feat: onewire and ds18b20 driver

lib/ds18b20/ds18b20.c

@@ -0,0 +1,18 @@
+#include "ds18b20.h"
+#include "onewire.h"
+
+void DS18B20_startConvert(void) {
+    OneWire_init();
+    OneWire_writeByte(DS18B20_SKIP_ROM);
+    OneWire_writeByte(DS18B20_CONVERT_TEMP);
+}
+
+int DS18B20_readTemperature(void) {
+    OneWire_init();
+    OneWire_writeByte(DS18B20_SKIP_ROM);
+    OneWire_writeByte(DS18B20_READ_SCRATCHPAD);
+    uchar T_LSB = OneWire_readByte();
+    uchar T_MSB = OneWire_readByte();
+    int temp = T_MSB << 8 | T_LSB;
+    return temp;
+}

lib/ds18b20/ds18b20.h

@@ -0,0 +1,20 @@
+#ifndef __TEMP_H
+#define __TEMP_H
+
+#ifndef uchar
+#define uchar unsigned char
+#endif
+
+#ifndef uint
+#define uint unsigned int
+#endif
+
+#define DS18B20_SKIP_ROM            0xCC
+#define DS18B20_CONVERT_TEMP        0x44
+#define DS18B20_READ_SCRATCHPAD     0xBE
+
+void DS18B20_startConvert(void);
+
+int DS18B20_readTemperature(void);
+
+#endif