Need assistance with loopback modes
Posted: Sat Sep 13, 2014 2:00 am
Hi,
I am having some trouble testing my transmitter using the internal loopback. My device configuration does work, I've tested it by running bladeRF-cli after my program has executed and the loopback mode correlates, and just to confirm I have tested all of the loopback modes available.
The tx / rx procedure works as follows:
I'm using a script in MATLAB to plot both real and imaginary parts of the transmitted and received waveforms. The transmitted one looks like it should (linear FM), but the received signal seems to be noise only.
For interest's sake my source code is available at https://github.com/git-strider/bladerf-radar, the TX/RX procedures are written in txrx.c.
So here are my questions:
Jaco.
I am having some trouble testing my transmitter using the internal loopback. My device configuration does work, I've tested it by running bladeRF-cli after my program has executed and the loopback mode correlates, and just to confirm I have tested all of the loopback modes available.
The tx / rx procedure works as follows:
- Configure TX / RX data streams
Fill a TX buffer with the waveform .bin file
Enable the RX module
Enable the TX module
Transmit the samples in the TX buffer
Disable the TX module
Receive samples until a flag is set (when the rx.bin file is done writing)
Disable the RX module
I'm using a script in MATLAB to plot both real and imaginary parts of the transmitted and received waveforms. The transmitted one looks like it should (linear FM), but the received signal seems to be noise only.
For interest's sake my source code is available at https://github.com/git-strider/bladerf-radar, the TX/RX procedures are written in txrx.c.
So here are my questions:
- My files are simply a list of IQ pairs, e.g. I1 Q1 I2 Q2 etc., is this correct?
Is the loopback mode even an appropriate method to test my transmit / receive routines?
Is the synchronous interface sufficient for what I'm trying to do?
Jaco.