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tttapa / ESP8266

Documentation and help with the ESP8266 chip/boards/modules
GNU General Public License v3.0
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It can be used in both Slave and Master mode (in software). #15

Open svofski opened 6 years ago

svofski commented 6 years ago

I think this phrase is very vague. What does "(in software)" mean here? Does it mean that SPI is bit-banged (the paragraph about I2C above used "in software" in this meaning but is clear there), or is only one of the two modes bit-banged, or does it just refer to the fact that SPI is exposed to the user?

Fantastic guide BTW, thank you so much for putting it together!

tttapa commented 6 years ago

The early versions of the datasheet talk about HSPI as an SPI slave only, saying "SPI mode can be implemented via software programming." Newer versions say it's "Slave/Master". Afaik, it's probably mostly hardware, so I'll just leave out the "in software" in the next revision.
Thank you for the feedback!

svofski commented 6 years ago

Is there a datasheet we can reliably refer to, or does it come from studying SDK or UDK? I'm just 2 days into esp8266 world and finding the information seems to be a bit chaotic task, lots of slightly contradictory bits all over the place.

From what I can see in the Arduino core source, the SPI master is implemented in hardware.