Fix: transition to make because CMake used the wrong linker

Credit to Łukasz Podkalicki for Makefile

.gitignore

@@ -1,2 +1,4 @@
 cmake-build-debug/*
 .idea/*
+main.bin
+main.hex

CMakeLists.txt

@@ -1,21 +0,0 @@
-cmake_minimum_required(VERSION 3.21)
-set(CMAKE_SYSTEM_NAME Generic)
-set(CMAKE_C_STANDARD 99)
-project(vfdprog C)
-
-set(CMAKE_C_COMPILER avr-gcc)
-set(TARGET_CPU ATmega88)
-
-add_compile_definitions("__AVR_${TARGET_CPU}__")
-include_directories(/usr/lib/avr/include)
-set(CMAKE_C_FLAGS "-O3 -Wall")
-
-add_link_options(-Wl,--print-memory-usage)
-add_executable(${PROJECT_NAME} main.c PT6302.c PT6302.h)
-
-add_custom_target(
-        FLASH
-        avrdude -p ${TARGET_CPU} -c USBasp -v -U flash:w:${PROJECT_BINARY_DIR}/${PROJECT_NAME}:a
-        DEPENDS ${PROJECT_NAME}
-        COMMENT "Flash to ${TARGET_CPU}"
-)

Makefile

@@ -0,0 +1,18 @@
+# Credits to Łukasz Podkalicki: https://blog.podkalicki.com/how-to-compile-and-burn-the-code-to-avr-chip-on-linuxmacosxwindows/
+MCU=atmega88
+F_CPU=8000000UL
+CC=avr-gcc
+OBJCOPY=avr-objcopy
+CFLAGS=-std=c99 -Wall -g -O3 -mmcu=${MCU} -DF_CPU=${F_CPU} -I/usr/lib/avr/include/
+TARGET=main
+SRCS=main.c PT6302.c PT6302.h
+	
+all:
+	${CC} ${CFLAGS} -o ${TARGET}.bin ${SRCS}
+	${OBJCOPY} -j .text -j .data -O ihex ${TARGET}.bin ${TARGET}.hex	
+	
+flash:
+	avrdude -p ${MCU} -c usbasp -U flash:w:${TARGET}.hex:i -F -P usb
+
+clean:
+	rm -f *.bin *.hex

PT6302.h

@@ -19,8 +19,9 @@
  * USA
  */
 
-#define DISPLAY_DIGITS 12
+#define DISPLAY_DIGITS 15
-
+#include <inttypes.h>
+#include <avr/io.h>
 /* PT6302 timing constants, all in usec */
 static const uint8_t TCW = 1;     //CLKB pulse width
 static const uint8_t TDOFF = 16;  //Data processing time