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Gen6 Heatbed Daughter Board

Posted by grizgrand 
Gen6 Heatbed Daughter Board
August 13, 2011 01:32PM
Any news on this development?

Does anyone have a working heated bed with gen6 electronics?
Re: Gen6 Heatbed Daughter Board
August 13, 2011 03:34PM
I have a working heated bed but not controlled with my Gen6 board

Experimenting in 3D in New Zealand
Re: Gen6 Heatbed Daughter Board
September 15, 2011 06:39PM
I'm using Gen6 with a dumb heatbed (Prusa MK1 PCB hardwired to a 15A supply). I may look into creating an attachment through the RS485 jack. This would require minor firmware changes, though.

EDIT: A daughter board is not possible without a completely separate microcontroller. But, heatbed support could be added with some soldering effort.

Attached is a simple schematic showing the required modifications. We need one analog input pin for a heatbed thermistor, and one digital output pin for activation of a power MOSFET. Sadly, Pin 37 is the only unused Analog Input pin on Gen6, and it does not go to the RS485 port. You could still solder directly to the Atmega644P. Pin 40 will suffice for control of the MOSFET gate.

The last three pages of the PDF highlight the necessary pins and highlight access to the +5V and V+ rails. Ground is easy to find on the board. It would be easiest to go back to your power supply for V+ and GND.

Last, edit the pin mapping in your firmware to acknowledge the changes.

Edited 1 time(s). Last edit at 09/16/2011 02:01AM by jseaber.
open | download - Gen6_Heatbed_Modification.pdf (476.1 KB)
Hi Jseaber

Thanks so much for your diagram and thinking. I am toying with the idea of a seperate daughter board, but this seems so much simpler, both software and hardware wise. I have several questions.

- how would you do this, mechanically? Would you just solder thin wires to pins 37 and 40, and then run that out to a separate board? Can you think of a way to run it to some sort of jumper block? Do you think we could run it to the RS485 side of SJ1 and SJ2, and then connect the circuit directly to the RS485 port?

- Are you using the board power to drive the heated bed? Is there a limit to how much power the board can provide?

- I currently use AC to power my (dumb) heated bed; will this circuit handle AC input? If not, any suggestions?

Re: Gen6 Heatbed Daughter Board
June 17, 2013 04:24PM
Hi guys,

I'm new to 3D printing, I am just setting up my first Mendal that I brought as an unfinished kit a couple of weeks ago.
I'm running a GEN6 controller, so no integrated heat bed controller but I do have a V2.2 Extruder controller (http://www.thingiverse.com/thing:436), which is basically an Arduino with all the goodies strapped on to control heaters and read temps, control servos, drive 2 DC motors, pot, I2C, RS485, rotary encoder etc.... with all the appropriate connectors. Making this a nice little upgrade on account of it being an open source board that can be downloaded, etched / routed /purchased and populated with with the parts needed to do the job.

It would be easy enough to turn this PCB into a stand alone P.I.D. controller using the Arduino P.I.D library and tweak it in windows using the processing app but it would be even better if we could link up this (or any other Arduino 168/328 board) to a GEN6 board through the RS485 or I2C port to interface with the Marlin firmware (only one I've tried so far) to accomplish the following:-

Send bed temp to and from the GEN6 board ( so it can be monitored in windows, pronterface in my case), turn on or off the three FET's, one of course for your heat bed circuit and the other two assigned to some standard G-code commands to turn on fans etc.

The big hurdle for me is the software side, integrating it into the GEN6 board, I doubt I would figure out the comms side of things.

I just thought I'd put it out there in case anyone is interested in this idea and willing to put on their 'coding hat' and have a go!

Thanks for taking the time to read this and lets hope it kicks off and turns into a real daughter board for our GEN6 Mendals.
Re: Gen6 Heatbed Daughter Board - Easily achevable!!
June 20, 2013 08:02AM
OK peeps, tried the mod listed above and......it doesn't work!

Pin 40 on the 644 chip seems to go HIGH when the serial line is active so once you connect to your
PC, the heater will turn on. Pin 37 is the only choice for analog in and works fine.

I decided to make use of the programming header as it does nothing when your running your printer.

Physical pins on the 644:- 2,3,4 are in high impedence mode until defined in pins.h so seem to be a good choice for an add-on daughter board. This ISP header provides 5v, gnd and 3 data lines, only one more wire is needed, your analog in, which must be connected to physical pin 37 by soldering mod wire directly to the pin.

I edited the pins.h file. (Marlin v1)

Under motherboard == 5 settings change the -1 for the bed heater pin to 6 (arduino digital pin 6, atmega physical pin 2)
change the bed temp pin to 0, as is for gen 6 deluxe.

