Implement auto-device selection and enhance

channel handling

Refactored code to improve usability and error handling by implementing
automatic device selection when no device is explicitly specified. New
functionalities include opening devices based on provided info, and a
more robust way to retrieve and validate the number of RX and TX
channels. These changes streamline the device and channel setup process,
especially for systems with a single connected device.

- Introduced `openDevice` to encapsulate device opening logic with
fallback to the first available device.
- Added `getDeviceChannels` and `getChannelsFromInfo` for retrieving
channel information.
- Ensured LimeConfig struct now includes a `device` field to store the
selected device.
- Modified experiment setup to automatically select a device if not
configured and validate channel availability.
- Updated HDF attribute population to include device information.

These improvements should reduce the likelihood of user errors and
simplify the configuration process when working with LimeSDR devices.

src/limedriver.cpp

@@ -114,6 +114,48 @@ std::vector<string> getDeviceList() {
   return deviceList;
 }
 
+lms_device_t *openDevice(const std::string &info) {
+  // Open the device with the given info string
+
+  string info_string = info;
+
+  if (info_string.empty()) {
+    std::vector<string> deviceList = getDeviceList();
+    if (deviceList.size() == 0) {
+      std::cout << "No devices found" << std::endl;
+      error();
+    }
+    
+    info_string = deviceList[0];
+  }
+
+  lms_device_t *dev = NULL;
+  if (LMS_Open(&dev, info.c_str(), NULL)) {
+    error();
+  }
+
+  return dev;
+}
+
+std::pair<int, int> getDeviceChannels(lms_device_t *dev) {
+  // Get the number of RX and TX channels of the device
+
+  lms_info_str_t list[10];
+  int rx = LMS_GetNumChannels(dev, LMS_CH_RX);
+  int tx = LMS_GetNumChannels(dev, LMS_CH_TX);
+
+  return std::make_pair(rx, tx);
+}
+
+std::pair<int, int> getChannelsFromInfo(const std::string &info) {
+  // Get the number of RX and TX channels from the device info string
+  lms_device_t *dev = openDevice(info);
+  std::pair<int, int> values = getDeviceChannels(dev);
+  LMS_Close(dev);
+  return values;
+}
+
+
 // Custom function to read back the gain of the RX/TX channels. The API function
 // GetGaindB has to be avoided, as it also modifies the gain, which is useless
 // and dangerous..
@@ -192,6 +234,9 @@ int GetGainRXTX(int *RXgain, int *TXgain) {
 
 std::vector<Config2HDFattr_t> getHDFAttributes(LimeConfig_t &LimeCfg) {
   std::vector<Config2HDFattr_t> HDFattr = {
+      {"dev", "Device",
+       H5::StrType(H5::PredType::C_S1, LimeCfg.device.length() + 1),
+       (void *)LimeCfg.device.c_str(), 1},
       {"sra", "SampleRate [Hz]", H5::PredType::IEEE_F32LE, &LimeCfg.srate, 1},
       {"chn", "Channel", H5::PredType::NATIVE_INT, &LimeCfg.channel, 1},
       {"rmt", "RX Matching", H5::PredType::NATIVE_INT, &LimeCfg.RX_matching, 1},
@@ -400,6 +445,8 @@ LimeConfig_t initializeLimeConfig(int Npulses) {
   // Set all the DEFAULT parameters. Command line arguments allow for
   // modification!
 
+  LimeCfg.device = "";
+
   LimeCfg.srate = 30.72e6; // sample rate of the IF DAC/ADC
   LimeCfg.channel = 0;     // channel to use,
   LimeCfg.RX_matching = 0; // RX matching network - 0 to use previous logic
@@ -830,19 +877,33 @@ int run_experiment(LimeConfig_t LimeCfg,
   if (list.size() < 1)
     return -1;
 
+  if (LimeCfg.device == "") {
+    LimeCfg.device = list[0];
+    cout << "Automatically selecting device: " << LimeCfg.device << endl;
+  }
+
   // open the first device
-  if (LMS_Open(&device, list[0].c_str(), NULL))
+  if (LMS_Open(&device, LimeCfg.device.c_str(), NULL))
     error();
 
   // Get number of channels
-  int num_rx_channels, num_tx_channels;
-  if ((num_rx_channels = LMS_GetNumChannels(device, LMS_CH_RX)) < 0)
-    error();
+  std::pair <int, int> num_channels = getDeviceChannels(device);
+  int num_rx_channels = num_channels.first;
+  int num_tx_channels = num_channels.second;
   cout << "Number of RX channels: " << num_rx_channels << endl;
-  if ((num_tx_channels = LMS_GetNumChannels(device, LMS_CH_TX)) < 0)
-    error();
   cout << "Number of TX channels: " << num_tx_channels << endl;
 
+  if (num_rx_channels < 1 || num_tx_channels < 1) {
+    cout << "No RX or TX channels found!" << endl;
+    error();
+  }
+
+  // Check if the channel selected in the config is valid
+  if (LimeCfg.channel < 0 || LimeCfg.channel >= num_rx_channels) {
+    cout << "Invalid channel selected: " << LimeCfg.channel << endl;
+    error();
+  }
+
   // check if the settings are already there
   float_type frq_read;
   if (LMS_GetLOFrequency(device, LMS_CH_RX, LimeCfg.channel, &frq_read) != 0)
@@ -1028,8 +1089,7 @@ DC_Q << endl;
       error();
 
     // get and print antenna index and name
-    if ((rx_path = LMS_GetAntenna(device, LMS_CH_RX, LimeCfg.channel)) <
-        0)
+    if ((rx_path = LMS_GetAntenna(device, LMS_CH_RX, LimeCfg.channel)) < 0)
       error();
     cout << "Manually selected RX LNA: " << rx_path << ": "
          << antenna_list[rx_path] << endl;
@@ -1060,8 +1120,7 @@ DC_Q << endl;
       error();
 
     // get and print print antenna index and name
-    if ((tx_path = LMS_GetAntenna(device, LMS_CH_TX, LimeCfg.channel)) <
-        0)
+    if ((tx_path = LMS_GetAntenna(device, LMS_CH_TX, LimeCfg.channel)) < 0)
       error();
     cout << "Manually selected TX pathway: " << tx_path << ": "
          << antenna_list[tx_path] << endl;

src/limedriver.h

@@ -28,6 +28,8 @@
 
 struct LimeConfig_t {
 
+  std::string device;
+
   float srate;
   int channel;
   int RX_matching;