Sensebender Micro - Serial console - reading problem

[Viktor Zeman]

I was able to upload scetch to my Sensebender Micro (1MHz) board, but I'm not able to read from console.
I read, that it is related to baud rate of console - I have tried to change the baud rate to many possible values, but none worked yet.

Could somebody help to identify my problem?

Here is the code:

#include <Wire.h>
#include "i2c.h"

#include "i2c_SI7021.h"
SI7021 si7021;


void setup()
{
    Serial.begin(9600);

    Serial.print("Probe SI7021: ");
    if (si7021.initialize()) {
      Serial.println("Sensor found!");
    } else {
        Serial.println("Sensor missing");
        while(1) {};
    }
}

void loop()
{
    static float humi, temp;

    si7021.getHumidity(humi);
    si7021.getTemperature(temp);
    si7021.triggerMeasurement();

    Serial.print("TEMP: ");
    Serial.print(temp);
    Serial.print(" HUMI: ");
    Serial.print(humi);
    Serial.println("");

}

/**<

Program size:
A1.0.5: 6896b
A1.5.7: 6590b
A1.6.3: 6484b / 499b
 */

Here is output I see:

This is what I see during compilation and uploading:

/Applications/Arduino.app/Contents/Java/arduino-builder -dump-prefs -logger=machine -hardware /Applications/Arduino.app/Contents/Java/hardware -hardware /Users/viktor/Library/Arduino15/packages -tools /Applications/Arduino.app/Contents/Java/tools-builder -tools /Applications/Arduino.app/Contents/Java/hardware/tools/avr -tools /Users/viktor/Library/Arduino15/packages -built-in-libraries /Applications/Arduino.app/Contents/Java/libraries -libraries /Users/viktor/Documents/Arduino/libraries -fqbn=MySensors:avr:MysensorsMicro:cpu=1Mhz -ide-version=10801 -build-path /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688 -warnings=none -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=/Applications/Arduino.app/Contents/Java/hardware/tools/avr -prefs=runtime.tools.avr-gcc.path=/Applications/Arduino.app/Contents/Java/hardware/tools/avr -prefs=runtime.tools.avrdude.path=/Applications/Arduino.app/Contents/Java/hardware/tools/avr -verbose /Users/viktor/Documents/Arduino/i2c_SI7021-2/i2c_SI7021-2.ino
/Applications/Arduino.app/Contents/Java/arduino-builder -compile -logger=machine -hardware /Applications/Arduino.app/Contents/Java/hardware -hardware /Users/viktor/Library/Arduino15/packages -tools /Applications/Arduino.app/Contents/Java/tools-builder -tools /Applications/Arduino.app/Contents/Java/hardware/tools/avr -tools /Users/viktor/Library/Arduino15/packages -built-in-libraries /Applications/Arduino.app/Contents/Java/libraries -libraries /Users/viktor/Documents/Arduino/libraries -fqbn=MySensors:avr:MysensorsMicro:cpu=1Mhz -ide-version=10801 -build-path /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688 -warnings=none -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=/Applications/Arduino.app/Contents/Java/hardware/tools/avr -prefs=runtime.tools.avr-gcc.path=/Applications/Arduino.app/Contents/Java/hardware/tools/avr -prefs=runtime.tools.avrdude.path=/Applications/Arduino.app/Contents/Java/hardware/tools/avr -verbose /Users/viktor/Documents/Arduino/i2c_SI7021-2/i2c_SI7021-2.ino
Using board 'MysensorsMicro' from platform in folder: /Users/viktor/Library/Arduino15/packages/MySensors/hardware/avr/1.0.1
Using core 'arduino' from platform in folder: /Applications/Arduino.app/Contents/Java/hardware/arduino/avr
Detecting libraries used...
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics  -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=1000000L -DARDUINO=10801 -DARDUINO_AVR_MICRO8 -DARDUINO_ARCH_AVR   "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/cores/arduino" "-I/Users/viktor/Library/Arduino15/packages/MySensors/hardware/avr/1.0.1/variants/micro" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/sketch/i2c_SI7021-2.ino.cpp" -o "/dev/null"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics  -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=1000000L -DARDUINO=10801 -DARDUINO_AVR_MICRO8 -DARDUINO_ARCH_AVR   "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/cores/arduino" "-I/Users/viktor/Library/Arduino15/packages/MySensors/hardware/avr/1.0.1/variants/micro" "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/libraries/Wire/src" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/sketch/i2c_SI7021-2.ino.cpp" -o "/dev/null"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics  -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=1000000L -DARDUINO=10801 -DARDUINO_AVR_MICRO8 -DARDUINO_ARCH_AVR   "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/cores/arduino" "-I/Users/viktor/Library/Arduino15/packages/MySensors/hardware/avr/1.0.1/variants/micro" "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/libraries/Wire/src" "-I/Users/viktor/Documents/Arduino/libraries/I2C-Sensor-Lib_iLib/src" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/sketch/i2c_SI7021-2.ino.cpp" -o "/dev/null"
Using cached library dependencies for file: /Applications/Arduino.app/Contents/Java/hardware/arduino/avr/libraries/Wire/src/Wire.cpp
Using cached library dependencies for file: /Applications/Arduino.app/Contents/Java/hardware/arduino/avr/libraries/Wire/src/utility/twi.c
Using cached library dependencies for file: /Users/viktor/Documents/Arduino/libraries/I2C-Sensor-Lib_iLib/src/i2c.cpp
Generating function prototypes...
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics  -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=1000000L -DARDUINO=10801 -DARDUINO_AVR_MICRO8 -DARDUINO_ARCH_AVR   "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/cores/arduino" "-I/Users/viktor/Library/Arduino15/packages/MySensors/hardware/avr/1.0.1/variants/micro" "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/libraries/Wire/src" "-I/Users/viktor/Documents/Arduino/libraries/I2C-Sensor-Lib_iLib/src" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/sketch/i2c_SI7021-2.ino.cpp" -o "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/preproc/ctags_target_for_gcc_minus_e.cpp"
"/Applications/Arduino.app/Contents/Java/tools-builder/ctags/5.8-arduino11/ctags" -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns --line-directives "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/preproc/ctags_target_for_gcc_minus_e.cpp"
Compiling sketch...
