Not declared in this scope. I'm stuck no matter what I try

This is probably simple but I'm banging my head against the wall for sometime now. I'm trying to split a simple program into multiple files so I can add to it. I'm trying to logically split it into parts. If anyone can give me some pointers as to my mistakes that'd be awesome.

Main.cpp

#include <Arduino.h> #include "measure.h" #include "LoRa.h" void setup() { Serial.begin(9600); // STart serial for monitoring/debugging Serial2.begin(9600); // Start 2nd serial interface for use with EBYTE module Serial.println("Starting Reader"); Serial.println(Transceiver.init()); // This init will set the pinModes for you Transceiver.PrintParameters(); // Display parameters of EBYTE (Can be changed. See example sketches) } //================================================================= //======LOOP======================================================= //================================================================= void loop() { measure(); // Take measurements delay(1000); // For testing. Will not exist in final } 

measure.cpp

// Takes various measurements, updates struct and sends to receiver #include <Arduino.h> #include "measure.h" #include "MyData.h" #include "LoRa.h" unsigned long Last; void measure() { // measure some data and save to the structure MyData.Count++; MyData.Bits = analogRead(A0); MyData.Volts = MyData.Bits * (5.0 / 1024.0); // Send struct Transceiver.SendStruct(&MyData, sizeof(MyData)); // Let us know something was sent Serial.print("Sending: "); Serial.println(MyData.Count); } 

measure.h

#ifndef MEASURE_H #define MEASURE_H #include <Arduino.h> #include "LoRa.h" void measure(); #endif 

LoRa.cpp

// Somewhere to define/declare everything to do with the Ebyte E32 LoRa module #include <Arduino.h> #include "EBYTE.h" #include "LoRa.h" #define PIN_RX 16 // Serial2 RX (connect this to the EBYTE Tx pin) #define PIN_TX 17 // Serial2 TX pin (connect this to the EBYTE Rx pin) #define PIN_M0 4 // D4 on the board (possibly pin 24) #define PIN_M1 22 // D2 on the board (possibly called pin 22) #define PIN_AX 21 // D15 on the board (possibly called pin 21) // create the transceiver object, passing in the serial and pins EBYTE Transceiver(&Serial2, PIN_M0, PIN_M1, PIN_AX); 

LoRa.h

#ifndef LORA_H #define LORA_H #include "Arduino.h" #endif 

MyData.h

#ifndef MYDATA_H #define MYDATA_H struct DATA { unsigned long Count; int Bits; float Volts; float Temp; } MyData; #endif 

ERRORS

src\main.cpp: In function 'void setup()': src\main.cpp:45:20: error: 'Transceiver' was not declared in this scope Serial.println(Transceiver.init()); // This init will set the pinModes for you ^ src\measure.cpp: In function 'void measure()': src\measure.cpp:18:5: error: 'Transceiver' was not declared in this scope Transceiver.SendStruct(&MyData, sizeof(MyData)); ^ *** [.pio\build\esp32doit-devkit-v1\src\measure.cpp.o] Error 1 *** [.pio\build\esp32doit-devkit-v1\src\main.cpp.o] Error 1 

Thanks!!

1 Answer

You are creating a Transceiver object in LoRa.cpp, but it hasn't been made accessible to your measure.cpp file. To reach an object that is in file scope in a different file, you add extern in the declaration:

extern EBYTE Transceiver; 

Also, for the measure.cpp file to understand what kind of object Transceiver is (for example which methods it contains) you should include the EBYTE header in measure.cpp:

#include "EBYTE.h" 

An example using the EBYTE code.

For example:

#include <Arduino.h> #include "EBYTE.h" #include "measure.h" #include "MyData.h" #include "LoRa.h" unsigned long Last; extern EBYTE Transceiver; void measure() {