topic DSPI driver example for TWR-K21F120M not outputting anything on TWRPI socket in Kinetis Microcontrollers

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

dagan_martinez — Tue, 11 Dec 2018 21:12:20 GMT

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?

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

danielchen — Wed, 12 Dec 2018 08:38:02 GMT

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

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

dagan_martinez — Wed, 12 Dec 2018 14:03:46 GMT

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

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

danielchen — Fri, 14 Dec 2018 07:23:18 GMT

Hi Dagan:

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

Regards

Daniel