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD -mmcu=atmega328p -DF_CPU=1000000L -DARDUINO=10801 -DARDUINO_AVR_MICRO8 -DARDUINO_ARCH_AVR   "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/cores/arduino" "-I/Users/viktor/Library/Arduino15/packages/MySensors/hardware/avr/1.0.1/variants/micro" "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/libraries/Wire/src" "-I/Users/viktor/Documents/Arduino/libraries/I2C-Sensor-Lib_iLib/src" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/sketch/i2c_SI7021-2.ino.cpp" -o "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/sketch/i2c_SI7021-2.ino.cpp.o"
Compiling libraries...
Compiling library "Wire"
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/libraries/Wire/Wire.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/libraries/Wire/utility/twi.c.o
Compiling library "I2C-Sensor-Lib_iLib"
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/libraries/I2C-Sensor-Lib_iLib/i2c.cpp.o
Compiling core...
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-gcc" -c -g -x assembler-with-cpp -mmcu=atmega328p -DF_CPU=1000000L -DARDUINO=10801 -DARDUINO_AVR_MICRO8 -DARDUINO_ARCH_AVR   "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/cores/arduino" "-I/Users/viktor/Library/Arduino15/packages/MySensors/hardware/avr/1.0.1/variants/micro" "/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/cores/arduino/wiring_pulse.S" -o "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring_pulse.S.o"
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/WInterrupts.c.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/hooks.c.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring.c.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring_analog.c.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring_digital.c.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring_pulse.c.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring_shift.c.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/CDC.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/HardwareSerial.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/HardwareSerial0.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/HardwareSerial1.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/HardwareSerial2.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/HardwareSerial3.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/IPAddress.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/PluggableUSB.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/Print.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/Stream.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/Tone.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/USBCore.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/WMath.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/WString.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/abi.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/main.cpp.o
Using previously compiled file: /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/new.cpp.o
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring_pulse.S.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/WInterrupts.c.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/hooks.c.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring.c.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring_analog.c.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring_digital.c.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring_pulse.c.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/wiring_shift.c.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/CDC.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/HardwareSerial.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/HardwareSerial0.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/HardwareSerial1.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/HardwareSerial2.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/HardwareSerial3.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/IPAddress.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/PluggableUSB.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/Print.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/Stream.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/Tone.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/USBCore.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/WMath.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/WString.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/abi.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/main.cpp.o"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-ar" rcs  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/new.cpp.o"
Linking everything together...
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-gcc" -w -Os -Wl,--gc-sections -mmcu=atmega328p  -o "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/i2c_SI7021-2.ino.elf" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/sketch/i2c_SI7021-2.ino.cpp.o" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/libraries/Wire/Wire.cpp.o" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/libraries/Wire/utility/twi.c.o" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/libraries/I2C-Sensor-Lib_iLib/i2c.cpp.o" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/core/core.a" "-L/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688" -lm
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-objcopy" -O ihex -j .eeprom --set-section-flags=.eeprom=alloc,load --no-change-warnings --change-section-lma .eeprom=0  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/i2c_SI7021-2.ino.elf" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/i2c_SI7021-2.ino.eep"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-objcopy" -O ihex -R .eeprom  "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/i2c_SI7021-2.ino.elf" "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/i2c_SI7021-2.ino.hex"
Using library Wire at version 1.0 in folder: /Applications/Arduino.app/Contents/Java/hardware/arduino/avr/libraries/Wire 
Using library I2C-Sensor-Lib_iLib at version 0.8.2 in folder: /Users/viktor/Documents/Arduino/libraries/I2C-Sensor-Lib_iLib 
Sketch uses 6406 bytes (20%) of program storage space. Maximum is 30720 bytes.
Global variables use 499 bytes (24%) of dynamic memory, leaving 1549 bytes for local variables. Maximum is 2048 bytes.
/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avrdude -C/Applications/Arduino.app/Contents/Java/hardware/tools/avr/etc/avrdude.conf -v -patmega328p -carduino -P/dev/cu.usbserial-AI050RV3 -b57600 -D -Uflash:w:/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/i2c_SI7021-2.ino.hex:i 

