starting CAN-GPIO, have a lot of errors

F0:F030,F042,F072/usbcan_gpio/strfunc.h

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2026 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/>.
+ */
+
+#pragma once
+
+#ifndef USBIF
+#error "Define USBIF to used interface before including this!"
+#endif
+
+#include <stdint.h>
+#include <string.h>
+#include "usb_dev.h"
+#include "usb_descr.h"
+#include "version.inc"
+
+// DEBUG/RELEASE build
+#ifdef EBUG
+#define RLSDBG "debug"
+#else
+#define RLSDBG "release"
+#endif
+
+#define REPOURL "https://github.com/eddyem/stm32samples/tree/master/F0:F030,F042,F072/usbcan_gpio " RLSDBG " build #" BUILD_NUMBER "@" BUILD_DATE "\n"
+
+// max string len to '\n' (including '\0')
+#define MAXSTRLEN    128
+
+void hexdump(int (*sendfun)(const char *s), uint8_t *arr, uint16_t len);
+const char *u2str(uint32_t val);
+const char *i2str(int32_t i);
+const char *uhex2str(uint32_t val);
+char *getnum(const char *txt, uint32_t *N);
+char *omit_spaces(const char *buf);
+char *getint(const char *txt, int32_t *I);
+
+#define printu(u)       USB_sendstr(USBIF, u2str(u))
+#define printuhex(u)    USB_sendstr(USBIF, uhex2str(u))
+