CCS/LAUNCHXL-F28379D: Transmitting SPI Data from one Launchpad to another

Tyler Ambrico

Part Number: LAUNCHXL-F28379D
Other Parts Discussed in Thread: CONTROLSUITE, C2000WARE

Tool/software: Code Composer Studio

Hello,

I'm trying to use the example code "spi_loopback_cpu1" in ControlSuite to transmit a simple integer via SPI pins. The only modification I made to this code is to transmit the number 20 instead of zero. I initialized GPIO pins 16-19 for MOSI, MISO, CLK and STE, respectively on both of my launchpads and jumped wires between the pins (16 and 16 on launchpads 1&2 connected, etc). I then used Simulink's SPI receive function to retrieve the integer, but when running in external mode it is displaying zero because it is not receiving the data. Have I set up my hardware / software correctly to do this? Is there a way for me to check if an integer is being transmitted from the first launchpad to the MOSI pin?

Thanks,

Tyler

over 5 years ago

0 Manoj Santha Mohan over 5 years ago

TI__Guru 55700 points

Tyler,

I have never used Simulink SPI receive function. So, I really cant comment on that.

But, did you check with an oscilloscope whether SPI is indeed transmitting?

Regards,
Manoj

0 Manoj Santha Mohan over 5 years ago in reply to Manoj Santha Mohan

TI__Guru 55700 points

I haven't heard back from you in a while. Is this issue resolved?

0 Tyler Ambrico over 5 years ago in reply to Manoj Santha Mohan

Intellectual 315 points

Hi Manoj,

I checked with a scope and there is nothing being transmitted on these pins. Does the spi loopback code actually send info to a pin? If not, how could I go about writing some code in line with the SPI protocol for this board/cpu (can you at least give me a starting point?)

Thanks,

Tyler

0 Tyler Ambrico over 5 years ago in reply to Tyler Ambrico

Intellectual 315 points

I'm also confused by this code because it somehow transfers data from a transfer buffer to a receive buffer, but I'm only using one board (i.e. there is no slave, only a master). I guess that's why it's called loopback, but where is the receive buffer? I think this code is just sending data to a transfer buffer and reading the data on the receive buffer on the same cpu without actually sending signal to a pin, I don't really know though

0 Manoj Santha Mohan over 5 years ago in reply to Tyler Ambrico

TI__Guru 55700 points

Tyler,

In SPI loopback mode (SPICCR.SPILBK = 1) , SIMO and SOMI lines are connected internally. This is primarily used for testing the SPI module. You need disable this mode to see signals on oscilloscope.

Regards,
Manoj

0 Tyler Ambrico over 5 years ago in reply to Manoj Santha Mohan

Intellectual 315 points

I added the line "SpiaRegs.SPICCR.bit.SPILBK=0" in spi_init() but nothing shows up on the pins still. Did I disable loopback correctly? Do other settings need to be configured to actually send signals to pins?

0 Manoj Santha Mohan over 5 years ago in reply to Tyler Ambrico

TI__Guru 55700 points

Tyler,

Please use SPI_Boot.c file as reference.

Path: <controlSUITE>\libs\utilities\boot_rom\2806x\2806x_boot_rom_v1_1\source\
Filename: SPI_Boot.c

Regards,
Manoj

0 Tyler Ambrico over 5 years ago in reply to Manoj Santha Mohan

Intellectual 315 points

How does this help? There's like no explanation in this file. I'm not a programmer, I'm a mechanical engineer and I'm just trying to get this to work in its most basic application...

0 Manoj Santha Mohan over 5 years ago in reply to Tyler Ambrico

TI__Guru 55700 points

I have provided you working code (where SPI signals are brought out) which can be used as a reference to develop your code. Disabling SPILBK should be good enough to bring SPI signals out only if corresponding GPIO (SPI GPIOs) are configured correctly.

Regards,
Manoj

0 Tyler Ambrico over 5 years ago in reply to Manoj Santha Mohan

Intellectual 315 points

This is for f2806x series not f2837xd series

0 Manoj Santha Mohan over 5 years ago in reply to Tyler Ambrico

TI__Guru 55700 points

Yes, I know. But, from SPI perspective the configurations should be the same.

0 Tyler Ambrico over 5 years ago in reply to Manoj Santha Mohan

Intellectual 315 points

I'm trying to send an integer using spi and the control suite examples don't work for doing this. This is the most basic possible procedure -- why is this so difficult to achieve?

0 Manoj Santha Mohan over 5 years ago in reply to Tyler Ambrico

TI__Guru 55700 points

Tyler,

Did you make sure you have configured GPIO correctly as SPI pins? Also, does the launchpad use the same set of GPIOs as SPI signal?

Regards,
Manoj

0 Tyler Ambrico over 5 years ago in reply to Manoj Santha Mohan

Intellectual 315 points

I just used the InitSpiaGpio(); function which enables gpio pins 16-19. When I do this, there are no data lines or clock signals at those pins. For some reason there seems to be a data line (MOSI) on pin 33, I have no idea why. This is just a function provided by control suite, I did not modify it. I also know that this board is capable of using SPI because I can run "PM_BissC_SystemTest" which uses SPI-B just fine.

Is there a better way to set up the pins than using InitSpiaGpio?

0 Manoj Santha Mohan over 5 years ago in reply to Tyler Ambrico

TI__Guru 55700 points

GPIO33 is not even a SPI pin, so it might be some other signal. InitSpiaGpio is the right function. So, it should be fine

0 Manoj Santha Mohan over 5 years ago in reply to Manoj Santha Mohan

TI__Guru 55700 points

Also, just be on safer side i would also recommend you download C2000Ware to get latest version of this example.