avrdude: Version 6.3, compiled on Dec 16 2016 at 13:32:25
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "/Applications/Arduino.app/Contents/Java/hardware/tools/avr/etc/avrdude.conf"
         User configuration file is "/Users/viktor/.avrduderc"
         User configuration file does not exist or is not a regular file, skipping

         Using Port                    : /dev/cu.usbserial-AI050RV3
         Using Programmer              : arduino
         Overriding Baud Rate          : 57600
         AVR Part                      : ATmega328P
         Chip Erase delay              : 9000 us
         PAGEL                         : PD7
         BS2                           : PC2
         RESET disposition             : dedicated
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65    20     4    0 no       1024    4      0  3600  3600 0xff 0xff
           flash         65     6   128    0 yes     32768  128    256  4500  4500 0xff 0xff
           lfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           lock           0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00

         Programmer Type : Arduino
         Description     : Arduino
         Hardware Version: 3
         Firmware Version: 5.0
         Vtarget         : 0.3 V
         Varef           : 0.3 V
         Oscillator      : 28.800 kHz
         SCK period      : 3.3 us

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude: Device signature = 0x1e950f (probably m328p)
avrdude: reading input file "/var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/i2c_SI7021-2.ino.hex"
avrdude: writing flash (6406 bytes):

Writing | ################################################## | 100% 2.45s

avrdude: 6406 bytes of flash written
avrdude: verifying flash memory against /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/i2c_SI7021-2.ino.hex:
avrdude: load data flash data from input file /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/i2c_SI7021-2.ino.hex:
avrdude: input file /var/folders/zs/f1p3lxyn54g_bqr6kvdzgps00000gp/T/arduino_build_365688/i2c_SI7021-2.ino.hex contains 6406 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 2.75s

avrdude: verifying ...
avrdude: 6406 bytes of flash verified

avrdude done.  Thank you.

This are my settings in Arduino IDE:

Any idea what I should fix to be able see debug messages in console?

Thank you for help.

[tbowmo]

@Viktor-Zeman

Have you reprogrammed the fuses, so it runs at 1Mhz and not 8Mhz?

Default fuse settings in Sensebender Micro is 8Mhz

[Viktor Zeman]

Thank you for clarification, I have switched in Arduino IDE Processor to 8MHz and I can see the the serial console messages correctly now.

BTW: can you point me to the right place how to reprogram fuses?

[tbowmo]

@Viktor-Zeman

Before you change the operating frequency, you need to find out if the sensornode will be sleeping most of the time, or if it will be active..

If it's a sleeping node that will wake up once in a while, collect sensor data, and perhaps send it back to your controller, then it will not make that much difference if you run it at 1Mhz or at 8Mhz..

If we look at the datasheet for atmega328 pages 336 and 337, there are a couple of graphs, showing the approximate active current, given at different frequencies / voltages..

with a voltage of 2.7V, running at 1Mhz, the consumption is around 0.4mA, while running at 8Mhz, it's around 2mA. This seems to be a large difference, but let's take into account that the microprocessor is 8 times slower at running the same code when running at 1Mhz, than at 8Mhz, then in theory it is awake 8 times as long, when running at the lower frequency..

If we then do a rough calculation, saying that a loop takes 1 second @8Mhz, it will take 8 seconds @1Mhz. if we "transform" this to mAh, it will give a rough data like
running @1Mhz : (0.4 * 8 ) = 3.2
running @8Mhz : 2.0 * 1 = 2

And from this, we can see that running at 1Mhz, will (in theory) actually consume more power than running on 8Mhz, because the "high" current consumption will last longer at 1Mhz, than it will on 8Mhz.

When that's said.. If you want to run at 1Mhz, you can use avrdude, and a avr ISP programming dongle to program fuses. Check out this tutorial

[Viktor Zeman]

@tbowmo great answer! I agree, you are right, it has no sense to change frequency in my case. I want to measure temperature each few minutes and than sleep ...