First, wanted to say thanks for this project, just what I was looking for the upgrade my ADT alarm system.

I was compiling the arduino code, and was getting this error
SmartThings smartthing(HW_SERIAL3, messageCallout); //constructor for hardware serial port with ST_Anything Library
exit status 1
‘messageCallout’ was not declared in this scope

I searched, and found that if I add this line before the line that causes the error, it fixes the compilation error
SmartThingsCallout_t messageCallout; // call out function forward declaration

It was from here

It would be nice to fix the code, and hoping this helps someone else. Not sure why everyone doesn’t have this problem?

I am doing this on a mac, I wouldn’t think it would matter.

I was also wondering if anyone has integrated this with ST_Anything?

I’m planning to do integrate both, so I can integrate my alarm with Smartthings, and add a garage door sensor/opener to the mix.