topic Re: Freedom Kl46Z i2c in Kinetis Software Development Kit

Freedom Kl46Z i2c

OROZO — Fri, 06 Nov 2015 04:16:00 GMT

Hello every body,

I'm trying to implement an i2c communication between the FRDM-KL46Z and the MMA8451Q accelerometer but unfortunetly I don't understand the KSDK ver 1.3 API Reference Manual (I think traditional PExpert was a lot more helpful), so I want to know somebody who can explain me the following function:

i2c_status_t I2C_DRV_MasterSendDataBlocking ( uint32_t instance, const

i2c_device_t device, const uint8_t cmdBuff, uint32_t cmdSize, const uint8_t

txBuff, uint32_t txSize, uint32_t timeout_ms )

I don't understand the cmdBuff purpouse, what kind of information should be filled in? I think the txBuff already contains the bytes to be transmitted to the slave.

The only way this function returns a succesful flag is with cmdBuff = NULL an cmd size = 0.

Another issue is that the MMA8451Q manual explain the need of a Repeated Start, and as I bealive there is no way to do that with the standar i2c API, or at least I have no idea how to do that.

I think the KSDK API reference manual could be done a lot better by freescale.

Re: Freedom Kl46Z i2c

Alice_Yang — Fri, 06 Nov 2015 08:48:22 GMT

Hello Oscar,

These two parameters are about the slave register you wan to write.
“cmdBuff” is the address of the slave register , the size is the size of slave register (for example , if the register is 1byte , the here you can write 1).
How to configure these two parameters you need Check the Reference manual of MMA8451Q .

Hope it helps

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Have a great day,
Alice

Re: Freedom Kl46Z i2c

OROZO — Fri, 06 Nov 2015 15:54:30 GMT

Thank you Alice,

I'm going to try to implement the function again this weekend.