BotHacker

I’m jumping on the heated platform bandwagon:

With 4 x 1 Ohm power resistors the output is around 36 Watts. Testing has shown that it will hold 60 C at at 70% duty cycle (178 pwm) — too hot to touch for more than an instant.

I’m driving it with my Arduino Pro Mini-based temperature controller, shown here:

This board provides two channels of thermistor based PID temperature control.  The sensor and driver circuits are borrowed from the RepRap extruder controller.  The controller will run stand-alone using pre-set temperatures, or will respond to Gen3 protocol commands over RS485.

It includes a standard PC power connector (molex) for easy RepRap use, and jumper selectable RS485 termination.

When I complete the move to a stepper driven extruder this board will control both the extruder and platform heaters.

My dabbling with Eagle has started to yield some results:

On the far left is a shield for the Seeeduino Mega that turns it into a RepRap motherboard. The Seeeduino (above the board) is a really nice Arduino Mega clone.

In the middle is a temperature controller board for an Arduino Pro Mini 328 (also shown above the board).  It will provide thermistor based PID temperature control for two heater elements, and uses RS485 for communication.  The sensor/drive circuit is borrowed from the RepRap extruder controller, and the firmware will be running my PID temperature code.

And on the right is a carrier board for four EasyDriver stepper drivers (one shown at the top).

I’ll provide more details after I finish assembly.