If your going to want to control a fan or turn your psu on / off just define the other 2 pins accordingly!

Remember to compare the atmega 644p data sheet against the sanguino / arduino pinouts as the dip and surface mount versions have different pinouts and pin counts. Use port numbers as reference.

Remember to pick a bed thermistor in your marlin setup, if it is set to 0 your not going to get any results for your bed temp.

Turn on the PID functionality by un comenting your defines.

Also once you have edited your pins.h (in notepad++, arduino doesnt load it for editing!!) exit and reload your arduino IDE to make use of your changes, THEN compile and upload.

Edited 1 time(s). Last edit at 06/20/2013 08:09AM by slymike.
Modded Gen6 controller running heatbed and fans
July 01, 2013 05:26AM
Just thaught I'd share some photo's of My Mendel, with it's GEN6 controller running the heat bed and cooling fans.

Its still a work in progress, when I have the time I will scrap the two PCB's in favour of an all in one daughter board.

Re: Gen6 Heatbed Daughter Board - Easily achevable!!
July 22, 2013 10:22AM

I'll wait impatiently the final board!
Re: Gen6 Heatbed Daughter Board
July 22, 2013 02:15PM

It's nice that someones interested, I thought I was the only one with a Gen6 board on this forum. lol.
I've only been into 3D printing for about 2 months and feel I may be a little behind the times as I picked up an unfinished Mendel and a box of spares and built it with what I found in the box.


I designed a second PCB that controls the cooling fan and has connections for motor cooling fans, with speed adjustment, plus a few more connectors for 12v accessories.

Both fan circuits have speed adjustment using LM317's and a pot. Each has a toggle switch, the one on the print cooling circuit selects between (a) the selected speed or (b) full on. The other works in the same way but depending on whether a resistor (SMT 0R) if fitted or not, selects full on or off.

Its got power distribution, 3 fuses, one for the controller power circuit, 1 for the fan circuit and 1 for the heated bed.

XBOX PSU power switch and screw down connections.

Also some LED's for power on, heat bed on, fans on and one spare which is connected to the last remaining I/O pin on the Atmega chip, which I will probably find a use for at some point.

Which bring me on to the aux connector, wired to the above mentioned I/O. this can used in either direction and is connected to an NPN transistor which can sink 1 amp.

This board DOES NOT have a FET on board to control the heat bed as I'm quite happy with the little board that is strapped onto my Gen6.
The reason I didn't add it into this PCB was that the heatbed thermistor circuit must be wired directly to the chip on the Gen6 and i wanted to make a PCB that I could (a) disconnect quickly and (b) tidy up my wiring.

I however probably will design an all in one PCB once my Mendel is out of its prototype phase, Im just trying to get everything working properly at the moment and do some nice prints (I'm nearly there, first decent fan mount was completed at 1am this morning... Yawn.)

Also in a day or two I will upload a modded version of Marlin v1 with heatbed and fan control for Gen6 PCB's for those who can't get there heads around the code side of things, I'm just lucky I've been playing with an Arduino for the past year ;-)

A RAR file is attached containing the dodgy looking schematic and PCB Layout in Cadsoft Eagle format.
open | download - slymikes power and fan pcb v1.rar (98.2 KB)
Re: Gen6 Heatbed Daughter Board
July 22, 2013 05:09PM
slymike Wrote:
> It's nice that someones interested, I thought I
> was the only one with a Gen6 board on this forum.
> lol.

No, you're not alone :-)

Thanks for sharing.
Re: Modded Gen6 controller running heatbed and fans
July 28, 2013 05:10AM
I'd be very interested in you final solution for this. Looks great. Never thought of using the ISP header smiling smiley. Still learning everyday....
Re: Gen6 Heatbed Daughter Board
July 29, 2013 08:17AM
Here are some links to the modified Marlin v1 firmware for the GEN6 Daughted Board.




Re: Gen6 Heatbed Daughter Board
August 12, 2013 07:58AM
Hey guys,

I've recently finished adding bed and fan support to my Gen 6. I just updated the Gen 6 wiki page with details on how to get to the pins.

You can see my solution below. If theres interest I would post schematiccs.

open | download - DSC_0460.jpg (479.2 KB)
Re: Gen6 Heatbed Daughter Board
September 14, 2013 09:01AM
You are not alone with the old Gen6 board! smiling smiley I'm running one for a long time now!
This is great work!

Re: Gen6 Heatbed Daughter Board
September 17, 2013 08:42AM
smiling smiley

A wise man once told me "Never trust a man who doesn't own a shed!"
Gen 6 daughter board
Mendel PCB heatbed
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