command parser

5 files changed, 137 insertions, 3 deletions

diff --git a/src/cmd.c b/src/cmd.c
new file mode 100644
index 0000000..43b9bfc
--- /dev/null
+++ b/src/cmd.c
@@ -0,0 +1,86 @@
+/*
+ * src/cmd.c
+ * (c) 2021 Jonas Gunz <himself@jonasgunz.de>
+ * License: All rights reserved.
+ */
+
+#include "cmd.h"
+
+struct {
+	uint8_t state;
+	uint8_t cmd;
+	uint8_t argv[_CMD_MAX_ARGC];
+} cmd_state;
+
+const struct {
+	char literal;
+	void (*fkt)(uint8_t[]);
+	uint8_t argc;
+} cmd[_CMD_CNT] = {
+	{0,cmd_err,0},
+	{'p',cmd_set_pwm,2}
+};
+
+void cmd_init() {
+	cmd_state.state = 0;
+	cmd_state.cmd = 0;
+}
+
+void cmd_tick(char _c) {
+	uint8_t i;
+
+	if(_c == '\r') {
+		/* if cmd is not cmd_err and argc do not match */
+		if( cmd_state.cmd && cmd[cmd_state.cmd].argc != cmd_state.state - 1 ) {
+			/* set cmd_err to _ERR_ARGC */
+			cmd_state.cmd = 0;
+			cmd_state.argv[0] = _ERR_ARGC;
+		}
+
+		(*cmd[cmd_state.cmd].fkt)(cmd_state.argv);
+		cmd_state.state = 0;
+		cmd_state.cmd   = 0;
+		return;
+	}
+
+	if(!cmd_state.state) {
+		cmd_state.state = 1;
+		for( i=0; i<_CMD_CNT; i++ ) {
+			if( _c != cmd[i].literal )
+				continue;
+
+			cmd_state.cmd = i;
+			return;
+		}
+
+		cmd_state.cmd = 0;
+		cmd_state.argv[0] = _ERR_CMD;
+	}
+
+	/* Check, if maximum argc is reached */
+	if (cmd_state.state >= _CMD_MAX_ARGC) {
+		cmd_state.cmd = 0;
+		cmd_state.argv[0] = _ERR_ARGC;
+	}
+
+	cmd_state.argv[ (cmd_state.state++) - 1 ] = _c;
+}
+
+void cmd_set_pwm(uint8_t _argv[]) {
+	uart_putchar(_argv[0]);
+	uart_putchar(_argv[1]);
+}
+
+void cmd_err( uint8_t _argv[] ) {
+	switch(_argv[0]) {
+		case _ERR_ARGC:
+			uart_putstring("E:ARG\r\n");
+			break;
+		case _ERR_CMD:
+			uart_putstring("E:CMD\r\n");
+			break;
+		default:
+			uart_putstring("E\r\n");
+
+	}
+}
diff --git a/src/cmd.h b/src/cmd.h
new file mode 100644
index 0000000..c547f6e
--- /dev/null
+++ b/src/cmd.h
@@ -0,0 +1,28 @@
+/*
+ * src/cmd.h
+ * (c) 2021 Jonas Gunz <himself@jonasgunz.de>
+ * License: All rights reserved.
+ */
+
+#ifndef _CMD_H_
+#define _CMD_H_
+
+#include <stdint.h>
+
+#include "uart.h"
+
+#define _CMD_CNT	2
+#define _CMD_MAX_ARGC	4
+
+#define _ERR_CMD	1
+#define _ERR_ARGC	2
+
+void cmd_init();
+
+void cmd_tick(char _c);
+
+void cmd_set_pwm(uint8_t _argv[]);
+
+void cmd_err(uint8_t _argv[]);
+
+#endif
diff --git a/src/main.c b/src/main.c
index a73e7ef..131b483 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,8 +1,15 @@
+/*
+ * src/main.c
+ * (c) 2021 Jonas Gunz <himself@jonasgunz.de>
+ * License: All rights reserved.
+ */
+
 #include <avr/io.h>
 #include <avr/interrupt.h>
 #include <stdint.h>
 
 #include "uart.h"
+#include "cmd.h"
 
 uint8_t t0_ovf_cnt = 0;
 
@@ -48,16 +55,20 @@ int main(void) {
 
 	/* Uart */
 	uart_init();
+
+	cmd_init();
 	
 	/* Go! */
 	sei();
 
+	uart_putstring("START\r\n");
+
 	while(1){
 		if( uart_getchar(&c) )
 			continue;
 
 		uart_putchar(c);
-		pb0_thresh = c;
+		cmd_tick(c);
 	}
 
 	return 0;
diff --git a/src/uart.c b/src/uart.c
index 0b65e30..4431be2 100644
--- a/src/uart.c
+++ b/src/uart.c
@@ -73,3 +73,9 @@ uint8_t uart_getchar(char *_c) {
 
 	return 0;
 }
+
+void uart_putstring(char *_s) {
+	do {
+		uart_putchar(*_s);
+	} while(*(_s++));
+}
diff --git a/src/uart.h b/src/uart.h
index c709487..b2eac64 100644
--- a/src/uart.h
+++ b/src/uart.h
@@ -5,7 +5,8 @@
  */
 
 /*
- * Interrupt controlled UART
+ * Interrupt controlled UART with
+ * ringbuffers to TX and RX
  */
 
 #ifndef _UART_H_
@@ -17,7 +18,7 @@
 #include <string.h>
 
 #ifndef BAUD
-#warning BAUD "BAUD not defined. Dafaulting to 9600"
+#warning "BAUD not defined. Dafaulting to 9600"
 #define BAUD 9600
 #endif
 
@@ -33,4 +34,6 @@ uint8_t uart_putchar(char _c);
 
 uint8_t uart_getchar(char *_c);
 
+void uart_putstring(char *_s);
+
 #endif