Today I did a bit of research on the MAX6675 K-thermocouple that we decided to use and I found the following resource:
Link: http://datasheets.maximintegrated.com/en/ds/MAX6675.pdf
Basically, the MAX6675 performs cold-junction compensation and digitizes the signal from a type K-thermocouple. The data is output in a 12-bit resolution, SPI-compatible, read-only format. Some key features of the MAX6675 are:
-
Direct Digital Conversion of Type -K Thermocouple Output
- Cold-junction Compensation
- Simple SPI-Compatible Serial Interface
- 12-bit, 0.25°C Resolution
- Open Thermocouple detection
The function of the thermocouple is to sense a difference in temperature between two ends of the thermocouple wires. The thermocouple’s hot junction can be read from 0°C to +1023.75°C. The cold end on the other hand can only range from -20°C to +85°C. While the temperature at the cold end fluctuates, the MAX6675 continues to accurately sense the temperature difference at the opposite end. It senses and corrects for the changes in the ambient temperature with cold-junction compensation. The device converts the ambient temperature reading into a voltage using a temperature-sensing diode. To make the actual thermocouple temperature measurement, the MAX6675 measures the voltage from the thermocouple’s output and from the sensing diode. The device’s internal circuitry passes the diode’s voltage to the conversion function stored in the ADC to calculate the thermocouple’s hot-junction temperature.
Below is the MAX6675’s block diagram:
Also, as we agreed with following the hobbybotics project, I tried to connect our block diagram that we conducted yesterday with the information provided in the webpage and I got the new following diagram:
Integrated Block Diagram
