DS18B20 / DS1822 kabl temperaturne sonde

DS18B20/ DS1822 je najčešće korišten digitalni temperaturni senzor. Njegov izlaz je digitalni signal, koji ima karakteristike male veličine, mali hardverski troškovi, jaka sposobnost protiv smetnji i visoka preciznost. The DS18B20 digital temperature sensor is easy to wire and can be used in a variety of situations after being packaged, kao što je tip cijevi, navojni tip, vrsta magnetne adsorpcije, and stainless steel packaging type. Postoje razni modeli, uključujući LTM8877, LTM8874 i tako dalje. As a digital temperature sensor, the DS18B20 does not require any external components when measuring temperature. It can directly output the measured temperature value of 9~12 bits (including sign bit). The temperature measurement range is -55~+125℃. The measurement accuracy is ±0.5℃ in the range of -10~+85℃, and the output measurement resolution is adjustable, up to 0.0625℃. Supporting "single-wire bus" tehnologije, only one general-purpose I/O port is required to complete communication with the microcontroller. The on-site temperature is directly transmitted digitally via a "single-wire bus", which greatly improves the system's anti-interference capability.

DS18B20, DS1822 "One-line bus" digital temperature sensor Same as DS1820. DS18B20 also supports "jednolinijski autobus" interfejs, and the measurement temperature range is -55°C~+125°C, and the accuracy is ±0.5°C in the range of -10~+85°C. The accuracy of the DS1822 is ±2°C. The on-site temperature is directly transmitted digitally via the "jednolinijski autobus", which greatly improves the system's anti-interference capability. Suitable for on-site temperature measurement in harsh environments, such as environmental control, equipment or process control, temperature measurement consumer electronics, itd. The new product supports a voltage range of 3V~5.5V, making system design more flexible and convenient. And the new generation of products is cheaper and smaller. Features of DS18B20 and DS1822 DS18B20 can be programmed with a resolution of 9~12 bits and an accuracy of ±0.5°C. Optional smaller package, wider voltage range. The resolution setting and the user-set alarm temperature are stored in EEPROM and are still saved after power off. The performance of DS18B20 is the best among the new generation products! The price-performance ratio is also excellent! The DS1822 is software compatible with the DS18B20 and is a simplified version of the DS18B20. The EEPROM that stores user-defined alarm temperature and resolution parameters is omitted, and the accuracy is reduced to ±2°C. It is suitable for applications with low performance requirements and strict cost control. It is an economical product. Following the early products of the "One Line Bus", the DS1820 opens up a new concept in temperature sensor technology. DS18B20 and DS1822 provide more choices in voltage, characteristics and packaging, allowing us to build an economical temperature measurement system that suits us.

Internal structure of ds18b20 temperature probe
The internal structure of DS18B20 mainly consists of four parts:
64-bit fotolitografija ROM, temperaturni senzor, non-volatile temperature alarm trigger TH and TL, configuration register.
The pin arrangement of DS18B20 is as follows
DQ je terminal za ulaz/izlaz digitalnog signala; GND je uzemljenje napajanja; VDD je ulazni terminal eksternog napajanja (uzemljen u parazitskom načinu ožičenja).
The 64-bit serial number in the photo etched ROM is photo etched before leaving the factory. Može se smatrati serijskim kodom adrese DS18B20. Raspored 64-bitnog fotolitografskog ROM-a je: prvi 8 bits (28H) su broj vrste proizvoda, sledeći 48 bitovi su serijski broj samog DS18B20, and the last 8 bits are the previous 56-bit cyclic redundancy check code (CRC=X8 +X5+X4+1). The purpose of the photolithography ROM is to make each DS18B20 different, tako da više DS18B20 može biti povezano na jednu magistralu.
Senzor temperature u DS18B20 može dovršiti mjerenje temperature. Uzmimo 12-bitnu konverziju kao primjer: it is provided in the form of a 16-bit sign-extended two's complement reading, izraženo u obliku 0,0625°C/LSB, gdje je S bit predznaka.
Ovo su 12-bitni podaci dobiveni nakon 12-bitne konverzije, koji je pohranjen u dva 8-bitna RAM-a 18B20. Prvi 5 bits in binary are sign bits if the measured temperature is greater than 0. Ove 5 bitovi su 0. Samo pomnožite izmjerenu vrijednost sa 0.0625 da dobijete stvarnu temperaturu. Ako je temperatura manja od 0, ove 5 bitovi su 1, a izmjerenu vrijednost treba invertirati, plus 1, a zatim pomnoženo sa 0.0625 da dobijete stvarnu temperaturu.
Na primjer, digitalni izlaz od +125℃ je 07D0H, digitalni izlaz od +25,0625℃ je 0191H, digitalni izlaz od -25,0625℃ je FE6FH, a digitalni izlaz od -55℃ je FC90H.