try to make a-la usb-i2c-tiny over F103

F1:F103/I2C_tiny/i2c.h

@@ -0,0 +1,39 @@
+/*
+ * This file is part of the I2Ctiny project.
+ * Copyright 2024 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>
+
+typedef enum{
+	I2C_OK = 0,
+	I2C_LINEBUSY,
+	I2C_TMOUT,
+	I2C_NOADDR,
+	I2C_NACK,
+	I2C_HWPROBLEM,
+} i2c_status;
+
+void i2c_setup();
+void i2c_set_addr7(uint8_t addr);
+i2c_status i2c_7bit_send_onebyte(uint8_t data, uint8_t stop);
+i2c_status i2c_7bit_send(const uint8_t *data, int datalen);
+i2c_status i2c_7bit_receive_onebyte(uint8_t *data, uint8_t stop);
+i2c_status i2c_7bit_receive_twobytes(uint8_t *data);
+i2c_status i2c_7bit_receive(uint8_t *data, uint16_t nbytes);
+