NRF52_MBED_TimerInterrupt LibraryHow To Install Using Arduino Library ManagerThis library enables you to use Interrupt from Hardware Timers on an an NRF52-based board using mbed-RTOS such as Nano-33-BLE.. It now enables you to use up to
16 different ISR-based timers, while actually consuming only
1 Hardware Timer. Timers' interval is very long (ulong millisecs). The most important feature is they're ISR-based timers. Therefore, their executions are not blocked by bad-behaving functions or tasks. This important feature is absolutely necessary for mission-critical tasks.
Why do we need this NRF52_MBED_TimerInterrupt LibraryImagine you have a system with a
mission-critical function, measuring water level and control the sump pump or doing something much more important. You normally use a
software timer to poll, or even place the function in loop(). But what if another function is blocking the loop() or setup().
So your function might not be executed, and the result would be disastrous.
You'd prefer to have your function called, no matter what happening with other functions (busy loop, bug, etc.).
The correct choice is to use a
Hardware Timer with Interrupt to call your function.
These hardware timers, using interrupt, still work even if other functions are blocking. Moreover, they are much more precise (certainly depending on clock frequency accuracy) than other software timers using millis() or micros(). That's necessary if you need to measure some data requiring better accuracy.
Functions using normal software timers, relying on loop() and calling millis(), won't work if the loop() or setup() is blocked by certain operation. For example, certain function is blocking while it's connecting to WiFi or some services.
The catch is your function is now part of an
ISR (Interrupt Service Routine), must be
lean and mean, and follow certain rules. More to read on:
HOWTO Attach InterruptImportant Notes:1. Inside the ISR function,
delay() won't work and the value returned by
millis() will not increment. Serial data received while in the ISR function may be lost. You should declare as
volatile any variables that you modify within the attached function.
2. Typically global variables are used to pass data between an ISR and the main program. To make sure
variables shared between an ISR and the main program are updated correctly, declare them as
volatile.
Releases v1.0.11. Initial coding for Nano-33-BLE and sync with
NRF52_TimerInterrupt LibrarySupported Boards -
Arduino Nano-33-BLE.
Examples: 1.
Argument_None 1.
ISR_16_Timers_Array 3.
SwitchDebounce 4.
TimerInterruptTest 5.
TimerInterruptLEDDemo