SDRPlayV3 API doesn't support multiple devices

[ijessen-mitll]

SDRPlayV3 API doesn't seem to support multiple devices within a single application.

While not strictly documented, this seems to be inherent in the API - I've written a small test application which confirms that once a device is selected, no further devices can be successfully selected by the same application.

#include "sdrplay_api.h"
#include <stdio.h>

int main()
{

    sdrplay_api_DeviceT devs[4];
    unsigned int ndev;
    int i;
    sdrplay_api_ErrT err;
    sdrplay_api_DeviceParamsT *deviceParams = NULL;
    sdrplay_api_DeviceT *chosenDevice = NULL;

    if ((err = sdrplay_api_Open()) != sdrplay_api_Success)
    {
        printf("sdrplay_api_Open failed %s\n", sdrplay_api_GetErrorString(err));
    }
    else
    {
        if ((err = sdrplay_api_DebugEnable(NULL, sdrplay_api_DbgLvl_Verbose)) != sdrplay_api_Success)
        {
            printf("sdrplay_api_DebugEnable failed %s\n", sdrplay_api_GetErrorString(err));
        }

        sdrplay_api_LockDeviceApi();
        // Fetch list of available devices
        if ((err = sdrplay_api_GetDevices(devs, &ndev, sizeof(devs) / sizeof(sdrplay_api_DeviceT))) != sdrplay_api_Success)
        {
            printf("sdrplay_api_GetDevices failed %s\n", sdrplay_api_GetErrorString(err));
            goto UnlockDeviceAndCloseApi;
        }
        printf("number of devices found: %d\n", ndev);

        for (int i = 0; i < ndev; ++i)
        {
            chosenDevice = &devs[i];

            // Select chosen device
            if ((err = sdrplay_api_SelectDevice(chosenDevice)) != sdrplay_api_Success)
            {
                printf("sdrplay_api_SelectDevice %d failed %s: %s\n", i+1, sdrplay_api_GetErrorString(err), sdrplay_api_GetLastError(chosenDevice)->message);
                goto UnlockDeviceAndCloseApi;
            }
        }
    }

UnlockDeviceAndCloseApi:
    // Unlock API
    sdrplay_api_UnlockDeviceApi();
CloseApi:
    // Close API
    sdrplay_api_Close();

    return 0;
}

The sdrangel plugin is written to allow multiple instances connected to multiple devices. However, any instance besides the first to be started will fail.

My suggestion is that sdrangel not enumerate any additional SDRPlay devices once the first has been selected (or at least make them unselectable).

[srcejon]

Do you know if SDRconnect supports multiple devices?

[ijessen-mitll]

The SDRconnect interface locks out the device selection dropdown once an RSP1b has been selected - so no, it doesn't seem to support multiple simultaneous devices (other than the dual tuners of an RSPduo, of course).

[MichSouth]

I have a RSPduo but I cannot select a second RSPduo to use the second tuner?

[srcejon]

SDRangel only supports one of RSPduo's tuners at a time, currently.