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connect Arduino to BIII through I2C not working
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bigpanda  
#1 Posted : Sunday, June 10, 2012 12:21:57 PM(UTC)
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I am using Arduino Mega2560, connect digital pin 20 to BIII SDA and pin 21 to BIII SCL and GRN to GRN with simple 10K-10K voltage divider. I found that there is always 3.3V at BIII SDA & SCL pins and signals from Arduino are pulled high. Have I done anything wrong?
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Corpius  
#2 Posted : Sunday, June 10, 2012 12:43:30 PM(UTC)
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are you using the Hifiduino code? If so, then it should be connected like this:

I2C connection and level converter hookup
http://ce-designs.net/
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bigpanda  
#3 Posted : Sunday, June 10, 2012 1:54:12 PM(UTC)
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Thanks Corpius

I remember Brian mentioned in Diyaudio that a simple resistor divider will do the job, not necessary to use the level convertor. The problem is why there is 3.3V present on the two pins (SDA & SCL) on BIII.
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Russ White  
#4 Posted : Sunday, June 10, 2012 5:39:33 PM(UTC)
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No you would not use a voltage divider here. That advice was not related to I2C.

You need to read up on I2C, the 3.3V is normal state for an idle bus.

The level shifter for I2C is a good idea, though it's necessity depends on the bus master implementation. Open drain types won''t need it.
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thanks 1 user thanked Russ White for this useful post.
bigpanda on 6/11/2012(UTC)
Bemused  
#5 Posted : Wednesday, June 13, 2012 11:29:29 AM(UTC)
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I have an Arduino Uno r3 connected via I2C to a Buffalo-III using Hifiduino code without the level converter.
Al seems fine.

Tony
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bigpanda  
#6 Posted : Thursday, June 14, 2012 7:12:27 AM(UTC)
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I bought a level convertor from China and it works fine. Problem solved.
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