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Ok so following on from my previous post here. I have decided to start with the Wiegand wiring interface. I've drawn a diagram below to illustrate how I plan to wire everything up. Would appreciate if any guru can take a look and comment on any mistakes or improvements please. The CD4050BE chip is used to step down the voltage from 5V (coming out of D1/D0) to 3.3V (to the Pi GPIO pins).

One area which I am a little unsure of are my GND connections. Any guidance (or validation) in that specific area would be great as well.

Apologies for the over simplistic line diagram.

EDIT: For the relay, I am using a relay board similar to this. This isn't drawn to detail in the diagram.

enter image description here

fabbbles
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1 Answers1

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CD4050B will step the voltage down to VCC (5V), and you need to step it down to 3.3V GPIO level, so it should be connected to 3.3V pin of the Pi instead of 5V. ICs from Texas Instruments accept VCC between 3 and 18V, so powering with 3.3V is OK.

Dmitry Grigoryev
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