mad_dad

I2C Master and multiple slaves using Freescale Demo boards

Discussion created by mad_dad on Jul 8, 2008
Latest reply on Jul 10, 2008 by mad_dad
I have a number of Freescale demo boards DEMO9S08AW60 and I am trying to implemet a Master to multiple slaves interface using the I2C (a bit like a 1553 bus). Although I can connect a master to a slave directly with bus pull up resistors and it works fine, if I connect another slave to the bus the whole bus locks up. Holding all the slaves bar one in reset allows the bus to work, i assume the SDA and CLK lines are tri-state on reset.
Is it OK to connect the MCU I2C directly together or do I need some sort of bi-directional buffer for each slave?

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