CC1200EMK-868-930: Problems receiving all of my sent data dependent on the packet length

Hi

I took the cc120x_easy_link example from and modified it as shown below:

#define ISR_ACTION_REQUIRED 1
#define ISR_IDLE            0

#define PKTLEN              6
#define GPIO3               0x04
#define GPIO2               0x08
#define GPIO0               0x80

static uint8  packetSemaphore;
static uint32 packetCounter, countValue = 0;

static void initMCU(void);
static void registerConfig(void);
static void runTX(void);
static void createPacket(uint8 randBuffer[]);
static void radioTxISR(void);
static void updateLcd(void);
static void waitUs(uint16 uSec);
static void waitMs(uint16 mSec);

void main(void) {

    uint8 writeByte;
    
    // Initialize MCU and peripherals
    initMCU();

    // Write radio registers
    registerConfig();
    
    writeByte = 0x00; // Fixed Packet Lenght
    cc120xSpiWriteReg(CC120X_PKT_CFG0, &writeByte, 1);
    
    writeByte = PKTLEN; // length = PKTLEN
    cc120xSpiWriteReg(CC120X_PKT_LEN, &writeByte, 1);

    // Enter runTX, never coming back
    runTX();
}

static void runTX(void) {
    // Initialize packet buffer of size PKTLEN + 1
    uint8 txBuffer[PKTLEN] = {0};

    // Connect ISR function to GPIO2
    ioPinIntRegister(IO_PIN_PORT_1, GPIO2, &radioTxISR);

    // Interrupt on falling edge
    ioPinIntTypeSet(IO_PIN_PORT_1, GPIO2, IO_PIN_FALLING_EDGE);

    // Clear ISR flag
    ioPinIntClear(IO_PIN_PORT_1, GPIO2);

    // Enable interrupt
    ioPinIntEnable(IO_PIN_PORT_1, GPIO2);

    // Update LCD
    updateLcd();

    // Infinite loop
    while(TRUE)
    {
        // Update packet counter
        packetCounter = 0;
        countValue = 0;
        
        while(!bspKeyPushed(BSP_KEY_ALL)); 
        
        while (packetCounter++ < (256/PKTLEN)) {
            for(uint8 i = 0; i < PKTLEN; i++) {
                txBuffer[i] = countValue++;
            }
            
            cc120xSpiWriteTxFifo(txBuffer, sizeof(txBuffer));

            trxSpiCmdStrobe(CC120X_STX);

            while(packetSemaphore != ISR_ACTION_REQUIRED);

            packetSemaphore = ISR_IDLE;
        
            updateLcd();
            waitMs(100);
        }
    }
}

static void radioTxISR(void) {

    // Set packet semaphore
    packetSemaphore = ISR_ACTION_REQUIRED;

    // Clear ISR flag
    ioPinIntClear(IO_PIN_PORT_1, GPIO2);
}

static void initMCU(void) {

    // Init clocks and I/O
    bspInit(BSP_SYS_CLK_8MHZ);

    // Init LEDs
    bspLedInit();

    // Init buttons
    bspKeyInit(BSP_KEY_MODE_POLL);

    // Initialize SPI interface to LCD (shared with SPI flash)
    bspIoSpiInit(BSP_FLASH_LCD_SPI, BSP_FLASH_LCD_SPI_SPD);

    // Init LCD
    lcdInit();

    // Instantiate transceiver RF SPI interface to SCLK ~ 4 MHz
    // Input parameter is clockDivider
    // SCLK frequency = SMCLK/clockDivider
    trxRfSpiInterfaceInit(2);

    // Enable global interrupt
    _BIS_SR(GIE);
}

static void registerConfig(void) {

    uint8 writeByte;

    // Reset radio
    trxSpiCmdStrobe(CC120X_SRES);

    // Write registers to radio
    for(uint16 i = 0;
        i < (sizeof(preferredSettings)/sizeof(registerSetting_t)); i++) {
        writeByte = preferredSettings[i].data;
        cc120xSpiWriteReg(preferredSettings[i].addr, &writeByte, 1);
    }
}

static void updateLcd(void) {

    // Update LDC buffer and send to screen.
    lcdBufferClear(0);
    lcdBufferPrintString(0, "EasyLink Test", 0, eLcdPage0);
    lcdBufferSetHLine(0, 0, LCD_COLS-1, 7);
    lcdBufferPrintString(0, "Sent packets:", 0, eLcdPage3);
    lcdBufferPrintInt(0, packetCounter, 70, eLcdPage4);
    lcdBufferPrintString(0, "Packet TX" , 0, eLcdPage7);
    lcdBufferSetHLine(0, 0, LCD_COLS-1, 55);
    lcdBufferInvertPage(0, 0, LCD_COLS, eLcdPage7);
    lcdSendBuffer(0);
}

#pragma optimize=none
static void waitUs(uint16 uSec) { // 5 cycles for calling

    // The least we can wait is 3 usec:
    // ~1 usec for call, 1 for first compare and 1 for return
    while(uSec > 3) {  // 2 cycles for compare
                       // 2 cycles for jump
        NOP();         // 1 cycle for nop
        NOP();         // 1 cycle for nop
        NOP();         // 1 cycle for nop
        NOP();         // 1 cycle for nop
        NOP();         // 1 cycle for nop
        NOP();         // 1 cycle for nop
        NOP();         // 1 cycle for nop
        NOP();         // 1 cycle for nop
        uSec -= 2;     // 1 cycle for optimized decrement
    }
}                      // 4 cycles for returning

#pragma optimize=none
static void waitMs(uint16 mSec) {
    while(mSec-- > 0) {
        waitUs(1000);
    }
}

I used SmartRF Studio in fixed packet length mode, and were able to receive all packets.

BR

Siri

link