DSPI driver example for TWR-K21F120M not outputting anything on TWRPI socket

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DSPI driver example for TWR-K21F120M not outputting anything on TWRPI socket

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dagan_martinez
Contributor I

Hi!

 I am running the example "dspi_polling_b2b_transfer_master.c" and several other of the DSPI examples. 

I have an oscilloscope attached to pins 12(CLK) and 11(SS) of the J3 TWRPI socket. When I run the example, nothing shows on the scope. 

I get this as output:

`DSPI board to board polling example.
This example use one board as master and another as slave.
Master uses polling way and slave uses interrupt way.
Please make sure you make the correct line connection. Basically, the connection is:
DSPI_master -- DSPI_slave   
   CLK      --    CLK  
   PCS      --    PCS
   SOUT     --    SIN  
   SIN      --    SOUT
   GND      --    GND

 Master transmit:


Error occured in DSPI transfer !

 Press any key to run again`  (I removed the print statements in the loop after "Master transmit") 

When I do anything with I2C, I *do* get output shown on the oscilloscope. So what's up with DSPI?

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danielchen
NXP TechSupport
NXP TechSupport

Hi Dagan:

In this example , we need two boards, one board used as DSPI master and another board used as DSPI slave.

I would suggest you double check the board settings first

Note: Please separate the connected wires, if not, mixed wires may caused
      electromagnetic interference and data will transfer error.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Master Board                            Slave Board
INSTANCE0(SPI0)     CONNECTS TO         INSTANCE1(SPI0)
Pin Name   Board Location     Pin Name  Board Location
SIN          A-77              SOUT       A-76
SOUT         A-76              SIN        A-77
SCK          B-48              SCK        B-48
PCS0         B-46              PCS0       B-46
GND          B-2               GND        B-2
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Please refer to the readme file on this folder for more details

SDK_2.3.1_TWR-K21F120M\boards\twrk21f120m\driver_examples\dspi\polling_b2b_transfer\master\

Regards

Daniel

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dagan_martinez
Contributor I

Hi Daniel,

Even if I don't have a second board attached, I should still see the clock on the oscilloscope, right? I have it set to trigger at a voltage change

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danielchen
NXP TechSupport
NXP TechSupport

Hi Dagan:

You can see the master clock only when you are sending the data.  The clock is NOT always on.

Regards

Daniel

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