HELP Error Compiling Boards

Using Arduino Programming Questions
1

Arduino: 1.8.20 Hourly Build 2022/04/25 09:33 (Windows 10), Board: "DOIT ESP32 DEVKIT V1, 80MHz, 921600, None"

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3/tools/sdk/esp32/qspi_qspi\libfreertos.a(port_common.c.obj):(.literal.main_task+0x14): undefined reference to `app_main'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3/tools/sdk/esp32/qspi_qspi\libfreertos.a(port_common.c.obj): in function `main_task':

/home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/freertos/port/port_common.c:118: undefined reference to `app_main'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z5setupv+0xc): undefined reference to `Serial'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z5setupv+0x54): undefined reference to `HardwareSerial::begin(unsigned long, unsigned int, signed char, signed char, bool, unsigned long, unsigned char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z5setupv+0x58): undefined reference to `String::String(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z5setupv+0x5c): undefined reference to `String::~String()'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z5setupv+0x60): undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z5setupv+0x64): undefined reference to `String::String(String const&)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z5setupv+0x68): undefined reference to `pinMode'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z4loopv+0x28): undefined reference to `digitalRead'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z4loopv+0x30): undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z4loopv+0x34): undefined reference to `Print::println(__FlashStringHelper const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z4loopv+0x38): undefined reference to `Print::print(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z4loopv+0x3c): undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o:(.literal._Z4loopv+0x40): undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o: in function `setup()':

C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:31: undefined reference to `HardwareSerial::begin(unsigned long, unsigned int, signed char, signed char, bool, unsigned long, unsigned char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:33: undefined reference to `String::String(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:33: undefined reference to `String::~String()'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:34: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:36: undefined reference to `String::String(String const&)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:36: undefined reference to `String::~String()'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:39: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:46: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:55: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:59: undefined reference to `pinMode'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:60: undefined reference to `pinMode'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:61: undefined reference to `pinMode'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:42: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:36: undefined reference to `String::~String()'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o: in function `loop()':

C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:65: undefined reference to `digitalRead'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:74: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:77: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:84: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:89: undefined reference to `Print::println(__FlashStringHelper const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:90: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:97: undefined reference to `Print::print(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:97: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:98: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:99: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:100: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:102: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:103: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:104: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:105: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:107: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:108: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:110: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:113: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:114: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:116: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:117: undefined reference to `digitalRead'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:129: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o: in function `PString::PString(char*, unsigned int)':

C:\Users\acer\OneDrive\Documents\Arduino\libraries\PString/PString.h:46: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\libraries\PString/PString.h:47: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o: in function `loop()':

C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:136: undefined reference to `Print::println(__FlashStringHelper const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:138: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:153: undefined reference to `Print::print(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:154: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:155: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:157: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:158: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:159: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:160: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:161: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:162: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:163: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:164: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:165: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:166: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:169: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:169: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:174: undefined reference to `digitalRead'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:181: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:183: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:186: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:190: undefined reference to `Print::println(__FlashStringHelper const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o: in function `PString::PString(char*, unsigned int)':

C:\Users\acer\OneDrive\Documents\Arduino\libraries\PString/PString.h:46: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o: in function `loop()':

C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:205: undefined reference to `Print::print(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:207: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:208: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:210: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:211: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:214: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:215: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:218: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:218: undefined reference to `Print::print(int, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:219: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:220: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:221: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:222: undefined reference to `Print::print(char)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:223: undefined reference to `Print::print(unsigned char, int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:224: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:226: undefined reference to `digitalRead'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:232: undefined reference to `Print::println(__FlashStringHelper const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o: in function `_GLOBAL__sub_I_RTC':

C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:240: undefined reference to `String::String(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o: in function `__static_initialization_and_destruction_0':

C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:242: undefined reference to `String::String(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o: in function `_GLOBAL__sub_D_RTC':

