Digital emulator of Thermocouple (K,J,N,E,T,S,R,B) with mcu ESP8266

The board was built to generate two voltages (mV) isolated from each other and from the ground by emulating that produced by a thermocouple already compnsata by a cold junction of zero degrees. Some parameters are sent via Wifi: TC type (J, K ..), TC temperature and no. Output channel on which to generate the voltage. The board is also designed for the generation of a linear ramp in a fixed interval between two set temperatures and with an incremental step of one degree. It is the 12bits mcp4821 DAC that generates the simulated output voltage. This DAC is suitably controlled by the Esp8266 mcu with the SPI bus, and produces the appropriate voltage value through the numerical values ​​of tables contained in RAM as a function of the temperature and type of TC. A resistive divider with attenuation 100 reduces the DAC voltage to the equivalent values ​​of the TCs. This DAC has a compensated internal reference voltage avoiding numerical conversion errors. The tolerances of the resistances are calculated during the construction of the board..