Using Thermocouple type K with AD8495
Hello together,
I am currently working on a 3D Printer and I want to use a thermocouple type K. For the connection of the thermocouple I am using a Adafruit AD8495 board and I have this config:
# First hotend configuration
temperature_control.hotend.enable true # Whether to activate this ( "hotend" ) module at all.
temperature_control.hotend.sensor ad8495
temperature_control.hotend.ad8495_pin 0.23
temperature_control.hotend.ad8495_offset 250
#temperature_control.hotend.thermistor_pin 0.23 # Pin for the thermistor to read
temperature_control.hotend.heater_pin 2.7 # Pin that controls the heater, set to nc if a readonly thermistor is being defined
#temperature_control.hotend.thermistor EPCOS100K
#temperature_control.hotend.beta 4066 # Or set the beta value
temperature_control.hotend.set_m_code 104 # M-code to set the temperature for this module
temperature_control.hotend.set_and_wait_m_code 109 # M-code to set-and-wait for this module
temperature_control.hotend.designator T # Designator letter for this module
#temperature_control.hotend.max_temp 300 # Set maximum temperature - Will prevent heating above 300 by default
#temperature_control.hotend.min_temp 0 # Set minimum temperature - Will prevent heating below if set
# Safety control is enabled by default and can be overidden here, the values show the defaults
#temperature_control.hotend.runaway_heating_timeout 900 # How long it can take to heat up, max is 2040 seconds.
#temperature_control.hotend.runaway_cooling_timeout 0 # How long it can take to cool down if temp is set lower, max is 2040 seconds
#temperature_control.hotend.runaway_range 20 # How far from the set temperature it can wander, max setting is 63°C
# PID configuration
#temperature_control.hotend.p_factor 13.7 # P ( proportional ) factor
#temperature_control.hotend.i_factor 0.097 # I ( integral ) factor
#temperature_control.hotend.d_factor 24 # D ( derivative ) factor
#temperature_control.hotend.max_pwm 64 # Max pwm, 64 is a good value if driving a 12v resistor with 24v.
The Smoothieboard shows always -115°C or -150°C depending on the polarity of the output of the AD8495 which I connect to port 0.23.
Does somebody of you ever tried a AD8495 amplifier and knows what I am doing wrong.
Thanks a lot!
kind regards
Stefan