         while (1)
             ;
     }
-    //LoRa.setSignalBandwidth(7800);
-    //LoRa.setSignalBandwidth(10400);
-    //LoRa.setSignalBandwidth(15600);
-    //LoRa.setSignalBandwidth(20800);
-    //LoRa.setSignalBandwidth(31250);
     LoRa.setSignalBandwidth(41700);
-    //LoRa.setSignalBandwidth(62500);
     LoRa.setCodingRate4(5);
     LoRa.setSpreadingFactor(6);
     LoRa.disableCrc();

    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(0, 20);
    display.print("Init...");

    // Visualize the result.
    display.display();
    delay(1500);
}

void send(int msec)
{
    // Compute preamble length of required duration.
    // To measure the timing, use plen = msec.

//
#define FREQ_HZ 433575000   // 433.575 MHz

//
// On Lora32 module, OLED reset signal is connected to gpio16.
//
Adafruit_SSD1306 display(16);

//
// Timing for 10 words per minute.
//
int dot_msec   = 120;
int dash_msec  = 360;
int pause_msec = 360;
int space_seen;

void setup()
{
