From e64880f66c751d6f1c5bb18cfad0f1c2eb167b12 Mon Sep 17 00:00:00 2001
From: Leon Krieg <info@madcow.dev>
Date: Tue, 27 Aug 2024 15:09:06 +0200
Subject: [PATCH] Move parser to separate module and add USART_IsDataAvailable

---
 src/main.c   | 54 +++++-----------------------------------------------
 src/parser.c | 44 ++++++++++++++++++++++++++++++++++++++++++
 src/parser.h |  6 ++++++
 src/serial.c |  9 +++++++--
 src/serial.h |  3 +++
 5 files changed, 65 insertions(+), 51 deletions(-)
 create mode 100644 src/parser.c
 create mode 100644 src/parser.h

diff --git a/src/main.c b/src/main.c
index adc6b5e..8ba3060 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,52 +1,6 @@
 #include "common.h"
 #include "serial.h"
-
-#include <avr/interrupt.h>
-
-
-// # Serial Input Data Flow
-//   USART INTERRUPT -> RING BUFFER -> COMMAND PARSER STATE MACHINE
-//
-// # Supported Commands
-//   (Optional decimal point for numbers)
-//   - START
-//   - RESET
-//   - STOP
-//   - SET TEMP 20
-//   - SET DEWP 60.0
-
-static int state;
-
-void parse(char ch)
-{
-	switch (state) {
-	case 0:
-		if (ch == 't')
-			state = 1;
-		break;
-	case 1:
-		if (ch == 'e')
-			state = 2;
-		else
-			state = 0;
-	case 2:
-		if (ch == 's')
-			state = 3;
-		else
-			state = 0;
-	case 3:
-		if (ch == 't')
-			state = 4;
-		else
-			state = 0;
-	case 4:
-		if (ch == '\n') {
-			USART_Printf("[CORE] Parsed 'test'!\r\n");
-			state = 0;
-		} else
-			state = 0;
-	}
-}
+#include "parser.h"
 
 int main(void)
 {
@@ -58,8 +12,10 @@ int main(void)
 	for (i = 1;; i++) {
 		if (i >= 99999) i = 1;
 
-		while ((ch = USART_GetChar())) {
-			parse(ch);
+		if (USART_IsDataAvailable()) {
+			while ((ch = USART_GetChar())) {
+				CMD_Parse(ch);
+			}
 		}
 
 		USART_Printf("[CORE] Fetching sensors #%05lu...\r\n", i);
diff --git a/src/parser.c b/src/parser.c
new file mode 100644
index 0000000..736956e
--- /dev/null
+++ b/src/parser.c
@@ -0,0 +1,44 @@
+#include "common.h"
+#include "serial.h"
+#include "parser.h"
+
+// # Supported Commands
+//   (Optional decimal point for numbers)
+//   - START
+//   - RESET
+//   - STOP
+//   - SET TEMP 20
+//   - SET DEWP 60.0
+
+static int state;
+
+void CMD_Parse(char ch)
+{
+	switch (state) {
+	case 0:
+		if (ch == 't')
+			state = 1;
+		break;
+	case 1:
+		if (ch == 'e')
+			state = 2;
+		else
+			state = 0;
+	case 2:
+		if (ch == 's')
+			state = 3;
+		else
+			state = 0;
+	case 3:
+		if (ch == 't')
+			state = 4;
+		else
+			state = 0;
+	case 4:
+		if (ch == '\n') {
+			USART_Printf("[CORE] Parsed 'test'!\r\n");
+			state = 0;
+		} else
+			state = 0;
+	}
+}
diff --git a/src/parser.h b/src/parser.h
new file mode 100644
index 0000000..ee28894
--- /dev/null
+++ b/src/parser.h
@@ -0,0 +1,6 @@
+#ifndef MAD_PARSER_H
+#define MAD_PARSER_H
+
+void CMD_Parse(char ch);
+
+#endif // MAD_PARSER_H
diff --git a/src/serial.c b/src/serial.c
index 0a9ec7e..00214c5 100644
--- a/src/serial.c
+++ b/src/serial.c
@@ -1,8 +1,8 @@
-#include "serial.h"
 #include "common.h"
+#include "serial.h"
 
-#include <stdio.h>
 #include <stdarg.h>
+#include <stdio.h>
 #include <avr/io.h>
 #include <avr/interrupt.h>
 
@@ -66,6 +66,11 @@ void USART_Printf(const char *fmt, ...)
 	}
 }
 
+bool USART_IsDataAvailable(void)
+{
+	return rxhead != rxtail;
+}
+
 // Interrupt Handler
 ISR(USART_RXC_vect)
 {
diff --git a/src/serial.h b/src/serial.h
index abd7145..44138ed 100644
--- a/src/serial.h
+++ b/src/serial.h
@@ -1,9 +1,12 @@
 #ifndef MAD_SERIAL_H
 #define MAD_SERIAL_H
 
+#include <stdbool.h>
+
 void USART_Init(void);
 char USART_GetChar(void);
 void USART_PutChar(const char ch);
 void USART_Printf(const char *fmt, ...);
+bool USART_IsDataAvailable(void);
 
 #endif // MAD_SERIAL_H