I have a routine in my main program file for displaying float values on terminal program. When i try to use the same routine in my Interrupt service routine(ISR), it give an warning stating "Reference made to unresolved function". Secondly i also wanted to know how can i use a global variable in the ISR as its not possible to pass a parameter from any routine to the ISR.
"A global variable shared between an ISR and main code should be declared volatile." Note that this is in addition to Hans-Bernhard & Erik's notes about "atomic" accesses - not an alternative!