From d89ecc7062892649f27717aaf65f79caa2858ee8 Mon Sep 17 00:00:00 2001
From: PlexSheep <software@cscherr.de>
Date: Sat, 9 Dec 2023 11:27:55 +0100
Subject: [PATCH] printer

---
 .clangd        |  2 +-
 btn-pwm/main.c |  2 +-
 build.sh       |  6 ++++--
 include/uart.c | 35 +++++++++++++++++++++++++++++++++++
 include/uart.h | 12 ++++++++++++
 print/main.c   | 27 +++++++++++++++++++++++++++
 6 files changed, 80 insertions(+), 4 deletions(-)
 create mode 100644 include/uart.c
 create mode 100644 include/uart.h
 create mode 100644 print/main.c

diff --git a/.clangd b/.clangd
index 1d3833c..bd24b62 100644
--- a/.clangd
+++ b/.clangd
@@ -1,2 +1,2 @@
 CompileFlags:
-  Add: -I/usr/avr/include
+  Add: -I/usr/lib/avr/include
diff --git a/btn-pwm/main.c b/btn-pwm/main.c
index 4ea1b37..37f2bed 100644
--- a/btn-pwm/main.c
+++ b/btn-pwm/main.c
@@ -1,7 +1,7 @@
 /*
  * Use the timers pwm to dim a light on demand.
- */
 #define F_CPU 16000000UL
+ */
 #define __AVR_ATmega328P__
 #include <avr/interrupt.h>
 #include <avr/io.h>
diff --git a/build.sh b/build.sh
index 654e14c..39ffa23 100755
--- a/build.sh
+++ b/build.sh
@@ -12,12 +12,14 @@ else
 	avr-gcc -mmcu=atmega328p -DF_CPU=16000000L \
 		-DARDUINO=10607 -DARDUINO_AVR_NANO -DARDUINO_ARCH_AVR \
 		-I/usr/avr/include \
-		main.c -o $BUILD/main.elf
+		-I/usr/lib/avr/include \
+		../include/uart.c main.c -o $BUILD/main.elf
+
 	avr-objcopy -O ihex -R .eeprom $BUILD/main.elf $BUILD/main.hex
 
 	avr-size -A $BUILD/main.elf
 	avrdude \
-		"-C/etc/avrdude/avrdude.conf" -v -V \
+		"-C/etc/avrdude.conf" -v -V \
 		-patmega328p -carduino -P/dev/ttyUSB0 -b57600 -D \
 		-Uflash:w:$BUILD/main.hex:i
 
diff --git a/include/uart.c b/include/uart.c
new file mode 100644
index 0000000..17769e4
--- /dev/null
+++ b/include/uart.c
@@ -0,0 +1,35 @@
+#include "uart.h"
+void uart_init() {
+    /* This make stuff not work, idk
+    // set baud rate
+    UBRR0H = (MYUBRR>>8);
+    UBRR0L = MYUBRR;
+    */
+
+    /* Enable receiver and transmitter */
+    UCSR0B |= (1<<RXEN0) | (1<<TXEN0);
+    /* Set frame format: 8data, 2stop bit */
+    UCSR0C |= (1<<UCSZ01)|(3<<UCSZ00);
+
+    //Lokales interrupt enable
+    UCSR0B |= (1 << RXCIE0);
+}
+
+void uart_printc(char c) {
+        /* Wait for empty transmit buffer */
+        while ( !( UCSR0A & (1<<UDRE0)) )
+        {
+            // wartet nur
+        }
+        /* Put data into buffer, sends the data */
+        UDR0 = c;
+}
+void uart_prints(char* s) {
+    while(*s)
+        uart_printc(*s++);
+    uart_printc('\n');
+}
+char uart_getc() {
+    while (UCSR0A & (1 << RXC0));
+    return UDR0;
+}
diff --git a/include/uart.h b/include/uart.h
new file mode 100644
index 0000000..6d4e40e
--- /dev/null
+++ b/include/uart.h
@@ -0,0 +1,12 @@
+#define F_CPU 16000000UL
+#define __AVR_ATmega328P__
+#include <avr/interrupt.h>
+#include <avr/io.h>
+#include <util/delay.h>
+#pragma once
+
+void uart_init();
+void uart_prints(char* s);
+void uart_printc(char c);
+
+char uart_getc();
diff --git a/print/main.c b/print/main.c
new file mode 100644
index 0000000..a2ce855
--- /dev/null
+++ b/print/main.c
@@ -0,0 +1,27 @@
+#define F_CPU 16000000UL
+#define __AVR_ATmega328P__
+#include <avr/interrupt.h>
+#include <avr/io.h>
+#include <util/delay.h>
+#include "../include/uart.h"
+
+#define BAUD 9600
+#define MYUBRR F_CPU/16/BAUD-1
+
+
+int main (void)
+{
+    uart_init();
+    sei();
+    while (1)
+    {
+        // uart_prints("foofofofo");
+        // _delay_ms(1000);
+    }
+}
+
+ISR (USART_RX_vect) {
+    // echo the message
+    char c = UDR0;
+    uart_printc(c);
+}