add F103 PL2303 with ring buffer

F1:F103/PL2303_ringbuffer/main.c

@@ -0,0 +1,83 @@
+/*
+ * This file is part of the pl2303 project.
+ * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hardware.h"
+#include "proto.h"
+#include "usart.h"
+#include "usb.h"
+
+#define USBBUFSZ    127
+
+volatile uint32_t Tms = 0;
+
+void sys_tick_handler(void){
+    ++Tms;
+}
+
+// usb getline
+char *get_USB(){
+    static char tmpbuf[USBBUFSZ+1], *curptr = tmpbuf;
+    static int rest = USBBUFSZ;
+    uint8_t x = USB_receive(curptr);
+    if(!x) return NULL;
+    curptr[x] = 0;
+    if(curptr[x-1] == '\n'){
+        curptr = tmpbuf;
+        rest = USBBUFSZ;
+        return tmpbuf;
+    }
+    curptr += x; rest -= x;
+    if(rest <= 0){ // buffer overflow
+        curptr = tmpbuf;
+        rest = USBBUFSZ;
+        USEND("USB buffer overflow\n");
+    }
+    return NULL;
+}
+
+int main(void){
+    StartHSE();
+    hw_setup();
+    SysTick_Config(72000);
+    hw_setup();
+    usart_setup();
+    USB_setup();
+
+    uint32_t ctr = Tms;
+    while(1){
+        if(Tms - ctr > 499){
+            //USEND("ping\n");
+            ctr = Tms;
+            LED_blink(LED0);
+            usart_transmit();
+        }
+        char *txt = NULL;
+        usb_proc();
+        if((txt = get_USB())){
+            USEND("Got USB data\n");
+            const char *ans = parse_cmd(txt);
+            if(ans) USB_send(ans);
+        }
+        if(usartrx()){
+            if(usart_getline(&txt)){
+                const char *ans = parse_cmd(txt);
+                if(ans) USEND(ans);
+            }
+        }
+    }
+}