MSP432P4111: [MSP432 Bluetooth plugin] How to increase communication throughput between a host MCU (SAP) and a simple network processor (CC2640R2)

Hi, 

Nhat Pham said:

but a header file for is missing (npi_tl_spi.h)

C:\ti\simplelink_cc2640r2_sdk_2_30_00_28\source\ti\blestack\npi\src\inc
C:\ti\simplelink_cc2640r2_sdk_2_30_00_28\source\ti\blestack\npi\src\unified\inc
C:\ti\simplelink_cc2640r2_sdk_2_30_00_28\source\ti\ble5stack\npi\src\inc

Hi Nhat,

Nhat Pham said:

Btw, how do you think about the UART baud rate? I still have no clue why it can be increased to 460800.

Some MSPs, some silicon releases have issues with 1-2 Mbps UART speeds. 
Having no experience with MSP432P4111, I recommend you to create a separate thread asking for the best experience on UART speeds with MSP-EXP432P4111, DMA settings, etc.

I would confirm the power level of the MSP432.

 *  The Power driver currently supports four pre-defined performance levels:
 *  @code
 *    Level    MCLK (MHz)    HSMCLK (MHz)    SMCLK (MHz)    ACLK (Hz)
 *    -----    ----------    ------------    -----------    ---------
 *      0         12              3              3           32768
 *      1         24              6              6           32768
 *      2         48             24             12           32768
 *      3         48             48             24           32768

Table 24-5 in the TRM shows the error associated for a given BRCLK (SMCLK) and desired baud rate.

Regards,

Chris 

Hi Tom and Chris,

I'm not sure that I got it right but it seems to me that the issue of UART baud rate is inside the MSP432 BLE plugin (i.e. the simple application processor (SAP) library). When I tried to use the same UART on MSP432, without attaching it to the SAP library, to send out some dummy data at 460800, I can see it sends out data properly through a logic analyzer. Thus, I'm wondering whether we have any limitation for UART baud rate in the SAP library or not?

P.s: About the use of SPI for the MSP432 BLE plugin, I found out in the user's guide that it only supports UART. "The SAP layer supports a physical UART Network Processor Interface (NPI) layer between the SimpleLink host MCU and the CC26xx. ". So I think I will skip SPI and stick with UART for now.

Cheers,

Nhat.

Hi Chris,

I'm looking into the clock now and I'll let you know if I found anything. One interesting thing I have tried is to use the same UART to transmit data out at 460800 baud instead of assigning to the BLE SAP library, and it does transmit. But the BLE SAP doesn't work with the same UART at that baud rate and above (it does work with 230400, though.). The code I use is from the simple_application_processor example in MSP432 BLE plugin

// The code is working. UART can transmit data out.

char input[3] = {0x01, 0x02, 0x03};
UART_Handle uart;
UART_Params uartParams;

// Create a UART with data processing off.
UART_Params_init(&uartParams);
uartParams.writeDataMode = UART_DATA_BINARY;
uartParams.readDataMode = UART_DATA_BINARY;
uartParams.readReturnMode = UART_RETURN_FULL;
uartParams.readEcho = UART_ECHO_OFF;
uartParams.baudRate = 460800;
// Open an instance of the UART drivers
uart = UART_open(Board_UART1, &uartParams);

UART_write(uart, &input, 3);

// The SAP library is not working when sapParams.port.remote.bitRate is increased to 460800

/* Initialize UART port parameters within SAP parameters */
if (SAP_initParams(SAP_PORT_REMOTE_UART, &sapParams) != SNP_SUCCESS) {
Display_print0(displayOut, 0, 0,
(char* ) "SAP_initParams: SNP_INVALID_PARAMS");
}

sapParams.port.remote.mrdyPinID = Board_MRDY;
sapParams.port.remote.srdyPinID = Board_SRDY;
sapParams.port.remote.boardID = Board_UART1;
sapParams.port.remote.bitRate = 460800;

/* Setup NP module */
if (SAP_open(&sapParams) != SNP_SUCCESS) {
Display_print0(displayOut, 0, 0, (char* ) "SAP_open: SNP_FAILURE");
}

Have you looked at the NPITask_Params_init()?  I am not very familiar with this but stumbled across this wiki:

Chris

Please update the board file () to add UART details for 460800 baudrate if you intend to support that as well. This structure should have details for all baudrates that may be supported by the application

Hi Kasthuri,

I already setup the UART baudate table. My display library is running with UART baudrate 921600.

