NCT75DMR2G Application

• This project is used to verify the solution verification board design of Lichuang Mall temperature sensor/NCT75DMR2G ( product number: C94387 )
• This project is  a sample project for the Solicitation Order for Lichuang EDA open source hardware platform  solution verification module .
• NCT75DMR2G is an I²C temperature sensor produced by ON Semiconductor , operating temperature -55°C ~ 125°C, local temperature sensing -55°C ~ 125°C, supply voltage 3 V ~ 5.5 V, main features One-Shot, Output Switch , Programmable Limit, Shutdown Mode, accuracy - maximum (minimum) is ±1°C (±3°C), sensor type Digital, Local, resolution 11 b, output type I²C/SMBus
• Lead out the iic address and select it with a jumper. Up to 8 NCT75DMR2G can be connected to one bus.

The iic device address is shown in the figure below, 1001xxx. When A2, A1, and A0 are all connected to GND, it is 0x48. The NCT75 internal register address is as shown in Table 9, including temperature comparison threshold setting, low power consumption setting and the so-called one-time mode, which is low Born for power consumption applications. The temperature register address is 0x00, which is a 16-bit register. The first digit of the first 8 bits is the sign bit, 1 is negative and 0 is positive. The rest is the integer part. The first four digits of the last eight digits are the decimal part. The resolution is 0.0625℃. The last four digits are the decimal part. The bit is always 0, see the data sheet for details.

Since I am a novice, I will only use the ready-made libraries provided by Arduino to operate. I tried but failed to do the decimal part well, so I only read 8 bits and directly converted the temperature regardless of the sign bit.