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Add lead paragraph to state "single thread" premise.
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JRobert
JRobert
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Since you put "simultaneous" in quotes, I'm assuming you realize that one MCU can only do one thing at a time, but cleverly programmed, it can do small pieces of several things faster than you and I can perceive the difference. (I state this for completeness, for the benefit of readers who may not have thought this out yet.)

A couple of techniques will help you here.

One is what I call "maybedo" functions - functions you call frequently, that do something or nothingdo not do something (depending on conditions such as time or input signals) but they do it quickly and return immediately. See my answer here for more explanation of "maybedo" functions.

Another and very important one is to avoid delay() calls. Try a timer library such as SimpleTimer. This lets your loop() function and those it calls, keep short. The SimpleTimer library entry is a "maybedo" for up to 10 timer-driven functions. All you have to do is call mytimers.run() frequently. Mostly it won't do much, but occasionally it will find one or more timers have expired and will call their associated functions for you. You just have to have set up the timers to call some simple - and again, short - functions to do something. And to be clear, we're talking about software-based timers, not the MCU's hardware timers. The library's work is based on the millis() function, but it automates that for you.

A couple of techniques will help you here.

One is what I call "maybedo" functions - functions you call frequently, that do something or nothing (depending on conditions such as time or input signals) but they do it quickly and return immediately. See my answer here for more explanation of "maybedo" functions.

Another and very important one is to avoid delay() calls. Try a timer library such as SimpleTimer. This lets your loop() function and those it calls, keep short. The SimpleTimer library entry is a "maybedo" for up to 10 timer-driven functions. All you have to do is call mytimers.run() frequently. Mostly it won't do much, but occasionally it will find one or more timers have expired and will call their associated functions for you. You just have to have set up the timers to call some simple - and again, short - functions to do something. And to be clear, we're talking about software-based timers, not the MCU's hardware timers. The library's work is based on the millis() function, but it automates that for you.

Since you put "simultaneous" in quotes, I'm assuming you realize that one MCU can only do one thing at a time, but cleverly programmed, it can do small pieces of several things faster than you and I can perceive the difference. (I state this for completeness, for the benefit of readers who may not have thought this out yet.)

A couple of techniques will help you here.

One is what I call "maybedo" functions - functions you call frequently, that do or do not do something (depending on conditions such as time or input signals) but they do it quickly and return immediately. See my answer here for more explanation of "maybedo" functions.

Another and very important one is to avoid delay() calls. Try a timer library such as SimpleTimer. This lets your loop() function and those it calls, keep short. The SimpleTimer library entry is a "maybedo" for up to 10 timer-driven functions. All you have to do is call mytimers.run() frequently. Mostly it won't do much, but occasionally it will find one or more timers have expired and will call their associated functions for you. You just have to have set up the timers to call some simple - and again, short - functions to do something. And to be clear, we're talking about software-based timers, not the MCU's hardware timers. The library's work is based on the millis() function, but it automates that for you.

Source Link
JRobert
JRobert
  • 15.4k
  • 3
  • 25
  • 53

A couple of techniques will help you here.

One is what I call "maybedo" functions - functions you call frequently, that do something or nothing (depending on conditions such as time or input signals) but they do it quickly and return immediately. See my answer here for more explanation of "maybedo" functions.

Another and very important one is to avoid delay() calls. Try a timer library such as SimpleTimer. This lets your loop() function and those it calls, keep short. The SimpleTimer library entry is a "maybedo" for up to 10 timer-driven functions. All you have to do is call mytimers.run() frequently. Mostly it won't do much, but occasionally it will find one or more timers have expired and will call their associated functions for you. You just have to have set up the timers to call some simple - and again, short - functions to do something. And to be clear, we're talking about software-based timers, not the MCU's hardware timers. The library's work is based on the millis() function, but it automates that for you.