Example project LPI2C_MASTER

[hajianik]

Hi,

For the LPI2C_MASTER project , I don't seem to understand the wiring connection. for S32K44EVB-Q100 the following describes the wiring:

PIN FUNCTION | S32K144EVB-Q100 | S32K144-MB
    ----------------|---------------|--------------
    LPI2C SCL (\b PTA3) |J1-3 - Slave SCL      |J9-30 - Slave SCL
    LPI2C SDA (\b PTA2) |J1-1 - Slave SDA    |J9-29 - Slave SDA
    GND       (\b GND)  |J3-11 - Slave GND    |J6 - Slave GND

So PTA3/PTA2 where are they connected to, don't we need a pull up on SCL(PTA3)?

[peter09]

please uplode working example of lpi2c master for s32k144evb bord

[danielmartynek · Accepted solution]

Hi,

These pins PTA2/PTA3 are connected only to the J1 header.

Pin configuration of this example is set in 2-pin open drain mode (see register MCFGR1) which requires pull-ups. Internal pull-ups are enabled by default (PORTA[PCR]) so you can see the communication on scope. It might work but in general these internal pull-ups are week for I2C communication so you should use external pull-ups.

Regards,

Daniel

[hajianik]

Thanks for your reply

So there is actually no Slave device, So who is sending ACK and other frames from Slave. Or this is just sending 255 bytes in one shot with one stop at the end without receiving any thing from any slave?

Thanks,

Koorosh Hajiani

[danielmartynek]

Hi,

Yes, that's correct. The S32K144 device has only one LPI2C instance. So you need two boards, one as a master and one as a slave, or another I2C device.

Regards,

Daniel