Regarding the interrupts ("InterruptIn", defined as external signal in the handbook), and timers (more specifically, the "Ticker" function).

If an interrupt happens during a function call caused by the ticker event, which one will take priority (the interrupt, or the function call)?  

--> I would like to use the InterruptIn function to accept user inputs, but I need the ticker function (and the function attached to it) to always take priority over any user input (the interrupt would simply wait until the ticker function [and the attached function] is complete).  Is there a way to do this?  

Example running the mbed Tickers at a lower priority

1. include "mbed.h"

volatile int counter = 0; void timing_critical() { counter++; }

void long_event() { wait_ms(50); }

PwmOut out(p25); InterruptIn in(p26); Ticker tick;

int main() { out.period_ms(10); out.pulsewidth_ms(5); in.rise(&timing_critical);

printf("1) InterruptIn only...\n"); for(int i=0; i<5; i++) { counter = 0; wait(1); printf("counts/sec = %d\n", counter); }

tick.attach(&long_event, 0.1);

printf("2) InterruptIn plus long running occasional ticker event...\n"); for(int i=0; i<5; i++) { counter = 0; wait(1); printf("count/sec = %d\n", counter); }

printf("3) InterruptIn plus long running occasional ticker event at lower priority...\n"); NVIC_SetPriority(TIMER3_IRQn, 255); set mbed tickers to lower priority than other things for(int i=0; i<5; i++) { counter = 0; wait(1); printf("counter = %d\n", counter); } }