Re: High speed GPIO operations
Posted: Thu Jan 05, 2017 1:57 pm
by ESP_igrr
No, that's a bug. Thanks for pointing this out. We'll have a fix shortly.
Re: High speed GPIO operations
Posted: Wed Jan 18, 2017 4:01 pm
by raz123
Is the ESP32's GPIO speed spec available in any document?
On ESP8266, after testing with direct ASM toggling, the GPIO turned out to be limited to 6 Mhz. See:
http://imgur.com/FzdnY5X
Re: High speed GPIO operations
Posted: Thu Jan 19, 2017 3:58 am
by kolban
Raz123,
If I may ask, what kind of project are you looking at that needs such high I/O rates?
If have had good luck using the RMT peripheral APIs and subsystem. As best I can understand it, one specifies the output pattern (high for how long and low for how long) as a sequence of records and then hands that off to the RMT component. The RMT component then uses hardware to output those signals with no further application logic involved. Ive been seeing as high a granularity as needed ... one specifies "clock ticks" in clock units with a maximum resolution of 80MHz but Ive been using a divider factor of 8 to give me a granularity of 10MHz. Ive been using this for Neopixels/WS2812 LEDs.