add USB settings for parameters

F1:F103/shutter/flash.h

@@ -0,0 +1,42 @@
+/*
+ * This file is part of the shutter project.
+ * Copyright 2023 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
+
+#include <stm32f1.h>
+
+#define FLASH_SIZE_REG      ((uint32_t)0x1FFFF7E0)
+#define FLASH_SIZE          *((uint16_t*)FLASH_SIZE_REG)
+
+/*
+ * struct to save user configurations
+ */
+typedef struct __attribute__((packed, aligned(4))){
+    uint16_t userconf_sz;       // "magick number"
+    uint8_t ccdactive : 1;      // ccd active (open shutter at): 0 - low, 1 - high
+    uint8_t hallactive : 1;     // hall sensor active (shutter is opened when): 0 - low, 1 - high
+    uint16_t minvoltage;        // minimal voltage on C (*100)
+    uint16_t workvoltage;       // working voltage (*100)
+} user_conf;
+
+extern user_conf the_conf;
+
+void flashstorage_init();
+int store_userconf();
+int erase_storage(int npage);
+void dump_userconf();