MCP9902 Remote Temperature Sensor
Created: Jul 13, 2016
No description available.
Temperature data is relevant in industrial applications and processes. It helps in monitoring industrial operations and implementing control processes to improve the system and provide ease and safety to workers. Not only to industrial level applications that this has become significant but also even to hobbyist. Nowadays, there are many available sensors and devices that make us able to do temperature measurement and incorporate them to personal applications.
This circuit is a temperature sensor board based on the MCP9902 device. The device is a high-accuracy, low-cost temperature sensor. It has two-channel SMBus temperature sensor with programmable address capability. It also features Resistance Error Correction (REC) capability that can be demonstrated through potentiometer R7 used vary the resistance. When REC is enabled, the temperature will not change as the resistances are increased. When REC is disabled, a significant temperature error will occur; every ohm of resistances increases the temperature error approximately 0.6°/Ω. To utilize the circuit in measuring remote places or devices, the on board transistor is removed and a diode with cable assembly or an external CPU/GPU diode can be connected to connector J1. The board implements the MCP2221 protocol converter to ensure communication from USB to I2C. The 3.3V voltage supply is delivered to the circuit from the +5V USB rail by an on-board LDO. Status LEDs are also included to provide information about board’s power, /alert and /therm signals. Temperature readings can be viewed through the Chip Manager application software where users are allowed to view and modify the registers.
This board provides the means to demonstrate all of the MCP9902 features. Beside the REC capability, the device also has a beta compensation and automatic diode-type detection feature, combined to provide a robust solution for complex environmental monitoring applications. Typical application may include general-purpose temperature sensing, industrial freezers and refrigerators, food processing, base stations and remote radio units.