Try answer this for me: I need to replace a spark-plug (I think) in my cars engine. The car is (mostly) blue and has 4 tires. How to proceed?
Get the hint? 
On this rare occasion I might have to correct you Pete! 
While pampering my first born I found out that my UNO has a serial buffer!! 
Trial and error made me abandon interrupts since it didn’t work well with Blynk. As long it’s “real” data and not a boolean value your’e getting, a semi-fast timer might do the trick!
But it all depends on what kinda car you drive 