diff --git a/README.md b/README.md
index 4c2359e..a89bcb4 100644
--- a/README.md
+++ b/README.md
@@ -58,10 +58,9 @@ Since there is no ICSP header on the board, you have to program the ATtiny eithe
 ### If using the makefile (Linux/Mac)
 - Make sure you have installed [avr-gcc toolchain and avrdude](http://maxembedded.com/2015/06/setting-up-avr-gcc-toolchain-on-linux-and-mac-os-x/).
 - Connect your programmer to your PC and to the ATtiny.
-- Open the makefile and change the chip if you are not using ATtiny85 and the programmer if you are not using usbasp.
 - Open a terminal.
 - Navigate to the folder with the makefile and the Arduino sketch.
-- Run "make install" to compile, burn the fuses and upload the firmware.
+- Run `DEVICE=attiny85 PROGRMR=usbasp make install` to compile, burn the fuses and upload the firmware (change DEVICE and PROGRMR accordingly).
 
 # Operating Instructions
 1. Connect the device between a power supply and a consumer.
diff --git a/software/makefile b/software/makefile
index ebcc90c..fe2aaa5 100755
--- a/software/makefile
+++ b/software/makefile
@@ -1,31 +1,41 @@
+# ===================================================================================
 # Project:  USB-Tester
 # Author:   Stefan Wagner
 # Year:     2020
 # URL:      https://github.com/wagiminator
-#
+# ===================================================================================
 # Type "make help" in the command line.
+# ===================================================================================
 
 # Input and Output File Names
-SKETCH  = USB_Tester.ino
-TARGET  = usb_tester
+SKETCH   = USB_Tester.ino
+TARGET   = usb_tester
 
-# Microcontroller Options
-DEVICE  = attiny85
-CLOCK   = 1000000
-PROGRMR = usbasp
-LFUSE   = 0x62
-HFUSE   = 0xD5
-EFUSE   = 0xFF
+# Microcontroller Settings
+DEVICE  ?= attiny85
+CLOCK    = 1000000
+LFUSE    = 0x62
+HFUSE    = 0xD5
+EFUSE    = 0xFF
 
-# Commands
-AVRDUDE = avrdude -c $(PROGRMR) -p $(DEVICE)
-COMPILE = avr-gcc -Wall -Os -flto -mmcu=$(DEVICE) -DF_CPU=$(CLOCK) -x c++ $(SKETCH)
-CLEAN   = rm -f *.lst *.obj *.cof *.list *.map *.eep.hex *.o *.s
+# Programmer Settings
+PROGRMR ?= usbasp
+
+# Toolchain
+CC       = avr-gcc
+OBJCOPY  = avr-objcopy
+OBJDUMP  = avr-objdump
+AVRSIZE  = avr-size
+AVRDUDE  = avrdude -c $(PROGRMR) -p $(DEVICE)
+CLEAN    = rm -f *.lst *.obj *.cof *.list *.map *.eep.hex *.o *.s *.d
+
+# Compiler Flags
+CFLAGS   = -Wall -Os -flto -mmcu=$(DEVICE) -DF_CPU=$(CLOCK) -x c++
 
 # Symbolic Targets
 help:
 	@echo "Use the following commands:"
-	@echo "make all       compile and build $(TARGET).bin/.hex/.asm for $(DEVICE)"
+	@echo "make all       compile and build $(TARGET).elf/.bin/.hex/.asm for $(DEVICE)"
 	@echo "make hex       compile and build $(TARGET).hex for $(DEVICE)"
 	@echo "make asm       compile and disassemble to $(TARGET).asm for $(DEVICE)"
 	@echo "make bin       compile and build $(TARGET).bin for $(DEVICE)"
@@ -34,18 +44,22 @@ help:
 	@echo "make install   compile, upload and burn fuses for $(DEVICE)"
 	@echo "make clean     remove all build files"
 
-all:	buildbin buildhex buildasm removetemp size
+all:	buildelf buildbin buildhex buildasm removetemp size
 
-bin:  buildbin removetemp size
+elf:	buildelf removetemp size
 
-hex:	buildbin buildhex removetemp size removebin
+bin:	buildelf buildbin removetemp size removeelf
 
-asm:	buildbin buildasm removetemp size removebin
+hex:	buildelf buildhex removetemp size removeelf
+
+asm:	buildelf buildasm removetemp size removeelf
+
+flash:	upload fuses
 
 install: upload fuses
 
 upload:	hex
-	@echo "Uploading to $(DEVICE) ..."
+	@echo "Uploading $(TARGET).hex to $(DEVICE) using $(PROGRMR) ..."
 	@$(AVRDUDE) -U flash:w:$(TARGET).hex:i
 
 fuses:
@@ -55,28 +69,34 @@ fuses:
 clean:
 	@echo "Cleaning all up ..."
 	@$(CLEAN)
-	@rm -f $(TARGET).bin $(TARGET).hex $(TARGET).asm
+	@rm -f $(TARGET).elf $(TARGET).bin $(TARGET).hex $(TARGET).asm
+
+buildelf:
+	@echo "Compiling $(SKETCH) for $(DEVICE) @ $(CLOCK)Hz ..."
+	@$(CC) $(CFLAGS) $(SKETCH) -o $(TARGET).elf
 
 buildbin:
-	@echo "Building $(TARGET).bin for $(DEVICE) @ $(CLOCK)Hz ..."
-	@$(COMPILE) -o $(TARGET).bin
+	@echo "Building $(TARGET).bin ..."
+	@$(OBJCOPY) -O binary -R .eeprom $(TARGET).elf $(TARGET).bin
 
 buildhex:
 	@echo "Building $(TARGET).hex ..."
-	@avr-objcopy -j .text -j .data -O ihex $(TARGET).bin $(TARGET).hex
+	@$(OBJCOPY) -j .text -j .data -O ihex $(TARGET).elf $(TARGET).hex
 
 buildasm:
 	@echo "Disassembling to $(TARGET).asm ..."
-	@avr-objdump -d $(TARGET).bin > $(TARGET).asm
+	@$(OBJDUMP) -d $(TARGET).elf > $(TARGET).asm
 
 size:
-	@echo "FLASH: $(shell avr-size -d $(TARGET).bin | awk '/[0-9]/ {print $$1 + $$2}') bytes"
-	@echo "SRAM:  $(shell avr-size -d $(TARGET).bin | awk '/[0-9]/ {print $$2 + $$3}') bytes"
+	@echo "------------------"
+	@echo "FLASH: $(shell $(AVRSIZE) -d $(TARGET).elf | awk '/[0-9]/ {print $$1 + $$2}') bytes"
+	@echo "SRAM:  $(shell $(AVRSIZE) -d $(TARGET).elf | awk '/[0-9]/ {print $$2 + $$3}') bytes"
+	@echo "------------------"
 
 removetemp:
 	@echo "Removing temporary files ..."
 	@$(CLEAN)
 
-removebin:
-	@echo "Removing $(TARGET).bin ..."
-	@rm -f $(TARGET).bin
+removeelf:
+	@echo "Removing $(TARGET).elf ..."
+	@rm -f $(TARGET).elf