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MPR121 datasheet and app note give wrong i2c slave address (rev 0, 9/2009)

Question asked by Robert Imhoff on Feb 21, 2010
Latest reply on Jan 18, 2012 by Rich Testardi

Hello,

 

if anyone else tries out the MPR121 touch sensor controler, I wanted to save them some frustrating hours by pointing out the both the MPR121 datasheet and the i2c communication application note AN3895  (both currently at Rev 0, 9/2009) give the wrong i2c slave address for this part.

 

When the address select line is tied to ground, the correct slave address is 0x5a (and not 0x4D). I imagine the other three options (address select tied to Vcc or SDA or SCL are similarly wrong and should all be shifted to 0x59, 0x5b, 0x5c).

 

Otherwise the controller works fine and is simpler to configure than the AD7147.

 

Best regards,

Robert

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