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: OneWire.h

Revision:
0:b9cd1d4dcc1f
Child:
2:07da4deb7135
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OneWire.h	Mon Nov 12 19:44:46 2012 +0000
@@ -0,0 +1,84 @@
+#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);
+};
+
+class OneWireDevice {
+public:
+    OneWireDevice(OneWire* ow, DeviceAddress devAddr);
+    //~OneWireDevice();
+    void generateId(char* id);
+    uint8_t getFamily();
+
+    virtual void sendSetCommand(OneWireDeviceCmd cmd, uint8_t data) {};
+    virtual float sendGetCommand(OneWireDeviceCmd cmd) {
+        return 0;
+    };
+
+protected:
+    OneWire* owBus;
+    DeviceAddress address;
+};
+
+class OneWireDeviceTemperature : public OneWireDevice {
+public:
+    OneWireDeviceTemperature(OneWire* ow, DeviceAddress address) : OneWireDevice(ow, address) {};
+    //static setResolutionForAll
+    static void startConversationForAll(OneWire* owBus, uint8_t resolution);
+};
+
+
+class OneWireDeviceFactory {
+public:
+    static OneWireDevice* init(OneWire* owBus, DeviceAddress address);
+};
+
+#include "devices/ds18b20.h"
+#endif
\ No newline at end of file