C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:246: undefined reference to `String::~String()'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: sketch\sketch_may17a.ino.cpp.o: in function `__static_initialization_and_destruction_0':

C:\Users\acer\OneDrive\Documents\Arduino\sketch_may17a/sketch_may17a.ino:246: undefined reference to `String::~String()'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o:(.literal._ZN15BluetoothSerial5flushEv+0x0): undefined reference to `delay'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o:(.literal._ZN15BluetoothSerialC2Ev+0xc): undefined reference to `String::operator=(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o:(.literal._ZN15BluetoothSerial5beginE6Stringb+0x28): undefined reference to `String::operator=(String const&)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `BluetoothSerial::~BluetoothSerial()':

C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\BluetoothSerial\src/BluetoothSerial.cpp:746: undefined reference to `String::~String()'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `BluetoothSerial::flush()':

C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\BluetoothSerial\src/BluetoothSerial.cpp:862: undefined reference to `delay'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `BluetoothSerial::BluetoothSerial()':

C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\BluetoothSerial\src/BluetoothSerial.cpp:784: undefined reference to `String::String(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\BluetoothSerial\src/BluetoothSerial.cpp:786: undefined reference to `String::operator=(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\BluetoothSerial\src/BluetoothSerial.cpp:784: undefined reference to `String::~String()'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `BluetoothSerial::begin(String, bool)':

C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\BluetoothSerial\src/BluetoothSerial.cpp:801: undefined reference to `String::operator=(String const&)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o:(.rodata._ZTV15BluetoothSerial[_ZTV15BluetoothSerial]+0x2c): undefined reference to `Stream::readBytes(char*, unsigned int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o:(.rodata._ZTV15BluetoothSerial[_ZTV15BluetoothSerial]+0x34): undefined reference to `Stream::readString()'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\PString\PString.cpp.o:(.rodata._ZTV7PString[_ZTV7PString]+0x14): undefined reference to `Print::write(unsigned char const*, unsigned int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\BluetoothSerial\BTScanResultsSet.cpp.o:(.literal._ZN16BTScanResultsSet4dumpEP5Print+0x10): undefined reference to `Print::printf(char const*, ...)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\BluetoothSerial\BTScanResultsSet.cpp.o: in function `BTScanResultsSet::dump(Print*)':

C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\BluetoothSerial\src/BTScanResultsSet.cpp:38: undefined reference to `Print::printf(char const*, ...)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\BluetoothSerial\src/BTScanResultsSet.cpp:42: undefined reference to `Print::printf(char const*, ...)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\BluetoothSerial\src/BTScanResultsSet.cpp:44: undefined reference to `Print::printf(char const*, ...)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\BluetoothSerial\src/BTScanResultsSet.cpp:46: undefined reference to `Print::println(char const*)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Adafruit_Thermal_Printer_Library\Adafruit_Thermal.cpp.o:(.literal._ZN16Adafruit_Thermal10timeoutSetEm+0x0): undefined reference to `micros'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Adafruit_Thermal_Printer_Library\Adafruit_Thermal.cpp.o: in function `Adafruit_Thermal::timeoutSet(unsigned long)':

C:\Users\acer\OneDrive\Documents\Arduino\libraries\Adafruit_Thermal_Printer_Library/Adafruit_Thermal.cpp:78: undefined reference to `micros'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Adafruit_Thermal_Printer_Library\Adafruit_Thermal.cpp.o: in function `Adafruit_Thermal::timeoutWait()':

C:\Users\acer\OneDrive\Documents\Arduino\libraries\Adafruit_Thermal_Printer_Library/Adafruit_Thermal.cpp:84: undefined reference to `digitalRead'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\OneDrive\Documents\Arduino\libraries\Adafruit_Thermal_Printer_Library/Adafruit_Thermal.cpp:87: undefined reference to `micros'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Adafruit_Thermal_Printer_Library\Adafruit_Thermal.cpp.o: in function `Adafruit_Thermal::wake()':

