diff --git a/RetroWiFiModem/RetroWiFiModem.ino b/RetroWiFiModem/RetroWiFiModem.ino
index b3b23ef..d4aaa47 100644
--- a/RetroWiFiModem/RetroWiFiModem.ino
+++ b/RetroWiFiModem/RetroWiFiModem.ino
@@ -204,7 +204,10 @@ void doAtCmds(char *atCmd) {
                } else if( !strncasecmp(atCmd, "DS", 2) && len == 3 ) {
                   // speed dial a number
                   atCmd = speedDialNumber(atCmd + 2);
-               } else if( !strncasecmp(atCmd, "H", 1) || !strncasecmp(atCmd, "H0", 2) ) {
+               } else if( !strncasecmp(atCmd, "H0", 2) ) {
+                  // hang up call
+                  atCmd = hangup(atCmd + 2);
+               } else if( !strncasecmp(atCmd, "H", 1) && !isDigit(atCmd[1]) ) {
                   // hang up call
                   atCmd = hangup(atCmd + 1);
                } else if( !strncasecmp(atCmd, "&Z", 2) && isDigit(atCmd[2]) ) {
diff --git a/RetroWiFiModem/at_basic.h b/RetroWiFiModem/at_basic.h
index f53a0ad..dc99a5a 100644
--- a/RetroWiFiModem/at_basic.h
+++ b/RetroWiFiModem/at_basic.h
@@ -289,9 +289,6 @@ char *httpGet(char *atCmd) {
 // ATH go offline (if connected to a host)
 //
 char *hangup(char *atCmd) {
-   if( atCmd[0] ) {
-      ++atCmd;
-   }
    if( tcpClient.connected() ) {
       endCall();
    } else {
diff --git a/RetroWiFiModem/support.h b/RetroWiFiModem/support.h
index 3744f2b..d4dc1be 100644
--- a/RetroWiFiModem/support.h
+++ b/RetroWiFiModem/support.h
@@ -504,17 +504,17 @@ SerialConfig getSerialConfig(void) {
    uint8_t serialConfig = 0;
    switch( settings.dataBits ) {
       case 5:
-         serialConfig = serialConfig = UART_NB_BIT_5 | (~UART_NB_BIT_MASK & serialConfig);
+         serialConfig = UART_NB_BIT_5 | (~UART_NB_BIT_MASK & serialConfig);
          break;
       case 6:
-         serialConfig = serialConfig = UART_NB_BIT_6 | (~UART_NB_BIT_MASK & serialConfig);
+         serialConfig = UART_NB_BIT_6 | (~UART_NB_BIT_MASK & serialConfig);
          break;
       case 7:
-         serialConfig = serialConfig = UART_NB_BIT_7 | (~UART_NB_BIT_MASK & serialConfig);
+         serialConfig = UART_NB_BIT_7 | (~UART_NB_BIT_MASK & serialConfig);
          break;
       case 8:
       default:
-         serialConfig = serialConfig = UART_NB_BIT_8 | (~UART_NB_BIT_MASK & serialConfig);
+         serialConfig = UART_NB_BIT_8 | (~UART_NB_BIT_MASK & serialConfig);
          break;
    }
    switch( settings.parity ) {
diff --git a/bin/RetroWiFiModem.d1r2_or_d1mini.bin b/bin/RetroWiFiModem.d1r2_or_d1mini.bin
index 9f9e955..14cf681 100644
Binary files a/bin/RetroWiFiModem.d1r2_or_d1mini.bin and b/bin/RetroWiFiModem.d1r2_or_d1mini.bin differ