[ERROR] Controlling Other Pucks

On recent firmwares you can save any uncaught exceptions like this:

>process.on('uncaughtException', function(e) { require("Storage").write("error",e); });
=undefined
>^*&^*&678^* &^*&
>print(require("Storage").read("error"))
{"message":"Got '^' expected EOF","type":"SyntaxError","stack":" at line 1 col 1\n^*&^*&678^* &^*&\n^\n"}

Note that with the uncaughtException handler set, you no longer get exceptions reported to the console!

However that's not ideal as it's possible you got a message that wasn't an exception... So you can do something like this:

// Dump the data we had
function showLog() {
  print("=========================");
  print(require("Storage").read("log"));
  print("=========================");
}
// When we get new data from the console, stick it into flash 
LoopbackB.on('data',function(d) {
  var log = require("Storage").read("log");
  if (log) log+=d; else log=d;
  if (log.length>1000) log=log.substr(-1000);
  require("Storage").write("log",log);  
});
/* When we disconnect from Bluetooth, put the console
onto loopback. It should automatically return next time
we leave */
NRF.on('disconnect', function(reason) { 
  LoopbackA.setConsole();
});

Although be careful with that as it'll write a lot of data to flash every time anything gets printed - so if you have a lot of print statements it'll be really slow and will wear out the flash memory.

Finally your other option is just to attach wires to the second device: http://www.espruino.com/Puck.js#serial-console