Hi, I get my first experiences with nRF905 modules (module DAYCOM M-FM-NR905 including spring antenna from Pollin) connected to ARDUINO DUEs. SPI communication works fine, I can readout the earlier programmed values into configuration register, TX-Address and TX-Payload from my ARDUINO board. My problem is that the receiver module doesn't recognize the carrier from the sender and therefore cannot receive any payload from the sender.
In my tests I configured the default values (exceptions: TX-, RX-addresss = 0xE7E700E7, PA_PWR is +10dBm, RX_PW and TX_PW are 28 on both modules). The antennas have a distance of a few cm.
The receiver function from both modules seems to work fine. Without any active nRF905 sender I receive sporadic messages when I reduce RX-AFW to 2 and deactivate checksum enable (AM and DR received). After activation of CRC no messages are indicated. (CD is activated sporadic but very rare).
After provision of TX-payload (28 bytes) and activation of ShockBurst TX at sender DR bit is deactivated after activation of TRX_CE and activated after less than 8,32msec again which corresponds to the nRF905 documentation V1.5. Unfortenately the receiving module (TRX_CE is steady activated, TX_EN is steady deactivated) doesn't activate CD signal in any case. At sender TX_EN is set steady active and and TRX_CE is activated for about 15msec after sending and verification of TX payload. Even when TRX_CE is steady active the receiver module does not indicate the carrier (same channel numbers 108 at 433MHz).
I also replaced my sender module but without any success.
I verified on HW level all connections from ARDUINO board over the pollin board until the corresponding pins on the nRF905 chip by multimeter and any short circuits between the pins on the pollin board plug but I have no possibility for measurements on air.
OS on ARDUINO DUE board is proprietary realtime OS (self developed), development system is AtmelStudio V7.
Thank you for your support.