0 Tyler Ambrico over 5 years ago in reply to Manoj Santha Mohan

Intellectual 315 points

I do have the latest version and clearly the function didn't work because there is nothing showing up on the scope at the initialized pins. Would it be possible to try doing this on your end to see if you can see anything on the scope?

I also tried using Simulink's SPI Transmit function with loopback disabled and I still did not see anything on the scope. None of the pins have data or clock signals. I've tried initializing pins 16-19 and 58-61 on two different boards, with two different software, and still nothing.

Yet somehow PM_BissC_SystemTest uses SPI-B correctly. Any thoughts on what's going on here?

0 Manoj Santha Mohan over 5 years ago in reply to Tyler Ambrico

TI__Guru 55700 points

Tyler,

I was able to probe SPIA signals on F28377S Launchpad successfully without modifying controlSuite code. There is nothing wrong with the code. Please check your schematics and probe signals accordingly.

Path: <C2000Ware>\boards\LaunchPads\LAUNCHXL_F28377S\

GPIO16 - J4.36
GPIO17 - J4.35
GPIO18 - J8.76
GPIO19 - J8.75

Regards,
Manoj

0 Tyler Ambrico over 5 years ago in reply to Manoj Santha Mohan

Intellectual 315 points

I have an F28379D Launchpad though. Would you be able to check on that board model for me?

0 Manoj Santha Mohan over 5 years ago in reply to Tyler Ambrico

TI__Guru 55700 points

I tested the same code on F28379D launchpad. I do see SPI signals.

GPIO16 - J4.3 (Marked as 33)
GPIO17 - Don't have direct access
GPIO18 - J1.4 (Marked as 4)
GPIO19 - J1.3 (Marked as 3)

Regards,
Manoj

0 Tyler Ambrico over 5 years ago in reply to Manoj Santha Mohan

Intellectual 315 points

Thanks for working through this with me Manoj. Would you be able to send me the exact code you used? I'm still unable to replicate what you did with pins 16-19 unfortunately. Did you keep loopback enabled?

Also, can you try setting this up for GPIO 58-61 for SPI-A on your end? 58-61 all have spi-A headers (default on the f2879d board schematic). I tried this but all my pins were just high, there were no data streams.

Thanks again,

Tyler

0 Manoj Santha Mohan over 5 years ago in reply to Tyler Ambrico

TI__Guru 55700 points

Tyler,

I used spi_loopback_cpu1 example (I didn't modify the example) as it is controlsuite (or) C2000Ware.

a) The example code already had loopback mode enabled (As I said before I didn't modify the code)
b) I probed SPIA signals in GPIO16-19 and I didn't try GPIO58-61 pin option.

Regards,
Manoj

0 Tyler Ambrico over 5 years ago in reply to Manoj Santha Mohan

Intellectual 315 points

Hi Manoj,

I've been at this for a while but I can't seem to get GPIO pins 58-61 to show anything. I set up the mux

    GpioCtrlRegs.GPBMUX2.bit.GPIO58 = 15; // Configure GPIO16 as SPISIMOA
// GpioCtrlRegs.GPAMUX1.bit.GPIO5 = 2; // Configure GPIO5 as SPISIMOA
    GpioCtrlRegs.GPBMUX2.bit.GPIO59 = 15; // Configure GPIO17 as SPISOMIA
// GpioCtrlRegs.GPAMUX1.bit.GPIO3 = 2; // Configure GPIO3 as SPISOMIA
    GpioCtrlRegs.GPBMUX2.bit.GPIO60 = 15; // Configure GPIO18 as SPICLKA
    GpioCtrlRegs.GPBMUX2.bit.GPIO61 = 15; // Configure GPIO19 as SPISTEA

with the integer 15 as per the f28379d data sheet, but this doesn't seem to do anything. Can you try to figure out how to get GPIO 58-61 working for SPI-A on your end and tell me how you did it? I am out of ideas.

Thanks,

Tyler A

0 Manoj Santha Mohan over 5 years ago in reply to Tyler Ambrico

TI__Guru 55700 points

Tyler,

Here are the GPIO settings for configuring GPIO58-61 pins SPI pins.

GpioCtrlRegs.GPBPUD.bit.GPIO58 = 0; //Pull-up enabled
GpioCtrlRegs.GPBPUD.bit.GPIO59 = 0; //Pull-up enabled
GpioCtrlRegs.GPBPUD.bit.GPIO60 = 0; //Pull-up enabled
GpioCtrlRegs.GPBPUD.bit.GPIO61 = 0; //Pull-up enabled

GpioCtrlRegs.GPBGMUX2.bit.GPIO58 = 3;
GpioCtrlRegs.GPBGMUX2.bit.GPIO59 = 3;
GpioCtrlRegs.GPBGMUX2.bit.GPIO60 = 3;
GpioCtrlRegs.GPBGMUX2.bit.GPIO61 = 3;

GpioCtrlRegs.GPBMUX2.bit.GPIO58 = 3;
GpioCtrlRegs.GPBMUX2.bit.GPIO59 = 3;
GpioCtrlRegs.GPBMUX2.bit.GPIO60 = 3;
GpioCtrlRegs.GPBMUX2.bit.GPIO61 = 3;

GpioCtrlRegs.GPBQSEL2.bit.GPIO58 = 3; // Asynch
GpioCtrlRegs.GPBQSEL2.bit.GPIO59 = 3; // Asynch
GpioCtrlRegs.GPBQSEL2.bit.GPIO60 = 3; // Asynch
GpioCtrlRegs.GPBQSEL2.bit.GPIO61 = 3; // Asynch

Regards,
Manoj

C2000™︎ microcontrollers

C2000 microcontrollers forum

CCS/LAUNCHXL-F28379D: Transmitting SPI Data from one Launchpad to another