Diff: ds18b20-single/DS18B20.cpp

Revision:

0:47b4bbc994df

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ds18b20-single/DS18B20.cpp	Sun May 29 16:30:05 2022 -0400
@@ -0,0 +1,163 @@
+/*	MIT License
+*
+*	Copyright (c) 2020 Lukas Gessner
+*
+*	Permission is hereby granted, free of charge, to any person obtaining a copy
+*	of this software and associated documentation files (the "Software"), to deal
+*	in the Software without restriction, including without limitation the rights
+*	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+*	copies of the Software, and to permit persons to whom the Software is
+*	furnished to do so, subject to the following conditions:
+*
+*	The above copyright notice and this permission notice shall be included in all
+*	copies or substantial portions of the Software.
+*
+*	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+*	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+*	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+*	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+*	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+*	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+*	SOFTWARE.
+*/
+
+#include "DS18B20.h"
+
+OWI::OWI(PinName pin):owi_io(pin)
+{
+	
+}
+
+void OWI::write0()
+{
+     owi_io.output();  // timeslot = 70us
+     owi_io.write(0);  // owi = 0;
+     wait_us(60);
+     owi_io.input();
+     wait_us(10);       
+}
+
+void OWI::write1()    // timeslot = 70us
+{
+     owi_io.output();
+     owi_io.write(0);  // owi = 0;
+     wait_us(6);
+     owi_io.input();
+     wait_us(64);   
+}
+
+unsigned char OWI::readBit()
+{
+     unsigned char readbit;
+     
+     owi_io.output();
+     owi_io.write(0);  // owi = 0;
+     wait_us(6);
+     owi_io.input();
+     wait_us(9);
+     readbit = owi_io.read();
+     wait_us(55);
+     
+     return readbit;
+}
+
+unsigned char OWI::detectPresence()
+{
+     core_util_critical_section_enter();
+	 
+	 unsigned char presencebit;
+     
+     owi_io.output();
+     owi_io.write(0);  // owi = 0;
+     wait_us(480);
+     owi_io.input();
+     wait_us(70);
+     presencebit = !owi_io.read();
+     wait_us(410);
+	 
+	 core_util_critical_section_exit();
+     
+     return presencebit;
+}
+
+void OWI::sendByte(unsigned char data)
+{
+     core_util_critical_section_enter();
+	 
+	 unsigned char temp;
+     unsigned char i;
+     for (i = 0; i < 8; i++)
+     {
+         temp = data & 0x01;
+         if (temp)
+         {
+              this->write1();
+         }
+         else
+         {
+              this->write0();
+         } 
+         data >>= 1;
+     }
+	 
+	 core_util_critical_section_exit();
+}
+
+unsigned char OWI::receiveByte()
+{
+     core_util_critical_section_enter();
+	 
+	 unsigned char data;
+     unsigned char i;
+     data = 0x00;
+     for (i = 0; i < 8; i++)
+     {
+         data >>= 1;
+         if (this->readBit())
+         {
+               data |= 0x80;
+         }
+     }
+	 
+	 core_util_critical_section_exit();
+     return data;
+}
+
+
+DS18B20::DS18B20(PinName pin):DS18B20_OWI(pin)
+{
+
+}
+
+float DS18B20::readTemp()
+{
+    unsigned char msb,lsb;
+    int itemp;
+    float ftemp;
+	
+	DS18B20_OWI.detectPresence();
+    DS18B20_OWI.sendByte(OWI_SKIP_ROM);
+    DS18B20_OWI.sendByte(DS18B20_START);
+	
+	#if MBED_MAJOR_VERSION >= 6
+		ThisThread::sleep_for(750ms);
+	#elif MBED_MAJOR_VERSION < 5
+		wait(0.75);
+	#else
+		ThisThread::sleep_for(750);
+	#endif
+        
+    DS18B20_OWI.detectPresence();
+    DS18B20_OWI.sendByte(OWI_SKIP_ROM);
+    DS18B20_OWI.sendByte(DS18B20_READ_SCRATCH_PAD);
+    lsb = DS18B20_OWI.receiveByte();
+    msb = DS18B20_OWI.receiveByte();
+        
+    itemp = (msb<<8)+lsb;
+    ftemp = (float)itemp / 16.0f;      
+	
+	return ftemp;
+}
+
+
+