From 119942f88e12f1106c081ef0eaf10470ee0305fd Mon Sep 17 00:00:00 2001
From: lucic71 <lucian.popescu187@gmail.com>
Date: Sun, 7 Jun 2020 18:40:26 +0300
Subject: [PATCH] Started LCD

---
 16x2_lcd/Makefile | 35 ++++++++++++++++++++++++++++++
 16x2_lcd/lcd.s    | 55 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 90 insertions(+)
 create mode 100644 16x2_lcd/Makefile
 create mode 100644 16x2_lcd/lcd.s

diff --git a/16x2_lcd/Makefile b/16x2_lcd/Makefile
new file mode 100644
index 0000000..ae220e5
--- /dev/null
+++ b/16x2_lcd/Makefile
@@ -0,0 +1,35 @@
+BINARY=lcd
+
+AS=avr-as
+LD=avr-ld
+OBJCOPY=avr-objcopy
+GDB=avr-gdb
+
+AVRDUDE=avrdude
+AVRDUDE_CONFIG=/etc/avrdude.conf
+
+TTY=/dev/ttyACM0
+
+ARCH=atmega328p
+
+SIMAVR=simavr
+
+build:
+	$(AS) -g -mmcu=$(ARCH) -o $(BINARY).o $(BINARY).s
+	$(LD) -o $(BINARY).elf $(BINARY).o
+	$(OBJCOPY) -O ihex -R .eeprom $(BINARY).elf $(BINARY).hex	
+
+upload:
+	$(AVRDUDE) -C $(AVRDUDE_CONFIG) -p $(ARCH) -c arduino -P $(TTY) -b 115200 -D -U flash:w:$(BINARY).hex:i
+
+sim:
+	$(SIMAVR) -m $(ARCH) $(BINARY).elf -g 
+
+debug:
+	$(GDB) $(BINARY).elf
+
+
+run: build upload
+	
+clean:
+	ls | grep $(BINARY) | grep -v *.s | xargs rm -f --
diff --git a/16x2_lcd/lcd.s b/16x2_lcd/lcd.s
new file mode 100644
index 0000000..03a363f
--- /dev/null
+++ b/16x2_lcd/lcd.s
@@ -0,0 +1,55 @@
+.equ RAMEND, 0x08FF
+
+.equ SREG, 0x3F
+.equ SPL,  0x3D
+.equ SPH,  0x3E
+
+.equ PORTD, 0x0B
+.equ DDRD,  0x0A
+
+.equ PORTB, 0x05
+.equ DDRB, 0x04
+
+.equiv PINCONFIG, 24
+
+.org 0x0000
+
+INIT_MEM:
+
+    ; Description:
+    ; -----------
+    ;
+    ;  Reset the system status in SREG, initialize the stack using SPL and 
+    ;  SPH and set output PINs on PORTB. 
+    ;
+    ; Pins used for DATA will be DIGITAL PIN 1-7 from PORTD and DIGITAL PIN 8
+    ; from PORTB.
+    ;
+    ; Pins used for REGISTER SELECT, READ/WRITE and ENABLE are DIGITAL PINS
+    ; 10, 11, respectively 12 from PORTB.
+
+    clr r16
+    out SREG, r16
+
+    ldi r16, lo8(RAMEND)
+    out SPL, r16
+
+    ldi r16, hi8(RAMEND)
+    out SPH, r16
+
+    ldi r16, 0xFE
+    out DDRD, r16
+
+    ldi r16, 0x1C
+    out DDRB, r16
+
+INIT_LCD:
+
+    ldi PINCONFIG, 0x10
+    out PORTB, PINCONFIG
+
+    ldi PINCONFIG, 0x70
+    out PORTD, PINCONFIG
+
+MAIN:
+    rjmp MAIN