High speed GPIO operations

ESP_igrr
Posts: 2071
Joined: Tue Dec 01, 2015 8:37 am

Re: High speed GPIO operations

Postby ESP_igrr » Thu Jan 05, 2017 1:57 pm

No, that's a bug. Thanks for pointing this out. We'll have a fix shortly.

raz123
Posts: 1
Joined: Wed Jan 18, 2017 3:58 pm

Re: High speed GPIO operations

Postby raz123 » Wed Jan 18, 2017 4:01 pm

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

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kolban
Posts: 1683
Joined: Mon Nov 16, 2015 4:43 pm
Location: Texas, USA

Re: High speed GPIO operations

Postby kolban » Thu Jan 19, 2017 3:58 am

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.
Free book on ESP32 available here: https://leanpub.com/kolban-ESP32

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