This is a library that I am writing while programming my ATMega328p. I'm wanting to start out with SPI, SD Cards, and support for the FAT32 file system.
The easiest way to include this set of libraries in your project is to place this repo within your project as a submodule and build your project with CMAKE using:
add_subdirectory(lib/savor)
target_link_libraries(${EXEC_NAME} savor)A full example CMakeLists.txt for a project using this library is:
cmake_minimum_required(VERSION 3.12)
project(SampleProject)
set(CMAKE_DISABLE_SOURCE_CHANGES ON)
set(CMAKE_DISABLE_IN_SOURCE_BUILD ON)
set(CMAKE_SYSTEM_NAME Generic)
set(CMAKE_SYSTEM_PROCESSOR atmega328p)
set(CMAKE_CROSSCOMPILING 1)
set(CMAKE_C_COMPILER avr-gcc)
set(SOURCES src/main.c)
set(CMAKE_C_FLAGS "-g -Wall -mcall-prologues -mmcu=${CMAKE_SYSTEM_PROCESSOR} -Os")
set(CMAKE_EXE_LINKER_FLAGS "-Wl,-gc-sections -Wl,-relax")
add_subdirectory(lib/savor)
add_executable(${PROJECT_NAME}.elf ${SOURCES})
target_link_libraries(${PROJECT_NAME}.elf savor)
set(CMAKE_C_OBJCOPY avr-objcopy CACHE PATH "" FORCE)
add_custom_target(hex ALL DEPENDS ${PROJECT_NAME}.hex)
add_custom_command(OUTPUT ${PROJECT_NAME}.hex COMMAND ${CMAKE_C_OBJCOPY} ARGS -R .eeprom -O ihex ${PROJECT_NAME}.elf ${PROJECT_NAME}.hex DEPENDS ${PROJECT_NAME}.elf )
add_custom_target(flash DEPENDS ${PROJECT_NAME}.hex)
add_custom_command(TARGET flash USES_TERMINAL COMMAND "avrdude -c stk500v2 -P $(pavr2cmd --prog-port) -p ${CMAKE_SYSTEM_PROCESSOR} -U flash:w:${PROJECT_NAME}.hex:i")This requires avrdude and pavr2cmd. pavr2cmd is used for the Pololu AVR Programmer device.
This is the primary serial UART library. It ties into stdio so UART can be used as stdout after initialization.
Initialization is done with serial_init(ubrr). The UBRR can be calculated with the serial_ubrr(freq,baud) macro. It uses the clock frequency and target baud rate to set the serial baud.
After initialization, UART can be used as stdout so the stdio printf() function prints to it by default.
Currently the SPI module only supports master mode.
Initialization in master is done with SPI_MasterInit(). Transmission is done with SPI_Transceive(char), receiving is done with SPI_Receive().