MicroPhase
limited sample rate when using gnuradio with Pluto and Fmcomss firmwares.
When using gnuradio, the sample rate cannot be set above 5MSPS, otherwise the waveform is not right.
corresponding diagram:
When the sample rate is lowered to 5M, no problem.
I've narrowed it down to a potential problem with the iiod.
When using sample rate greater than 5M, the cpu usage of iiod is over 100%, that might be causing the problem.
Is there a solution to that?
With the pluto SDR, the CPU usage tops at about 60%, with rates around 5MSPS too.
Hello, While using the plutosdr firmware, the enternet is acting more like a usb ethernet.
Hello, While using the plutosdr firmware, the enternet is acting more like a usb ethernet.
Well, not only the plutosdr firmware, but also the FMCOMSS firmware. They are all limited to a rather low sample rate.
we will try to use fmcomms-x image for a test, for the plutosdr firmware maybe you can try to set the maximum cpu core number.
we will try to use fmcomms-x image for a test, for the plutosdr firmware maybe you can try to set the maximum cpu core number.
How to set maximum cpu core number? In /etc/security/limits.conf ?
I found that if you just using rx module in the gnuradio with fmcomms-x firmware, the sample rate could go up to 10MHz, while using both rx and tx module, the problem you mentioned above will occur.
However, there is a options for tx module could set to solve this issue, you can enable the "Cyclic" option for better performance.
I found that if you just using rx module in the gnuradio with fmcomms-x firmware, the sample rate could go up to 10MHz, while using both rx and tx module, the problem you mentioned above will occur.
However, there is a options for tx module could set to solve this issue, you can enable the "Cyclic" option for better performance.
That's hardly a solution. The option Cyclic means that the transmitter will repeat the first frame over and over again. No subsequent data will be sent.
There is a bottleneck, but the bottleneck seems to be on the software side. The iiod can be optimized to reduce CPU usage.