Problem with I2C on KL27

juancamilomonto — Fri, 29 May 2015 03:07:24 GMT

Hi,

Im working with the KL27 and the protocol I2C to read the data of the BMT180, but when I send the dares (0xF4) it changes the MSB and sends 0x74.

I don't know which the problem is because my code is very simple.

Im using de function of SendDataPolling on KDS

Regards,

Juan Camilo Montoya

Re: Problem with I2C on KL27

Jorge_Gonzalez — Wed, 03 Jun 2015 22:53:52 GMT

Hello Juan Montoya:

Please notice the I2C standard address is 7-bits long, so from an 8-bit address value (in this case 0xF4) the most significant bit is discarded and the value is shifted 1 position to the left to accommodate the R/W bit in the less significant bit of the first frame sent by the I2C master, such as next:

| ADD6 | ADD5 | ADD4 | ADD3 | ADD2 | ADD1 | ADD0 | R/W |

I think this is why you see it as 0x74. Please let me know if this is not your problem.

Regards!,
Jorge Gonzalez

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Problem with I2C on KL27

Re: Problem with I2C on KL27