New to the Arduino, though I've had one for a year or so on a 3D printer, but never needed to code...
I want to have a sensor (MQ series) showing its results on an LCD bar-graph & sounder but I'd like to incorporate an RFID (13.56) reader for security.
I propose to switch the device on and be prompted for an authorised RFID tag to proceed, once one has been produced it will then go into its sensing mode.
Does this all sound reasonable? 
Does this all sound reasonable?
Yes, very.
Grumpy_Mike:
Does this all sound reasonable?
Yes, very.
Cheers for the quick reply, I'm on the hunt for some analogue signal to bar graph code. It's all double Dutch so far! 
I'm on the hunt for some analogue signal to bar graph code.
The analog signal (you foreigners spell things funny 8)) will be converted to a value between 0 and 1023. Mapping that value to a number of bars/LEDs/whatevers is trivial.
Making those bars/LEDs/whatevers light up (and any others turn off) is equally trivial.
What part are you having difficulties with?
PaulS:
I'm on the hunt for some analogue signal to bar graph code.
The analog signal (you foreigners spell things funny 8)) will be converted to a value between 0 and 1023. Mapping that value to a number of bars/LEDs/whatevers is trivial.
Making those bars/LEDs/whatevers light up (and any others turn off) is equally trivial.
What part are you having difficulties with?
Cheers, more the feasibility part than an issue, I'm sure they will be along soon enough!