// RGB LED Colours
// Blue indicates an error with the Thermocouple Temperature Measuring Probe Sensor
// Less than or equal to 35°C Green. Cool safe
// More than 35°C Less than or equal to 45°C Yellow. Medium Heat. This is red + some green, not total green
// More than 45°C Less than or equal to 50°C Red. Solid. Hot Danger do not touch
// More than 50°C Less than or equal to 170°C Red. Flashing. Very Hot Danger do not touch
// More than 170°C White Quick Flashing Red + Green + Blue LED : TOO HOT!!!! OVER Temperature ERROR!!!
I was powering this via the same 12 Volts going into a RAMPS 1.4.
The RAMPS 1.4 uses a PWM to adjust the temperatures of the Hot End and Heat Bed.
This caused some signal feeding back over the Power Supply to this unit causing the RGB LED not displaying the correct colours sometimes.. (false signal added to the Power Supply from the RAMPS 1.4 PWM system).
Using a Separate Power Supply stable supply appears to work better using an initial test. Displaying the colours for temperatures better.
Or watch the slow chainging back to "Green" Never really goes back to "Green"
It could be the position of "Cold Junction" of the sensor is causing
this issue i.e. not changing as quick as it should when cooling down. I
need to try to discover if the position of "Cold Junction" of the sensor
causing this issue or if it is something else.
The LED RGB: I use this to indicate that the heat bed is too hot to touch.
The LED RGB is controlled by a Arduino Nano and a Precision MAX6675 Module + K Type Thermocouple Temperature Sensor.
It could be the position of "Cold Junction" of the sensor is causing this issue i.e. not changing as quick as it should when cooling down. I need to try to discover if the position of "Cold Junction" of the sensor causing this issue or if it is something else.
The position of the "Cold Junction" being in a warm place. In my Power Supply, RAMPS box.
Also I want to want to change the Arduino Nano code a small amount so that the RGB LED shows "Blue" if there is a problem, no connection, with the thermocouple, this is quite easy change in the code.
Some information about "Cold Junction"
The hot junction is the one that's actually measuring the temperature. The cold junction is an identical thermocouple that is not exposed to heat, but kept at a known temperature. This allows absolute temperature to be measured (by essentially subtracting out the cold junction temperature
MAX6675 Cold-Junction-Compensated K-Thermocouple-to-Digital Converter (0°C to +1024°C)