Here I'll let some experiments with bare metal in AVR microcontrollers.

In this repository, all the examples and stuff will be exclusively to ATmega328P (which is a microcontroller from AVR family) and Arduino Uno.

The code here are focused to re-create the functions provided by the Arduino Library, such as pinMode, digitalWrite, digitalRead, delay, etc. The examples in examples dir use those functions.

• set_pin_mode(): sets the pin mode (INPUT or OUTPUT).
• digital_write(): writes LOW or HIGH in the given pin.
• digital_read(): reads LOW or HIGH from the given pin.
• delay_ms(): delays in the given ms.
• delay_us(): delays in the given us.
• uart_init(): initializes the UART with the given baudrate.
• uart_sendbyte(): sends a byte through UART.
• uart_recvbyte(): receives a byte through UART.
• uart_puts(): sends a string through UART.
• uart_gets(): receives a string through UART.

Firstly, you'll need these tools:

• avr-gcc
• avrdude

Compiling the standard lib and the examples:

make

After that, you can upload the examples inside the build/examples/ dir:

./upload [SERIALPORT] build/examples/*.bin

SERIALPORT is platform dependent, but in my case is something like /dev/ttyUSB0.

Any .bin in build/examples can be uploaded, but check and modify the code in examples if necessary.

Remember: only works on ATmega328P

• Blinking LED
• Toggle LED with Push-up Button
• 7 segment display
• UART Send String

• Delay functions with internal timers
• UART support