REB215(AT86RF215 version 3) RSSI is lower then it must be
Hello everyone. Sorry for my bad english, I hope you will understand me :)
I have two REB215-XPRO(without extension boards) with AT86RF215 (version 3) chips on them. Im using STM32 like controller with SPI protocol. I made the program for set one of REB215 like transmitter and the other one - receiver. I would like to measure the packet loss during translation. Two boards are on my table, its like 5 centimeters between them.
Well, so now you know how its looks like. And the problem is: Im trying to see the RSSI level on receiver. When i use spectroanalizer, its show me channel power level like +7dBm. But when i read the RSSI register from receiver, its show me around -50 dBm or smthing near that value. AGC level is maximum. I tried to change roles like transmitter and receiver between the boards, tried to change the distance between them, also tried to change the modulation FSK/OFDM/QPSK, all of these operations are dont make any sense. The RSSI level really lower than it must be.
P.S. I tried to use ideal generator. When i set 0 dBm on generator, i can see only -30 dBm on receiver.
P.P.S. All measurement are made with antennas. But i used to wires with attenuators too.
P.P.P.S. AGC target level doesnt make sense too.
Why could be the RSSI not correct?
Here are my registers parameters(the order of them is the same like in my code, if its make any matter):
RF09_CMD: 0x2 - Transmitter off;
RF09_CCF0H: 0x02, RF09_CCF0L: 0xC4, RF09_CNL: 0xEC, RF09_CNM: 0x80 - Frequency 790MHz, Channel mode 2.
BBC0_PC: 0x55 - MR-FSK
BBC0_FSKC1: 0x04 - Symbol Rate 300kHz
BBC0_FSKC0: 0xD2 - Banwidth Time Product 2.0, modulation index 0.5
RF09_TXDFE: 0x01 - Fcut = 0.25*Fs/2, Sample Rate Fs=4000kHz
RF09_RXBWC: 0x15 - Intermediate Frequency shift enable, Bandwidth frequency Fbw = 500kHz, Fif = 500kHz
RF09_RXDFE: 0x02 - Fcut = 0.25*Fs/2, Sample Rate Fs = 2000kHz
RF09_PAC: 0x7F - maximum power for transmition
RF09_CMD: 0x3 - Transmitter preparation