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Author Topic: Logic level converter help [Solved]  (Read 728 times)
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Salt Lake City
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Hi all,

I am trying to interface a bmp085 breakout (from Sparkfun) with an Arduino Mega.  The sensor works fine with a 3.3V supply and connected straight to SDA and SCL but the trouble comes when I try to use the sensor with a logic level converter (also from sparkfun).  The sensor sends the data but it's completely wrong.  I did a simple test where I turned a digital pin on and off through the logic level converter and a resistor and the voltage on the low side of the converter was around 2.2 Volts.  I was expecting it to be somewhere around 3.3 V.  Did I fry the logic level converter or is that within its tolerances? The only reason I'm bothering with a logic level converter is because I will need to use 5V I2C devices on the same bus.

I have included a picture of my setup

Thanks in advance for any help or advice!


* BMP085 & LLC.png (112 KB, 616x614 - viewed 13 times.)
« Last Edit: January 16, 2012, 05:55:33 pm by madvoid » Logged

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Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law.
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I2C signals are bidirectional. This means you have to use a Tx channel for each of the two signals, not one Tx and one Rx channel.
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Salt Lake City
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Wow, that was a lot simpler solution than I thought it would be. I'm sorry for asking such an obvious question, thank you very much for your help!
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