Jun 22

Hi folks. A fellow member in Labitat, Peter assembles electronics for Makerbot, at the moment he is making:

  • Makerbot Motherboard v2.4
  • Extruder Controller v3.6
  • Stepper motor driver v3.3
  • Mech endstop v1.2


I bought a set of electronics for my RepRap Mendel that is in the making at the moment.

Peter was foresighted and fitted an Atmega328p instead of the bog standard Atmega168 that is a bit old today, this way the EC will have room for improvements which is not bad!

The standard ReplicatorG software cannot program the Atmega328p at this moment, but you can modify it by compiling the code your self, and add something in the firmware.xml – but i don’t see this as a good solution, since you won’t get updated firmware from Makerbot this way.

If you want to program your Extruder Controller fitted with a Atmea328p, follow this guide and it will work out for you:


A beginner’s mistake was writing

scons -f SConstruct.extruder
scons -f SConstruct.extruder port=/dev/SERIALDEVICE upload
It didn't work because i had not read all the instructions. It defaults to compiling
the code for the old Extruder Board 2.2 and not the Extruder Board v3.4
So running this made it work:
scons -f SConstruct.extruder platform=ecv34
scons -f SConstruct.extruder flatform=ecv34 port=/dev/SERIALDEVICE upload
This compiles the code from source to your Atmega168-fitted boards. To compile for
the Atmega328p you need to do these changes:

inside the /G3Firmware/v2/src/Extruder/ there is a SConscript file, edit this.
if platform == 'ec36':
platform = 'ecv34'
default_baud = '19200'
Edit it so it says this:
if platform == 'ec36':
platform = 'ecv34'
default_baud = '57600'

Further down the file change this:
elif (platform == 'ecv34'):
default_baud = '19200'
So it reads like this:
elif (platform == 'ecv34'):
default_baud = '57600'
With these changes you can compile for the Atmega328 ;-)

Jun 10

A member of Labitat, [Kulitorum] donated around 50 telephones to labitat since his work place scrapped them.

I took one of the phones home to reverse engineer the LCD. After about 10 minutes with the logic analyser, it was clear that it’s based on the Hitachi HD44780 or compatible controller.

Just connect the contrast pin to GND, then contrast is perfect for most projects – unfortunately the LCD is meant to be viewed from an angle, and is not good for a front panel etc. that you will view front-on.

I drew up the connections here:


Some pctures of the LCD and the adaptor i soldered up.














The phones contain some other nice parts, a DC-DC converter module some Xtal’s, Electret microphone, speaker etc.


Jun 01

Was cleaning out in the shed today, and found an old piece of kit, some kind of controller box from Evans & Sutherland with 8 encoders and 8 pcs. 8-digit LED readout

The Display units are intelligent Alphanumeric LED readouts, have to do something with them some day… Anyway, the encoders is HP QEDS-7596, enclosed optical encoders, 512 pulses per revolution. Very nice encoders, must have cost a small fortune!

Wired it to my Arduino (yep, still playing with it, hehe) and opened a serial terminal to see the position of the encoder wheel, works nicely, the resolution of these encoders are just insane.

Googled around, i wanted to show the result on my computer (i’m using a Mac) and have read about processing, but never tried it. Now i had a reason to try it out.

Downloaded it, and got it running in a few minutes, it’s just as plug and play as the arduino, very nice!

I’ll upload some pictures of the result soon.