LimeSDR / LimeSDR mini USB 2.0 backwards compatibility

[sqrt2]

Hello, I am planning to buy a LimeSDR, but I am not quite sure how well it is going to work on my old laptop:

• only USB 2.0 ports
• Intel Core i5 CPU (integrated Intel HD Graphics) with OpenCL 2.0 support

I read that the bandwidth of USB 2.0 is compared to USB 3.0 significantly smaller, limiting the transmission of samples. Does anyone have experience with a LimeSDR connected to an USB 2.0 port? What performance is to be expected?

[M0GLO]

5MHz - 10MHz bandwidth is what I found on my old system with USB2, it would be unreliable much higher than that.

[yindra]

different version of limesuite install different version of firmware. I found that firmware version 18.06 is not able to communicate over USB 2.0, except to perform self-test.

LimeSDR-USB Transmit with gr-limesdr

Here is the Quick Test result: [image] Here is the RX test signal: [image] Here is the TX carrier signal: [20180620_txCarrierSignal] Here is the TX test signal: [20180620_txTestSignal] I got the same results when I loaded the 18.06 firmware with Modules->Programming (it then downloaded the 18.06 firmware and installed it) with LimeSuiteGUI_20180613_1cb1723.exe

I found that the limesdr_toolbox software can fill the transmit fifo, but the LimeSDR-USB never reads data from the transmit fifo. The limesdr_toolbox software gets stuck once the lime::StreamChannel’s fifo is full.

[sqrt2]

I just tested mine on ubuntu 18.04 and it performs just as well as you state. Thank you!