I want to interface 5V pins to a 3.3V XBee radio and am looking for the most robust way to do it.
I was going to follow the diode solution in SparkFun’s [sensor interfacing tutorial, though I realized another solution could be putting a 1.8V zener diode (like [this one) in series in the data line.
http://i.imgur.com/PTvqd.jpg
Is the above design sound? What are the caveats I need to keep in mind if I use this setup vs the (normal) diode solution?](http://www.digikey.com/product-detail/en/TZS4678-GS08/TZS4678-GS08CT-ND/3104522)](http://www.sparkfun.com/tutorials/65)
I think [this be a better solution. Stock a few for other projects and you never have to worry about 3v3 or 5v parts playing nice together. Or, use their example as a reference and build your own.](https://www.sparkfun.com/products/8745)
Replacing a regular diode with a zener diode in your application would not gain you anything. A zener diode is a special diode that stops reverse voltages up to the rated voltage, once the voltage exceeds the rated voltage then the diode allows current flow through. Zeners are typically used as voltage references because of this action. You would be better off using a high speed switching diode in this application. You also need to make sure there is a pull up to 3.3V on the XBEE side.
WethaGuy: So you’re suggesting the third option in the article I posted? This will be for a finished PCB, by the way, so I can’t use a breakout board device, but I’ll consider building that into my design. Thanks.
falingtrea:
You would be better off using a high speed switching diode in this application. You also need to make sure there is a pull up to 3.3V on the XBEE side.
So... basically that's the second solution I was talking about in my OP?
I don’t think this will help you. A zener diode isn’t going to make wonders here. From the looks of it, your project doesn’t require a voltage referencing device. I will post more on this as soon as possible. Thank you!
