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
diff -r 000000000000 -r b9cd1d4dcc1f OneWire.h --- /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