One-Wire Temperature Sensor - DS18B20
Reference Information
- Techinical Spec: Temperature range: -55°C to +125°C - Accuracy: ±0.5°C( -10°C to +85°C)
- Connector Type: Base Shield V1.3 - Grove compatible - http://seeedstudio.com/depot/base-shield-v13-p-1378.html
- Code Source: http://playground.arduino.cc/Learning/OneWire
Temperature Sensor - DS18B20 - (Waterproof)
MyNbios Code - Example
In order to run this code you should copy the following code into the area delimited by the MY_BIOS CUSTOM CODE banners in the Hello_World_xxx.ino example.
#include <OneWire.h> OneWire ds(3); // Arduino PIN_3 void Nearbus::MyNbios_0( byte portId, ULONG setValue, ULONG* pRetValue, byte vmcuMethod, PRT_CNTRL_STRCT* pPortControlStruct ) { byte i; byte present = 0; byte type_s; byte data[12]; byte addr[8]; float celsius, fahrenheit; for (i=0 ; i < 20 ; i++) { if ( ds.search(addr)) { break; } ds.reset_search(); delay(250); } if (i == 20 ) { *pRetValue = 0; return; } if(OneWire::crc8(addr, 7) != addr[7]) { *pRetValue = 0; return; } // the first ROM byte indicates which chip switch (addr[0]) { case 0x10: type_s = 1; break; case 0x28: type_s = 0; break; case 0x22: type_s = 0; break; default: *pRetValue = 0; return; } ds.reset(); ds.select(addr); ds.write(0x44, 1); // start conversion, with parasite power on at the end delay(1000); // maybe 750ms is enough, maybe not present = ds.reset(); ds.select(addr); ds.write(0xBE); // Read Scratchpad for ( i = 0; i < 9; i++) { // we need 9 bytes data[i] = ds.read(); } int16_t raw = (data[1] << 8) | data[0]; if (type_s) { raw = raw << 3; // 9 bit resolution default if (data[7] == 0x10) { // "count remain" gives full 12 bit resolution raw = (raw & 0xFFF0) + 12 - data[6]; } } else { byte cfg = (data[4] & 0x60); // at lower res, the low bits are undefined, so let's zero them if (cfg == 0x00) raw = raw & ~7; // 9 bit resolution, 93.75 ms else if (cfg == 0x20) raw = raw & ~3; // 10 bit res, 187.5 ms else if (cfg == 0x40) raw = raw & ~1; // 11 bit res, 375 ms // default is 12 bit resolution, 750 ms conversion time } celsius = (float)raw / 16.0; fahrenheit = celsius * 1.8 + 32.0; if ( !setValue ) { // NearAPI: [value=1] => Fahrenheit - [value=0] => Celsius *pRetValue = (ULONG) (celsius * 100); } else { *pRetValue = (ULONG) (fahrenheit * 100); } }