CC2500 Will not go to sleep

Hi.

Don't have a good explanation here. As you say, issuing a SIDLE will remove the possibility of WOR occuring. I assume you have read the datasheet which states that SPWD will first be executed when CSn goes high? What is the status byte returned when issuing the SPWD command?The 4 msb should be 0s.

You write “then try to communicating with it”

If this implies pulling CSn low, the Circuit naturally reenter active mode.

If you are testing in SmartRF studio you also need to turn of SPI polling

Settings>Polling Interval>Never

Monitoring current consumption is the only method to observe if the transceiver enter WOR or sleep mode. Any other activity will activate it, causing it to leave low power mode.

I am finding a similar problem with the CC2500.

I have a loop that you can see in the code below.

I am monitoring the current drawn by the board. If I issue an SPWD strobe shortly after power-up, in the beginning of the main() function, then the radio chip goes to sleep, and the total power consumption is extremely low.

But if I issue the SPWD strobe in the loop below, the board continues to draw 26 mA continuously.  It does not reduce in current for the 4 seconds that it is waiting between transmits.

I am using the EZ430-RF2500 board for this. Do you have any ideas?  Thanks.

Sage

   while(1)

  {

    // acquire sensor data

    sensorsAllAcq(&SensorData);

    // flush transmit buffer

    halRfStrobe( CC2500_SFTX );       

    // Turn on Tx mode

    halRfStrobe( CC2500_STX );

    // Pack the data into the payload packet

    PackPayload (&Payload, &SensorData);

    for (i=0; i<20000; i++){i=i+1;}

    // Transmit the data

    halRfWriteFifo( (uint8*) &Payload, sizeof(struct_Payload) );

    for (i=0; i<5000; i++){i=i+1;}

    // Power down the radio chip

    halRfStrobe(CC2500_SIDLE); // switch to IDLE state first

    for (i=0; i<100; i++){i=i+1;}

    halRfStrobe(CC2500_SPWD);

    // delay 'n' times 4 seconds until next sense event

    for (i = 0; i<n; i++)

    {

      __bis_SR_register(LPM3_bits + GIE);     // Enter LPM3, enable interrupts

      BLINK_RED(3000);

    } // delay loop

  } // while

I had similar problem and spent pretty lot time on it. In case if someone would use search and find this topic here is the solution for my case. First of all as it was written, it is necessary to set and keep high level for CE after SPWD to  have readio in sleep mode. But I also had to set some delays (after receiving status via SPI that shows that the data was received by radio. I have not measured acurately what their value should be, I simply set very big ones as it is ok for my case) between sending SIDLE and SPWD strobes and between SPWD and switching CE to high. Suppose the accurate values for this delays could be found somewhere in datasheet.

Could you tell me how can I measure the current so as to verify that my radio is/is not in idle or sleep state?

Moreover, lets make sure that i've understood the actions to be taken in order to get in Sleep Mode:

1) give SIDLE  command strobe

2)wait a bit

3)give SPWD command strobe

4)wait a bit

5) set CSn high 

Is that all? Are we done?

**What about that polling thing from the smartRF studio? Is there another register that

I should make sure that its  value doesn't provoke polling?

I would be grateful if I got some answers here.

Thanks a lot ! 

Thanks Dragker.

Your post was realy helpful.