Cheers,

NP.

Hi Kristen,

It's the sample_application_processor [1] example provided inside SIMPLELINK-SDK-BLUETOOTH-PLUGIN_1.40.00.42 [2]. The hardware setup is the same as the example where MSP432P4111LP is used with CC2640R2LP

I only make 2 small changes:

1. In the sample_application_processor for MSP432, increase UART baud rate when initializing SAP library.

case AP_RESET: {
      /* Make sure CC26xx is not in BSL */
      GPIO_write(Board_RESET, Board_LED_OFF);
      GPIO_write(Board_MRDY, Board_LED_ON);

      usleep(10000);

      GPIO_write(Board_RESET, Board_LED_ON);

      /* Initialize UART port parameters within SAP parameters */
      if (SAP_initParams(SAP_PORT_REMOTE_UART, &sapParams) != SNP_SUCCESS) {
        Display_print0(displayOut, 0, 0,
            (char* ) "SAP_initParams: SNP_INVALID_PARAMS");
      }

      sapParams.port.remote.mrdyPinID = Board_MRDY;
      sapParams.port.remote.srdyPinID = Board_SRDY;
      sapParams.port.remote.boardID = Board_UART1;
      sapParams.port.remote.bitRate = 460800;

      /* Setup NP module */
      if (SAP_open(&sapParams) != SNP_SUCCESS) {
        Display_print0(displayOut, 0, 0, (char* ) "SAP_open: SNP_FAILURE");
      }

      /* Register Application thread's callback to receive
       asynchronous requests from the NP. */
      SAP_setAsyncCB(AP_asyncCB);

2. Change the UART baud rate in the simple_np_cc2640r2lp_app on the CC2640R2 side to accept the new baud rate.

uint8_t NPITask_Params_init(uint8_t portType, NPI_Params *params)
{
  if (params != NULL)
  {
    *params = NPI_defaultParams;

#if defined(NPI_USE_UART)
    UART_Params_init(&params->portParams.uartParams);
    params->portParams.uartParams.readDataMode = UART_DATA_BINARY;
    params->portParams.uartParams.writeDataMode = UART_DATA_BINARY;
    params->portParams.uartParams.readMode = UART_MODE_CALLBACK;
    params->portParams.uartParams.writeMode = UART_MODE_CALLBACK;
    params->portParams.uartParams.readEcho = UART_ECHO_OFF;
    params->portParams.uartParams.baudRate = 460800;
#elif defined(NPI_USE_SPI)
    SPI_Params_init(&params->portParams.spiParams);
    params->portParams.spiParams.mode = SPI_SLAVE;
    params->portParams.spiParams.bitRate = 8000000;
    params->portParams.spiParams.frameFormat = SPI_POL1_PHA1;
#endif //NPI_USE_UART

    return NPI_SUCCESS;
  }

  return NPI_TASK_INVALID_PARAMS;
}

I don't think we have any problem on CC2640R2 side because if you take a look at the logic analyzer capture in my first post, CC2640R2 can send out Power-up indicator message with baud rate at 460800, only MSP432 doesn't respond.

Btw, I can zip the current projects and send them to you, but since I have changed a lot in the code to fit with my customized hardware, it won't work directly with the Launchpads anymore.

[1]  

[2]  

I'm still stuck with this and I currently fall back to use a Bluetooth SPP module (i.e. RN-42). Still, it's only temporary, though.