C:\Users\acer\OneDrive\Documents\Arduino\libraries\Adafruit_Thermal_Printer_Library/Adafruit_Thermal.cpp:592: undefined reference to `delay'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Adafruit_Thermal_Printer_Library\Adafruit_Thermal.cpp.o: in function `Adafruit_Thermal::begin(unsigned short)':

C:\Users\acer\OneDrive\Documents\Arduino\libraries\Adafruit_Thermal_Printer_Library/Adafruit_Thermal.cpp:198: undefined reference to `pinMode'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Adafruit_Thermal_Printer_Library\Adafruit_Thermal.cpp.o:(.rodata._ZTV16Adafruit_Thermal[_ZTV16Adafruit_Thermal]+0x14): undefined reference to `Print::write(unsigned char const*, unsigned int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o:(.literal._ZN7TwoWire5beginEiij+0x0): undefined reference to `i2cIsInit'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o:(.literal._ZN7TwoWire5beginEiij+0x8): undefined reference to `i2cInit'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o:(.literal._ZN7TwoWire3endEv+0x0): undefined reference to `i2cSlaveDeinit'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o:(.literal._ZN7TwoWire3endEv+0x4): undefined reference to `i2cDeinit'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o:(.literal._ZN7TwoWire15endTransmissionEb+0x0): undefined reference to `i2cWrite'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o:(.literal._ZN7TwoWire11requestFromEtjb+0x0): undefined reference to `i2cWriteReadNonStop'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o:(.literal._ZN7TwoWire11requestFromEtjb+0x4): undefined reference to `i2cRead'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o: in function `TwoWire::begin(int, int, unsigned int)':

C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\Wire\src/Wire.cpp:221: undefined reference to `i2cIsInit'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\Wire\src/Wire.cpp:211: undefined reference to `i2cInit'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o: in function `TwoWire::end()':

C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\Wire\src/Wire.cpp:234: undefined reference to `i2cSlaveDeinit'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\Wire\src/Wire.cpp:248: undefined reference to `i2cIsInit'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\Wire\src/Wire.cpp:239: undefined reference to `i2cDeinit'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o: in function `TwoWire::endTransmission(bool)':

C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\Wire\src/Wire.cpp:336: undefined reference to `i2cWrite'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o: in function `TwoWire::requestFrom(unsigned short, unsigned int, bool)':

C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\Wire\src/Wire.cpp:376: undefined reference to `i2cWriteReadNonStop'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: C:\Users\acer\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.3\libraries\Wire\src/Wire.cpp:387: undefined reference to `i2cRead'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o:(.rodata._ZTV7TwoWire[_ZTV7TwoWire]+0x2c): undefined reference to `Stream::readBytes(char*, unsigned int)'

c:/users/acer/appdata/local/arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: libraries\Wire\Wire.cpp.o:(.rodata._ZTV7TwoWire[_ZTV7TwoWire]+0x34): undefined reference to `Stream::readString()'

collect2.exe: error: ld returned 1 exit status

exit status 1

Error compiling for board DOIT ESP32 DEVKIT V1.

2

In general, it is best to use the latest SUPPORTED version of Arduino (1.8.19) unless you are trying to test a fix that is in the latest hourly build.

It looks like something has gone terribly wrong with your installation of either Arduino or the ESP32 support.

3

Install Arduino IDE 1.8.19 or Arduino IDE 2.0 RC and then install the package core for your board, see Getting Started with the ESP32 Development Board | Random Nerd Tutorials.
Make sure that you use a data USB cable and avoid using USB 3.0 port or USB hub.

4

Why ?

5

USB 3.0 port cause some issues. https://support.arduino.cc/hc/en-us/articles/360019546000-My-sketch-compiles-but-does-not-upload-or-the-upload-button-is-grayed-out

6

That article seems to relate to using the Arduino Create Agent

If the official Arduino advice is not to use a USB hub or USB 3.0 when not using the Create Agent then lots of users will be screwed

7

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