GPIO Expander Bonnett in place of 74AHCT125

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Percival
 
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Joined: Fri Mar 27, 2020 4:35 pm

GPIO Expander Bonnett in place of 74AHCT125

Post by Percival »

Hello all - I am in the process of buying some components for a new project and really just need a sanity check that these components will work.

I'm trying to run the NeoPixel ring (this one specifically, https://www.adafruit.com/product/1586) and a Pimoroni Skywriter on a Raspberry Pi Zero W. I've already confirmed that there are no pin clashes between these two, but as some of you may already know there are issues with using Pis and Neopixels due to the 5V requirement and data signal timing.

I dug up this guide (https://learn.adafruit.com/neopixels-on ... -pi-wiring) from some years ago that suggests using a 74AHCT125 as a level converter, however I just want to confirm that the GPIO Expander Bonnett (https://www.adafruit.com/product/4132) would solve the same problem and also obviate the need for a breadboard.

Here again is a list of all the main components:

Raspberry PI Zero W
Skywriter HAT: https://www.adafruit.com/product/2325
NeoPixel Ring: https://www.adafruit.com/product/1586
GPIO Expander Bonnett: https://www.adafruit.com/product/4132

Thank you very much in advance for an responses, and please let me know if there are any clarifying points I left off.

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kattni
 
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Joined: Fri Aug 18, 2017 6:33 pm

Re: GPIO Expander Bonnett in place of 74AHCT125

Post by kattni »

No. GPIO expanders can never run NeoPixels. You will need a level shifter designed to work with NeoPixels.

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