3 files changed, 26 insertions, 4 deletions
diff --git a/glcddrivers/port.c b/glcddrivers/port.c
index 2c123e1..bf5df86 100644
--- a/glcddrivers/port.c
+++ b/glcddrivers/port.c
@@ -340,9 +340,6 @@ int cSerialPort::Open(const char * device)
     options.c_cflag &= ~CSIZE;
     options.c_cflag |= CS8;
 
-    // No "hangup" (prevents Arduino firmware reboots)
-    options.c_cflag &= ~HUPCL;
-
     // No hardware flow control
     options.c_cflag &= ~CRTSCTS;
 
@@ -392,6 +389,19 @@ void cSerialPort::SetBaudRate(int speed)
     }
 }
 
+// Configures the serial port to not send a "hangup" signal.
+// Returns true if the flag was set and had to be removed and false otherwise.
+bool cSerialPort::DisableHangup()
+{
+    struct termios options;
+    tcgetattr(fd, &options);
+    if (!(options.c_cflag & HUPCL))
+        return false;
+    options.c_cflag &= ~HUPCL;
+    tcsetattr(fd, TCSANOW, &options);
+    return true;
+}
+
 int cSerialPort::ReadData(unsigned char * data)
 {
     if (fd == -1)
diff --git a/glcddrivers/port.h b/glcddrivers/port.h
index fc97293..9280661 100644
--- a/glcddrivers/port.h
+++ b/glcddrivers/port.h
@@ -91,6 +91,7 @@ public:
     int Open(const char * device);
     int Close();
     void SetBaudRate(int speed);
+    bool DisableHangup();
 
     int ReadData(unsigned char * data);
     void WriteData(unsigned char data);
diff --git a/glcddrivers/usbserlcd.c b/glcddrivers/usbserlcd.c
index 47d1e7e..44efb31 100644
--- a/glcddrivers/usbserlcd.c
+++ b/glcddrivers/usbserlcd.c
@@ -12,6 +12,7 @@
 #include <syslog.h>
 #include <cstring>
 #include <cstdlib>
+#include <unistd.h>
 
 #include "common.h"
 #include "config.h"
@@ -19,6 +20,8 @@
 #include "usbserlcd.h"
 #include "stdint.h"
 
+const int BAUD_RATE = 150000;
+const int BOOT_TIME = 300000;
 
 namespace GLCD
 {
@@ -73,13 +76,21 @@ int cDriverUSBserLCD::Init()
     if (port->Open(config->device.c_str()) != 0)
         return -1;
 
-    port->SetBaudRate(150000);
+    port->SetBaudRate(BAUD_RATE);
 
     *oldConfig = *config;
 
     // clear display
     Clear();
 
+    // Disable the "hangup" signal to prevent Arduino reboots on connect.
+    // We can't catch the first reboot with this (Hangup flag was set).
+    // In this case, wait some milliseconds and do a full refresh.
+    if (port->DisableHangup()) {
+        usleep(BOOT_TIME);
+        Refresh(true);
+    }
+
     syslog(LOG_INFO, "%s: USBserLCD initialized.\n", config->name.c_str());
     return 0;
 }