sl_Send flags: power CC3200

Hi Fernando,

Sorry, but no, we can't transmit in maximum power of -3 ,1dB.

Please note that the lowest power level is 15.
In addition the power is dependent on the transmitted rate (higher rate can transmit in lower power), but even in the highest rate we will transmit at about 3dBm.

Thanks,
Alon

Hi,

I did not explain myself properly. What I really want is to set the transmit power to:

Maximum-power

-(minus)

3,1dB

Please confirm me if the following command

Status= sl_Send(socket_descriptor,RawData,sizeof(RawData),SL_RAW_RF_TX_PARAMS(iChannel, rate, iTxPowerLevel, PREAMBLE));

with 

iTxPowerLevel = 1

transmits at maximum-power -(minus)3,0dB.

Thanks!

Hi Fernando,

OK, sorry for missing your point.

The answer is yes.

Power level 1, will reduce the power in 0,3 dBm.

Thanks,
Alon

Hi Alon, 

I guess it´s just a typo, but I need to be sure and it makes a huge difference in dBm:

1) Power level 1, will reduce the power in 0,3 dBm. (If this is true power level 3, would reduce power in 0.9dB, rigth?)

or

2) Power level 1, will reduce the power in 3 dBm.

?

I guess the correct statement is the second one, right?

Hi Fernando,

The answer is somewhere in the middle. power levels don't translate directly to exact amount of dBm.
There is a power curve per wifi rate (there are different modulations used and also each rate is effected a bit differently).
The answer I gave you, meant that power level 1 will reduce the output power somewhere between 0 to 3 dBm depending on the rate of the transmitted packet.

Thanks,
Alon

Hello Fernando,

The section " 4.8  Current Consumption" in the CC3200 datasheet shows you the typical plots on the TX output power variation with different TX power level settings. There are plots for different modulation rates there. I hope those plots help you understand the output power you can expect with different power settings in a typical case.

 

Regards,

Dham

Hi Alon and Dham,

Thanks for the info!

I am working in the Stack Bypass Mode, and using the following command

Status= sl_Send(socket_descriptor,RawData,sizeof(RawData),SL_RAW_RF_TX_PARAMS(iChannel, rate, iTxPowerLevel, PREAMBLE));

with

int rate = 13; //13: 54Mbps

However the packets are sent with different rates, according to the wireshark capture.

Since the transmission occurs at different rates, I would like to see all the plots of the "Tx Power" as a functions of the "Tx power level setting", for all transmission rates. I mean, plots like the ones in the section " 4.8 Current Consumption" in the CC3200 datasheet, but for all data rates. Does this exist? My goal is to choose a power level setting that on average reduces the Tx power in 3dB from the maximum_Tx_power, averaging over all power rates. According to the figures in the CC3200 datasheet, it seems that this value is 3, right?

Thanks!

Hello Dham,
I need to reduce the Tx power by 3dB to compensate for an antenna gain at the receiver.
Thanks for the information, I´ll verify the answer to close the thread.
Regards,
Fernando