Compatibility and IRQ fixed for waveform/tone/pwm#4872

Merged

devyte merged 3 commits intoesp8266:masterfrom

earlephilhower:clifix

Jul 2, 2018

Commits on Jul 1, 2018

Commits on Jul 2, 2018

Fix tone(int,int,int) infinite loop
earlephilhower
committed