Packet format debugging

When testing a custom packet format, it is often convenient to see what the CC13x0 sends on the air. The RF core provides the internal signal MCE_GPO0 which reflects the binary modulator input. Figure 30. shows a pin dump for a packet with the following configuration:

  • .preamConf.nPreamBytes = 1
  • .syncWord = 0x930B51DE
  • .pktConf.bVarLen = 0x0
  • payload: 4 bytes: { 0x81, 0x82, 0x83, 0x84}
../_images/mce_gpo0_output.png

Figure 30. Output of the internal modulator signal MCE_GPO0 dumped with a logic analyer.

The triggers represent the parts:

  1. Preamble
  2. Sync word
  3. Payload
  4. CRC
  5. End

There are signal fragments at the beginning of the packet which need to be filtered out. The following code snippet routes MCE_GPO0 to Board_LED1:

#include <inc/hw_rfc_dbell.h>

// Overrides for CMD_PROP_RADIO_DIV_SETUP
static uint32_t pOverrides[] =
{
    // Route MCE_GPO0 to RFC_GPO0
    HW_REG_OVERRIDE(0x1110, RFC_DBELL_SYSGPOCTL_GPOCTL0_MCEGPO0),
    // ...
}


#include <ti/drivers/pin/PINCC26XX.h>

// Route RFC_GPO0 to an LED
PINCC26XX_setMux(ledPinHandle, Board_LED1, PINCC26XX_MUX_RFC_GPO0);

More information on signal routing can be found here.