Ivan Kravets / OneWire

OneWire Library lets you access 1-wire devices made by Maxim/Dallas, such as temperature sensors

Dependents:   OneWireTest mbed_blinky Affich_Lum_Moist Projetv0 ... more 

#include "mbed.h"
#include "OneWire.h"

OneWire owBus(p21);

int main()
{
    char _id[16];
    DeviceAddresses* devAddresses = owBus.getFoundDevAddresses();
    uint8_t foundNum = owBus.getFoundDevNum();
    printf("OneWire: found %d devices\r\n", foundNum);

    while(1) {
        OneWireDeviceTemperature::startConversationForAll(&owBus, OWTEMP_11_BIT);
        for (uint8_t i = 0; i < foundNum; i++) {
            OneWireDevice* owDevice = OneWireDeviceFactory::init(&owBus, (*devAddresses)[i]);
            
            if (owDevice->getFamily() != ONEWIRE_DS18B20_FAMILY)    // currently only DS18B20 supports
                continue;

            owDevice->generateId(_id);
            printf("OneWire: device #%s = %.4f*C\r\n", _id, (float) owDevice->sendGetCommand(GET_TEMPERATURE));
            delete owDevice;            
        }
        
        wait(5);
    }
 }

Diff: _headers/OneWire.h

Revision:
3:7bd102cb73e0
Parent:
2:07da4deb7135
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/_headers/OneWire.h	Tue Dec 18 12:12:21 2012 +0000
@@ -0,0 +1,73 @@
+/* Copyright (c) 2012, Ivan Kravets <me@ikravets.com>, www.ikravets.com. MIT License
+ *
+ * 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.
+ */
+ 
+#ifndef ONEWIRE_H
+#define ONEWIRE_H
+
+#include "mbed.h"
+
+#define FALSE 0
+#define TRUE 1
+
+#define ONEWIRE_DS18B20_FAMILY 0x28
+
+enum OneWireDeviceCmd {
+    SET_TEMPERATURE_RESOLUTION = 0,
+    GET_TEMPERATURE
+};
+
+typedef uint8_t DeviceAddress[8];
+typedef DeviceAddress*  DeviceAddresses;
+
+class OneWire {
+public:
+    OneWire(PinName pin);
+
+    uint8_t reset(void);
+    uint8_t readByte(void);
+    void writeByte(uint8_t val);
+    void select(uint8_t* devAddr);
+    void resetSearch(void);
+
+    uint8_t search(uint8_t* devAddr);
+    void sendGlobalCommand(uint8_t);
+    DeviceAddresses* getFoundDevAddresses();
+    uint8_t getFoundDevNum();
+
+private:
+    DigitalInOut DIO;
+    static const uint8_t dscrc_table[];
+
+    DeviceAddresses* foundDevAdresses;
+    uint8_t foundDevNum;
+
+    uint8_t lastDiscrep;
+    uint8_t doneFlag;
+    uint8_t dowcrc;
+
+    uint8_t readBit(void);
+    void writeBit(uint8_t bitval);
+
+    void skip();
+    uint8_t calcCRC(uint8_t x);
+    void findDevAddresses(void);
+};
+
+#include "OneWireDevice.h"
+
+#endif
\ No newline at end of file