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Feather I/O to TTL: Logic
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Feather I/O to TTL: Logic

by doctorwho8 on Sun Jun 26, 2022 1:40 am

Hello!
Would I be correct in believing that the basic Feather, such as one of the Huzzah ESP8266 designs which has an output of 3.3V can be arranged to use the Level Converter to connect to TTL logic? That stuff runs at 5.5 volt levels, and the discussion is running away from these forums if the regular ESP8266 is indeed 5v tolerant or it needs appropriate level conversion.

The same idea of course also applies to the Feather Basic 32U4 Proto board of course, but currently I've got an idea taking shape to allow my regular logic designs to accept things from WiFi and the ESP8266 seemed almost like a good choice.

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Re: Feather I/O to TTL: Logic

by Franklin97355 on Sun Jun 26, 2022 2:35 am

This might help you understand TTL

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Re: Feather I/O to TTL: Logic

by doctorwho8 on Sun Jun 26, 2022 12:00 pm

Franklin97355 wrote:This might help you understand TTL


Hello!
It would, if I hadn't seen it before. I've also been using TTL logic for a long while. It's these 3.3v WiFi hardware examples that I'm concerned with. Now in looking at the pages on this example from the learning area for the Huzzah https://learn.adafruit.com/adafruit-feather-huzzah-esp8266?view=all I came across this blurb:
"The TX pin is the output from the module and is 3.3V logic.

The RX pin is the input into the module and is 5V compliant (there is a level shifter on this pin)

These are connected through to the CP2104 USB-to-Serial converter so they should not be connected to or used unless you're super sure you want to because you will also be getting the USB traffic on these!" That comes up below the box on the serial I/O area. It confirms that the RX pin is indeed 5v compliant. The TX pin isn't, but since that's not what this prototype is interested in, it is the RX pin that's doing it, I'm good. But for later work, my first posting brought up the rest of this. It would be interesting to compare these Feather Huzzah boards to the ones from Parallax, such as https://www.parallax.com/product/parallax-wx-esp8266-wifi-module-sip/ Which is indeed the "Parallax WX ESP8266 WiFi Module - SIP" admittedly the big difference is that there's a full serial port on them, whereas the Feather does not. Given that the two boards work in different environments, it's not a big thing.

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