DS18B20 / Cable de sonda de temperatura DS1822

DS18B20/ DS1822 is a commonly used digital temperature sensor. Its output is a digital signal, which has the characteristics of small size, Despestament de maquinari baix, strong anti-interference ability and high precision. The DS18B20 digital temperature sensor is easy to wire and can be used in a variety of situations after being packaged, such as pipe type, Tipus roscat, Tipus d’adsorció d’imants, and stainless steel packaging type. There are various models, inclòs LTM8877, LTM8874, etc.. 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" technology, 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 "Bus de línia" interface, 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 "Bus de línia", 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, etc. 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-Fotolitografia de bits rom, Sensor de temperatura, non-volatile temperature alarm trigger TH and TL, configuration register.
The pin arrangement of DS18B20 is as follows
DQ és el terminal d’entrada/sortida del senyal digital; GND és el terreny elèctric; VDD is the external power supply input terminal (basat en el mode paràsit de cablejat de potència).
The 64-bit serial number in the photo etched ROM is photo etched before leaving the factory. Es pot considerar com el codi de sèrie de l'adreça del DS18B20. La disposició de la fotolitografia de 64 bits ROM és: el primer 8 bites (28H) són el número de tipus de producte, the next 48 Els bits són el número de sèrie del propi 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, de manera que es poden connectar múltiples ds18b20s a un autobús.
El sensor de temperatura de DS18B20 pot completar la mesura de la temperatura. Preneu la conversió de 12 bits com a exemple: it is provided in the form of a 16-bit sign-extended two's complement reading, expressat en forma de 0,0625 ° C/LSB, on s és el bit de signe.
Es tracta de les dades de 12 bits obtingudes després de la conversió de 12 bits, que s’emmagatzema en dos rams de 8 bits de 18b20. El primer 5 bits in binary are sign bits if the measured temperature is greater than 0. These 5 Els bits ho són 0. Només heu de multiplicar el valor mesurat per 0.0625 Per obtenir la temperatura real. Si la temperatura és inferior a 0, aquests 5 Els bits ho són 1, i cal invertir el valor mesurat, més 1, i després es va multiplicar per 0.0625 Per obtenir la temperatura real.
Per exemple, La sortida digital de +125 ℃ és 07d0h, La sortida digital de +25.0625 ℃ és 0191H, La sortida digital de -25.0625 ℃ és FE6FH, i la sortida digital de -55 ℃ és FC90H.