Revert mechanism for serial generation for Arduino AVRs

src/Config.cpp

@@ -431,6 +431,11 @@ void OnGetConfig()
 
 void OnGetInfo()
 {
+    // read the serial number and generate if 1st start up, was before in ResetBoard()
+    // moved to this position as the time to generate a serial number in ResetBoard() is always the same
+    // OnGetInfo() is called from the connector and the time is very likely always different
+    // Therefore millis() can be used for randomSeed
+    generateSerial(false);
     setLastCommandMillis();
     cmdMessenger.sendCmdStart(kInfo);
     cmdMessenger.sendCmdArg(F(MOBIFLIGHT_TYPE));
@@ -448,45 +453,58 @@ bool getStatusConfig()
 // ************************************************************
 // serial number handling
 // ************************************************************
+void generateRandomSerial()
+{
+    randomSeed(millis());
+    sprintf(serial, "SN-%03x-%03x", (unsigned int)random(4095), (unsigned int)random(4095));
+    MFeeprom.write_block(MEM_OFFSET_SERIAL, serial, MEM_LEN_SERIAL);
+}
+
+void generateUniqueSerial()
+{
+    sprintf(serial, "SN-");
+    for (size_t i = 0; i < UniqueIDsize; i++) {
+        sprintf(&serial[3 + i * 2], "%02X", UniqueID[i]);
+    }
+}
+
 void generateSerial(bool force)
 {
     if (force) {
-#if defined(ARDUINO_ARCH_AVR)
-        // A serial number is forced to generated from the user
-        // It is very likely that the reason is a double serial number as the UniqueID for AVR's must not be Unique
-        // so generate one acc. the old style and use millis() for seed
-        randomSeed(millis());
-        sprintf(serial, "SN-%03x-", (unsigned int)random(4095));
-        sprintf(&serial[7], "%03x", (unsigned int)random(4095));
-        MFeeprom.write_block(MEM_OFFSET_SERIAL, serial, MEM_LEN_SERIAL);
-#endif
+        // A serial number is forced to generate
+        // generate a serial number acc. the old style also for the Pico
+        generateRandomSerial();
         return;
     }
 
+    // A serial number according old style is already generated and saved to the eeprom
     if (MFeeprom.read_byte(MEM_OFFSET_SERIAL) == 'S' && MFeeprom.read_byte(MEM_OFFSET_SERIAL + 1) == 'N') {
-        // A serial number according old style is already generated and saved to the eeprom
-        // So keep it to avoid a connector message with orphaned board
         MFeeprom.read_block(MEM_OFFSET_SERIAL, serial, MEM_LEN_SERIAL);
         return;
     }
 
-    // Read the uniqueID and use it as serial numnber
-    sprintf(serial, "SN-");
-    for (size_t i = 0; i < UniqueIDsize; i++) {
-        if (UniqueID[i] < 0x10) {
-            sprintf(&serial[3 + i * 2], "0%X", UniqueID[i]);
-        } else {
-            sprintf(&serial[3 + i * 2], "%X", UniqueID[i]);
-        }
+    // A uniqueID is already generated and saved to the eeprom
+    if (MFeeprom.read_byte(MEM_OFFSET_SERIAL) == 'I' && MFeeprom.read_byte(MEM_OFFSET_SERIAL + 1) == 'D') {
+        generateUniqueSerial();
+        return;
     }
 
-    if (MFeeprom.read_byte(MEM_OFFSET_SERIAL) != 'I' && MFeeprom.read_byte(MEM_OFFSET_SERIAL + 1) != 'D') {
-        // Coming here it's the first start up of the board and no serial number or UniqueID is available
-        // mark this in the eeprom that a UniqueID is used on first start up
-        MFeeprom.write_block(MEM_OFFSET_SERIAL, "ID", 2);
-        // Set first byte of config to 0x00 to ensure with empty config on 1st start up
-        MFeeprom.write_byte(MEM_OFFSET_CONFIG, 0x00);
-    }
+    // Coming here no UniqueID and no serial number is available, so it's the first start up of a board
+#if defined(ARDUINO_ARCH_AVR)
+    // Generate a serial number for AVR's
+    // To have not always the same starting point for the random generator, millis() are
+    // used as starting point. It is very unlikely that the time between flashing the firmware
+    // and getting the command to send the info's to the connector is always the same.
+    generateRandomSerial();
+#elif defined(ARDUINO_ARCH_RP2040)
+    // Read the uniqueID for Pico's and use it as serial number
+    generateUniqueSerial();
+    // mark this in the eeprom that a UniqueID is used on first start up for Pico's
+    MFeeprom.write_block(MEM_OFFSET_SERIAL, "ID", 2);
+#endif
+    // Set first byte of config to 0x00 to ensure empty config on 1st start up
+    // Otherwise the complete length of the config will be send with 0xFF (empty EEPROM)
+    MFeeprom.write_byte(MEM_OFFSET_CONFIG, 0x00);
 }
 
 void OnGenNewSerial()

src/mobiflight.cpp

@@ -140,7 +140,6 @@ void updatePowerSaving()
 // ************************************************************
 void ResetBoard()
 {
-    generateSerial(false);
     setLastCommandMillis();
     restoreName();
     loadConfig();