gnexlab controller card ver 2.1
gnexlab controller card is a temperature monitoring and PID temperature controller for FDM 3D printers. If you have a desktop CNC machine you can easily convert your CNC to a 3D printer with this controller card. Please also check what else do you need section for the other required parts.
- Standalone No PC Connection Required
- Based on the Arduino Diecimila (Atmega 328)
- Small (84*48 pixel) Graphic LCD (Nokia 5110)
- User Friendly With Menus
- 3 button usage (UP/OK/DN)
- 2 High Power MOSFET Outputs (5A at 12V)
- 2 Relay Outputs
- 2 Thermistor Input
- 1 Thermocouple input (Max6675)
- Can Be Powered With ATX PC Power Supply
- 2 PID Computation Via On-board Micro-controller
How To Use
Thermistors are nice for general, low-quality temperature measurement. Once you get above 150C, its time to step it up. Thermocouples are a really solid way to measure high temperatures. They are accurate, reliable, and high tolerance. They also have the side benefit of being easy to mount. Simply bolt the thermocouple to the side of your thermal core and you’re ready to go.
You can select to use one thermistor for the measurement of the Heated Bed temperature. For a budget friendly version you can also use one of the thermistor for the Extruder.
In order to control your heaters you can use either power mosfets or relays and there are two of each type of circuit provided on the board. Again you will use one for powering the Extruder and one for the Heated Bed. I have designed this card with four outputs, mainly for future developments but also to provide spares just in case a circuit is accidentally damaged as the result of a wrong connection. The outputs are driven with PID computution. We have to thank the new arduino PID library. For the relays we are using “time proportioning control” because this function of the library is ideal for controlling relay outputs. I will not go into the full details here but if you want to know more on how this all works then please take a look at the Source code.
Setting the Temperatures
We have to define a Set Temperature Value for the Extruder and the Heated Bed. Please try first with 250 Degree Celsius for the Extruder and 120 Degree Celsius for the Heated Bed. The controllers main job is to set the temperatures at this values with PID. The Kp,KI and Kd parameters are hard coded to the source code. You can try different numbers if you are an expert.
The above mentioned settings are stored in the micro-controller EEPROM. So you will make the settings once. (If you are happy with them. If you are not you can change them anytime. ) You will just select the Start from the menu in regular daily use. This will activate the temperature monitoring software uploaded in the micro-controller.
The Design and Source Files
Please check the github repository for all the design files related with technology.