Add skeleton for SerialLink

Software/Software.ino

@@ -17,7 +17,9 @@
 
 // Interval settings
 int intervalUpdateValues = 4800;  // Interval at which to update inverter values / Modbus registers
+const int interval1 = 1;          // Interval for 1ms tasks
 const int interval10 = 10;        // Interval for 10ms tasks
+unsigned long previousMillis1ms = 0;
 unsigned long previousMillis10ms = 50;
 unsigned long previousMillisUpdateVal = 0;
 
@@ -129,6 +131,9 @@ void loop() {
 #ifdef DUAL_CAN
   receive_can2();
 #endif
+#ifdef SERIAL_LINK_TRANSMITTER_INVERTER
+  receive_serial();
+#endif
 
   // Process
   if (millis() - previousMillis10ms >= interval10)  // Every 10ms
@@ -151,6 +156,9 @@ void loop() {
 #ifdef DUAL_CAN
   send_can2();
 #endif
+#ifdef SERIAL_LINK_RECEIVER_FROM_BATTERY
+  send_serial();
+#endif
 }
 
 // Initialization functions
@@ -218,6 +226,13 @@ void init_modbus() {
   pinMode(PIN_5V_EN, OUTPUT);
   digitalWrite(PIN_5V_EN, HIGH);
 
+#if defined(SERIAL_LINK_RECEIVER_FROM_BATTERY) || defined(SERIAL_LINK_TRANSMITTER_INVERTER)
+  Serial2.begin(9600);  // If the Modbus RTU port will be used for serial link
+#if defined(BYD_MODBUS) || defined(LUNA2000_MODBUS)
+#error Modbus pins cannot be used for Serial and Modbus at the same time!
+#endif
+#endif
+
 #ifdef BYD_MODBUS
   // Init Static data to the RTU Modbus
   handle_static_data_modbus_byd();
@@ -384,6 +399,22 @@ void send_can() {
 #endif
 }
 
+void send_serial() {
+  static unsigned long currentMillis = millis();
+  if (currentMillis - previousMillis1ms >= interval1) {
+    previousMillis1ms = currentMillis;
+    manageSerialLinkReceiver();
+  }
+}
+
+void receive_serial() {
+  static unsigned long currentMillis = millis();
+  if (currentMillis - previousMillis1ms >= interval1) {
+    previousMillis1ms = currentMillis;
+    manageSerialLinkTransmitter();
+  }
+}
+
 #ifdef DUAL_CAN
 void receive_can2() {  // This function is similar to receive_can, but just takes care of inverters in the 2nd bus.
   // Depending on which inverter is selected, we forward this to their respective CAN routines

Software/USER_SETTINGS.h

@@ -42,5 +42,7 @@
 //#define CONTACTOR_CONTROL     //Enable this line to have pins 25,32,33 handle automatic precharge/contactor+/contactor- closing sequence
 //#define PWM_CONTACTOR_CONTROL //Enable this line to use PWM logic for contactors, which lower power consumption and heat generation
 //#define DUAL_CAN              //Enable this line to activate an isolated secondary CAN Bus using add-on MCP2515 controller (Needed for FoxESS inverters)
+#define SERIAL_LINK_RECEIVER_FROM_BATTERY  //Enable this line to send battery data over Modbus pins to another Lilygo
+#define SERIAL_LINK_TRANSMITTER_INVERTER  //Enable this line to receive battery data over Modbus pins from another Lilygo
 
 #endif