I can detect my LimeSDR Mini using LimeUtil.exe --find. I am able to connect, initialize, and configure frequency, gain, etc. — the LimeSDR Mini indicators blink as expected.
However, I cannot receive IQ samples. Does anyone know why this might be happening or how to fix it? Any advice would be greatly appreciated.
WinForm
int r = LimeAPI.LMS_Open(out dev, null, IntPtr.Zero);
if (r != 0)
{
MessageBox.Show(“Unable to open the device！”);
return;
}
r = LimeAPI.LMS_Init(dev);
if (r != 0)
{
MessageBox.Show(“Init error！”);
LimeAPI.LMS_Close(dev);
return;
}
Thread.Sleep(200);
r = LimeAPI.LMS_EnableChannel(dev, 0 /RX/, 0, 1 /enable/);
if (r != 0) MessageBox.Show("EnableChannel failed: " + r);
Thread.Sleep(200);
LimeAPI.LMS_SetLOFrequency(dev, false, 0, 433.907e6);
Thread.Sleep(200);
double freq;
LimeAPI.LMS_GetLOFrequency(dev, false, 0, out freq);
MessageBox.Show("LO freq = " + freq);
// 設 SPAN = SampleRate
LimeAPI.LMS_SetSampleRate(dev, 2e6, 0);
Thread.Sleep(200);
LimeAPI.LMS_SetAntenna(dev, 0, 0, “LNA_H”);
Thread.Sleep(200);
LimeAPI.LMS_SetGaindB(dev, 0, 0, 30.0); // RX 通道 0, 30dB
Thread.Sleep(200);
LimeAPI.LMS_SetTestSignal(dev, 0, 0, 0, 0, 0);
Thread.Sleep(200);
// 6. 設定 Stream
LimeAPI.lms_stream_t rx = new LimeAPI.lms_stream_t()
{
isTx = 0,
channel = 0,
fifoSize = 1024 * 1024,
throughputVsLatency = 0.5f,
dataFmt = 0,
handle = IntPtr.Zero
};
IntPtr streamPtr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(LimeAPI.lms_stream_t)));
Marshal.StructureToPtr(rx, streamPtr, false);
LimeAPI.LMS_SetupStream(dev, streamPtr);
Thread.Sleep(200);
LimeAPI.LMS_StartStream(streamPtr);
Thread.Sleep(200);
// 7. 讀取一次 IQ
int SAMPLE_COUNT = 4096;
short buffer = new short[SAMPLE_COUNT * 2];
GCHandle handle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
LimeAPI.lms_stream_meta_t meta = new LimeAPI.lms_stream_meta_t();
var sw = System.Diagnostics.Stopwatch.StartNew();
while (sw.Elapsed.TotalSeconds < 5)
{
int rec = LimeAPI.LMS_RecvStream(streamPtr, handle.AddrOfPinnedObject(), (uint)SAMPLE_COUNT, ref meta, 1000);
if (rec > 0)
{
Console.WriteLine($“Received {rec} samples”);
for (int i = 0; i < Math.Min(10, rec * 2); i += 2)
Console.WriteLine($“I:{buffer[i]} Q:{buffer[i + 1]}”);
}
}
handle.Free();
// 8. Stop & cleanup
LimeAPI.LMS_StopStream(streamPtr);
Thread.Sleep(200);
LimeAPI.LMS_DestroyStream(dev, streamPtr);
Thread.Sleep(200);
Marshal.FreeHGlobal(streamPtr);
LimeAPI.LMS_Close(dev);
Thread.Sleep(200);
LimeAPI.cs:
const string dll = “LimeSuite.dll”; // 在 bin 資料夾要有這個檔
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_Open(out IntPtr device, string info, IntPtr args);
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_Close(IntPtr device);
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_Init(IntPtr device);
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_SetLOFrequency(
IntPtr device,
bool dir_tx, // false = RX / true = TX
uint channel,
double frequency
);
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_GetLOFrequency(
IntPtr device,
bool dir_tx,
uint channel,
out double frequency
);
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern double LMS_GetRSSI(IntPtr device, uint channel);
[DllImport(“LimeSuite.dll”, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_EnableChannel(
IntPtr device,
int dir_tx, // 0=RX, 1=TX
uint channel,
int enabled // 0=disable, 1=enable
);
[DllImport(dll, CallingConvention = CallingConvention.Cdecl, EntryPoint = “LMS_SetSampleRate”)]
public static extern int LMS_SetSampleRate(
IntPtr device,
double rate, // sample rate (Hz)，例如 2e6 = 2 MHz
uint oversample // 通常填 0 (driver 決定)，或 1,2,… 視需求
);
// 設定增益（RX / TX）
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_SetGaindB(IntPtr device, int isTx, uint channel, double gain);
// Stream 結構
[StructLayout(LayoutKind.Sequential)]
public struct lms_stream_t
{
public int isTx;
public uint channel;
public uint fifoSize;
public float throughputVsLatency;
public int dataFmt; // 0=I16, 1=F32
public IntPtr handle;
}
[StructLayout(LayoutKind.Sequential)]
public struct lms_stream_meta_t
{
public int waitForTimestamp;
public ulong timestamp;
}
// Stream 操作
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_SetupStream(IntPtr device, IntPtr stream);
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_StartStream(IntPtr stream);
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_RecvStream(IntPtr stream, IntPtr samples, uint sample_count, ref lms_stream_meta_t meta, uint timeout_ms);
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_StopStream(IntPtr stream);
[DllImport(dll, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_DestroyStream(IntPtr device, IntPtr stream);
[DllImport(“LimeSuite.dll”, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_SetAntenna(IntPtr device, int dir_tx, uint channel, string name);
[DllImport(“LimeSuite.dll”, CallingConvention = CallingConvention.Cdecl)]
public static extern int LMS_SetTestSignal(
IntPtr device, // device handle
int dir, // 0 = RX, 1 = TX
uint channel,
int type, // LMS_TESTSIG_NONE, LMS_TESTSIG_NCODIV8, …
double freq,
double amplitude
);
