Doc: Created meaningful readme

CMakeLists.txt

@@ -6,8 +6,9 @@ project(vfdprog C)
 set(CMAKE_C_COMPILER avr-gcc)
 set(OBJCOPY avr-objcopy)
 set(TARGET_CPU atmega88)
+set(F_CPU 8000000UL)
 
-add_compile_definitions("__AVR_${TARGET_CPU}__" "F_CPU=8000000UL")
+add_compile_definitions("__AVR_${TARGET_CPU}__" "F_CPU=${F_CPU}")
 include_directories(/usr/lib/avr/include)
 set(CMAKE_C_FLAGS "-Os -mcall-prologues -mmcu=${TARGET_CPU} -Wall")
 

README.md

@@ -1,5 +1,51 @@
 # AT-VFD
-Controlling a VFD with an ATMega88
+Goal: Controlling a VFD with an Atmel microcontroller
+<br>
+Compatible hardware: [Princeton PT6302](https://pdf1.alldatasheet.com/datasheet-pdf/view/391603/PTC/PT6302.html), [OKI ML9208](https://pdf1.alldatasheet.com/datasheet-pdf/view/135132/OKI/ML9208.html) (note that in naming the PT6302 datasheeet is followed)
+<br>
+Project is work in progress, breaing changes might come in the future
 
-# PROJECT INCOMPLETE! 
-Find documentation in the header file
+## Using the driver library
+Modify PT6302.h
+- Re-define the macro `DISPLAY_DIGITS` to the number of digits on your VFD
+- replace the pins in `enum pins` with th pins you have wired to the given controller interface pins 
+
+Include the PT6302.h in your application and use the functions to display whatever you want.
+
+## Building
+Use **either** [GNU make](#GNU make) or [CMake](#CMake) whichever you're familiar with.
+### Dependencies
+The project uses `avr-libc` as well as `avr-gcc`, please install the packages neccesary. For building you need either GNU make or CMake.
+If you're using CLion, it should automatically pick up on `CMakeLists.txt`, but you still need to modify it to your hardware.
+
+### GNU make
+Modify `Makefile`:
+- Change `MCU` to your target microcontroller
+- Change `F_CPU` to the frequency of your microcontroller's clock source
+- In `CFLAGS` make sure that the path after `I` is where you have your avr c libraries
+- `TARGET` should be the project name (or keep it as is, it doesn't matter)
+- In `SRCS` replace `main` with your application's c and header files
+- Change the avrdude command in `flash` to the device and port you're using for downloading the firmware
+
+Then in the project directory run 
+```shell
+make && make flash
+``` 
+to compile and download firmware.
+
+### CMake
+Modify `CMakeLists.txt`:
+- Change `TARGET_CPU` to your target microcontroller (in the `set` statement)
+- Change `F_CPU` to the frequency of your microcontroller's clock source (in the `set` statement)
+- Put the full path to your avr c libraries int the `include_directories` statement
+- Replace `main.c` with the name of your c source and header files in the `add_executable` statement 
+- Change the avrdude command in the custom targeg`FLASH` to the device and port you're using for downloading the firmware
+
+Create a building directory for cmake and change into it: 
+```shell
+ mkdir cmake-build-debug && cd cmake-build-debug
+ ```
+Then compile, link and flash:
+```shell
+cmake ..  && cmake --build . -t FLASH
+```