitch at the right place and moment could help as well..