CC2651P3: FCC/CE radio testing support

Hi Ryan,

I am testing rfDiagnostics on my LP-CC2651P3. On the board, I removed C16 and placed a 15pF cap at C15 to use the U.FL connector. I loaded the rfDiagnostics project (did not make any config or code changes). I entered the following commands to enable CW at 2.425GHz:

AT+I 1
ATPFR=2425000000
ATPTM=0

I also read the power level setting:

ATPPW?
5 dBm
OK

However, when I measure the output power I get +1.1dBm (3.9dBm too low). Any ideas?

Thanks,
Andy

You've gathered a basic understanding of AT commands.  You do not have to initialize ATPTM to zero, you can set to one for Carrier Wave mode followed by zero to reset.  Since you are using a LaunchPad, how does this same setup perform in Smart RF Studio?  Why did you choose a capacitor value of 15 pF and what are the results when evaluating High PA mode (enabled in the SysConfig -> Custom -> IEEE module)?

Regards,
Ryan

Hi Ryan,

I tried Smart RF Studio and got the same results. Then I changed my RF cabling and now the measured power level is only 0.8dB below the setting. So that is good news that is was a cable issue.

FYI the 15pF capacitor value came from the comment in the schematic:

Glad to hear the results have improved

Regards,
Ryan

Hi Ryan,

I'm now trying to build rfDiagnostics for our custom board. I used "switch device", which then allowed me to change the antenna switching GPIO configuration in the RF driver section. Now when I build I get the error "you_must_implement_rfDriverCallbackAntennaSwitching_see_generated_ti_drivers_config_c_in_debug_folder_or_sysconfig_preview ./syscfg/ti_drivers_config.o"

which points me to the following code:

void __attribute__((weak)) rfDriverCallbackAntennaSwitching(RF_Handle client, RF_GlobalEvent events, void *arg)
{
/* ======== PLEASE READ THIS ========
*
* This function is declared weak for the application to override it,
* and the undefined function call below is intended to catch the
* developer's attention at link time.
* A new definition of 'rfDriverCallbackAntennaSwitching' is required.
*
* Please copy this function definition to create your own, but make
* sure to remove '__attribute__((weak))' for your definition and
* remove the below function declaration and function call.
*
* To handle the events listed in '.globalEventMask', please see the
* help text provided in 'rfDriverCallback' above.
*
* For an example on how to interact with the selected antenna pins,
* please see the code snippet below:
*
* --- Code snippet begin ---
*
* // > This assumes antenna switch pins have been added to GPIO via
* // > sysconfig with the following properties:
* // > mode: Output
* // > initialOutputState: Low
* // > outputStrength: High
*
* // > Set pin output value manually
* GPIO_write(CONFIG_RF_24GHZ, 0); // Low
* GPIO_write(CONFIG_RF_24GHZ, 1); // High
*
* // > Mux pin to be driven/controlled by the RF Core
* // > (RFC GPIO0 is here only used as an example)
* GPIO_setMux(CONFIG_RF_24GHZ, IOC_PORT_RFC_GPO0);
*
* // > Mux pin to be controlled manually (i.e. release RF Core control)
* GPIO_setMux(CONFIG_RF_24GHZ, IOC_PORT_GPIO);
*
* --- Code snippet end ---
*/
extern void you_must_implement_rfDriverCallbackAntennaSwitching_see_generated_ti_drivers_config_c_in_debug_folder_or_sysconfig_preview(void);
you_must_implement_rfDriverCallbackAntennaSwitching_see_generated_ti_drivers_config_c_in_debug_folder_or_sysconfig_preview();
}

Now I have some questions. Do I need to control the antenna GPIO in firmware using:

GPIO_write(CONFIG_RF_24GHZ, 0); // Low
GPIO_write(CONFIG_RF_24GHZ, 1); // High

or can I have it controlled by the RF core:

GPIO_setMux(CONFIG_RF_24GHZ, IOC_PORT_RFC_GPO0);

And, If I must control it in firmware I'm not sure how that is possible, since there is no RF_GlobalEvent for enabling/disabling the PA:

typedef enum {
RF_GlobalEventRadioSetup = (1 << 0), ///< The RF core is being reconfigured through a setup command.
RF_GlobalEventRadioPowerDown = (1 << 1), ///< The RF core is being powered down.
RF_GlobalEventInit = (1 << 2), ///< RF_open() is called for the first time (number of registered clients changes from 0 to 1).
RF_GlobalEventCmdStart = (1 << 3), ///< A command chain is being dispatched to the radio.
RF_GlobalEventCmdStop = (1 << 4), ///< Command termination event is handled.
RF_GlobalEventCoexControl = (1 << 5), ///< Change to coex configuration is requested
RF_GlobalEventTempNotifyFail = (1 << 6), ///< Registration of temperature notification was unsuccessful
} RF_GlobalEvent;

Thanks,
Andy

Hi Andy,

Since you are not using a LaunchPad design, you must include rfDriverCallbackAntennaSwitching inside your application.  The following code excerpt is copied from the default project ti_drivers_config.c:

#include <ti/drivers/rf/RF.h>
void __attribute__((weak)) rfDriverCallbackAntennaSwitching(RF_Handle client, RF_GlobalEvent events, void *arg)
{

    if (events & RF_GlobalEventRadioSetup) {
        /* Switch off all paths. */
        GPIO_write(CONFIG_RF_HIGH_PA, 0);
        GPIO_write(CONFIG_RF_24GHZ, 0);

        /* Decode the current PA configuration. */
        RF_TxPowerTable_PAType paType = (RF_TxPowerTable_PAType)RF_getTxPower(client).paType;

        if (paType == RF_TxPowerTable_HighPA) {
            /*
            * Mux GPIOs to RF Core signals:
            * - High PA    --> HIGH PA
            * - LNA enable --> 2.4 GHz
            */
            GPIO_setMux(CONFIG_RF_HIGH_PA, IOC_PORT_RFC_GPO3);
            GPIO_setMux(CONFIG_RF_24GHZ, IOC_PORT_RFC_GPO0);
        } else {
            /* RF Core active --> 2.4 GHz   */
            GPIO_write(CONFIG_RF_24GHZ, 1);
        }
    }
    else if (events & RF_GlobalEventRadioPowerDown) {
        /* Switch off all paths. */
        GPIO_write(CONFIG_RF_24GHZ, 0);
        GPIO_write(CONFIG_RF_HIGH_PA, 0);

        /* Reset the IO multiplexer to GPIO functionality */
        GPIO_setMux(CONFIG_RF_24GHZ, IOC_PORT_GPIO);
        GPIO_setMux(CONFIG_RF_HIGH_PA, IOC_PORT_GPIO);
    }
}

Inserting this at the bottom of rfDiagnostics.c should allow your code to build.  You should not have to control antenna GPIO outside of setting the correct configurations for each event inside this function.  Pin selection and GPIO configuration, including "Value Inversion", is available from the SysConfig -> RF module.  You can also review relevant E2E threads on this topic.

Regards,
Ryan