Avoid unnecessary waveform de-initialization #4913
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Remove and rewrite all the parts of the core/libraries using TIMER1 and consolidate into a single, shared waveform generation interrupt structure. Tone, analogWrite(), Servo all now just call into this shared resource to perform their tasks so are all compatible and can be used simultaneously. This setup enables multiple tones, analogWrites, servos, and stepper motors to be controlled with reasonable accuracy. It uses both TIMER1 and the internal ESP cycle counter to handle timing of waveform edges. TIMER1 is used in non-reload mode and only edges cause interrupts. The interrupt is started and stopped as required, minimizing overhead when these features are not being used. A generic "startWaveform(pin, high-US, low-US, runtime-US)" and "stopWaveform(pin)" allow for further types of interfaces. Minimum high or low period is ~1 us. Add a tone(float) method, useful when working with lower frequencies. Fixes #4321. Fixes 4349.
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Looks good to me, thanks! Like I was mentioning in the original discussion, we may want to remove the Also, we could move the We could also set up an inverse map and make this O(1) for pin->waveform entry. No for needed then. If the SWSerial still has issues, let's try some of these. |
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After posting PR, I noticed that by adding on the very start of Just removing |
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@earlephilhower looks good! |
which harms frequent digitalRead/Write like SoftwareSerial.