Transmission in SoapyLMS7 never stops

[TheGribble]

At the moment there doesn't seem to be any way of stopping transmission in SoapySDR with a lime mini. To test it I'm using a slight variation of the SimpleSiggen.py file included in soapySDR\python\apps folder, attached below.

The listing here runs a simple carrier for 15 seconds and then stops loading the buffer and calls sdr.deactivateStream(tx_stream) and sdr.closeStream(tx_stream). The Lime however continues transmitting the carrier until EnableChannel(xxx, xxx, false) is called in the SoapyLMS7 destructor, another ten seconds later.

There doesn't seem to be any way of stopping the transmission short of destroying the entire SoapyLMS7 instance and creating it again.

########################################################################
## Simple signal generator for testing transmit
########################################################################
import vext.gatekeeper
vext.gatekeeper.allowed_modules.add("SoapySDR")
vext.gatekeeper.allowed_modules.add("_SoapySDR")
import SoapySDR
from SoapySDR import * #SOAPY_SDR_ constants
import numpy as np
from optparse import OptionParser
import time
import os
import math

def siggen_app(
    args,
    rate,
    ampl=0.7,
    freq=None,
    txBw=None,
    txChan=0,
    rxChan=0,
    txGain=None,
    txAnt=None,
    clockRate=None,
    waveFreq=None
):
    if waveFreq is None: waveFreq = 1 #rate/10

    sdr = SoapySDR.Device(args)
    #set clock rate first
    if clockRate is not None: sdr.setMasterClockRate(clockRate)

    #set sample rate
    sdr.setSampleRate(SOAPY_SDR_TX, txChan, rate)
    print("Actual Tx Rate %f Msps"%(sdr.getSampleRate(SOAPY_SDR_TX, txChan)/1e6))

    #set bandwidth
    if txBw is not None: sdr.setBandwidth(SOAPY_SDR_TX, txChan, txBw)

    #set antenna
    print("Set the antenna")
    if txAnt is not None: sdr.setAntenna(SOAPY_SDR_TX, txChan, txAnt)

    #set overall gain
    print("Set the gain")
    if txGain is not None: sdr.setGain(SOAPY_SDR_TX, txChan, txGain)

    #tune frontends
    print("Tune the frontend")
    if freq is not None: sdr.setFrequency(SOAPY_SDR_TX, txChan, freq)

    #tx loop
    #create tx stream
    print("Create Tx stream")
    txStream = sdr.setupStream(SOAPY_SDR_TX, "CF32", [txChan])
    print("Activate Tx Stream")
    sdr.activateStream(txStream)
    phaseAcc = 0
    phaseInc = 2*math.pi*waveFreq/rate
    streamMTU = sdr.getStreamMTU(txStream)
    sampsCh0 = np.array([ampl]*streamMTU, np.complex64)
    
    timeLastPrint = time.time()
    totalSamps = 0
    while True:
        phaseAccNext = phaseAcc + streamMTU*phaseInc
        sampsCh0 = ampl*np.exp(1j*np.linspace(phaseAcc, phaseAccNext, streamMTU)).astype(np.complex64)
        phaseAcc = phaseAccNext
        while phaseAcc > math.pi*2: phaseAcc -= math.pi*2

        sr = sdr.writeStream(txStream, [sampsCh0], sampsCh0.size, timeoutUs=1000000)
        if sr.ret != sampsCh0.size:
            raise Exception("Expected writeStream() to consume all samples! %d"%sr.ret)
        totalSamps += sr.ret

        if time.time() > timeLastPrint + 15.0:
            print("Python siggen rate: %f Msps"%(totalSamps/(time.time()-timeLastPrint)/1e6))
            totalSamps = 0
            timeLastPrint = time.time()
            break

    #cleanup streams
    print("Cleanup stream")
    sdr.deactivateStream(txStream)
    sdr.closeStream(txStream)
    time.sleep(10.0)
    print("Done!")

def main():
    parser = OptionParser()
    parser.add_option("--args", type="string", dest="args", help="device factor arguments", default="")
    parser.add_option("--rate", type="float", dest="rate", help="Tx and Rx sample rate", default=2e6)
    parser.add_option("--ampl", type="float", dest="ampl", help="Tx digital amplitude rate", default=1.0)
    parser.add_option("--txAnt", type="string", dest="txAnt", help="Optional Tx antenna", default="BAND2")
    parser.add_option("--txGain", type="float", dest="txGain", help="Optional Tx gain (dB)", default=52)
    parser.add_option("--txChan", type="int", dest="txChan", help="Transmitter channel (def=0)", default=0)
    parser.add_option("--freq", type="float", dest="freq", help="Optional Tx and Rx freq (Hz)", default=900e6)
    parser.add_option("--txBw", type="float", dest="txBw", help="Optional Tx filter bw (Hz)", default=None)
    parser.add_option("--waveFreq", type="float", dest="waveFreq", help="Baseband waveform freq (Hz)", default=5e3)
    parser.add_option("--clockRate", type="float", dest="clockRate", help="Optional clock rate (Hz)", default=None)
    (options, args) = parser.parse_args()
    siggen_app(
        args=options.args,
        rate=options.rate,
        ampl=options.ampl,
        freq=options.freq,
        txBw=options.txBw,
        txAnt=options.txAnt,
        txGain=options.txGain,
        txChan=options.txChan,
        clockRate=options.clockRate,
        waveFreq=options.waveFreq,
    )

if __name__ == '__main__': main()

[9600]

For added context also:

https://discourse.myriadrf.org/t/an-error-in-the-limesuite-libraries/5774/2

[gracid]

You don't really need to setup/start streaming to see the LO, setFrequency() call is enough. The biggest problem is that other functions(calibration being one) depend on it being present. I'll need to look into what else it might break, for now, you can disable specific channels transmission with writeSetting(SOAPY_SDR_TX, 0, "PD_TLOBUF_TRF", "1").

[gracid]

Duplicate of #298