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:

http://wiki.makerbot.com/v2-firmware

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'
mcu='atmega168'
Edit it so it says this:
if platform == 'ec36':
platform = 'ecv34'
default_baud = '57600'
mcu='atmega328p'

Further down the file change this:
elif (platform == 'ecv34'):
default_baud = '19200'
mcu='atmega168'
So it reads like this:
elif (platform == 'ecv34'):
default_baud = '57600'
mcu='atmega328p'
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.

 

May 29

I have these displays from an old Ship navigator i scrapped for parts.

It was a Philips Navigator, model F 505-2

I kept the displays as the three PCF8576 controller chips sat nicely behind the display glass, so i cut the PCB along the smart mechanism that holds the display glass and elastomers tight to the PCB :-)

It’s a quite curious design, the first 9 digits are standard 7-segment letters, and a bunch of symbols.

The last 18 digits are 11-segments, nor 12, 14 or 16 which seems to be the “standard” around…

Each of the last 18 characters needs 12 data bits, so writing them becomes quite a challenge, as one can only send 8 bits at a time with the I2C-bus. So writing the first character is 8 bits and you can control 8 segments, and the next byte, the first nibble is the remaining segments for the first digit etc.

So addressing the display is like this

  1. DIGIT1(8 Bits)
  2. DIGIT1(4 Bits)/DIGIT2 (4 Bits)
  3. DIGIT2(8 Bits)
  4. Etc….

Before scrapping the navigator completely, i hooked up my logic analyser to see how the chips were adressed via the I2C-bus.

A shot with all segments lit:

I wrote a simple and _ugly_ program for the Arduino to test the display, and the results can be seen here:

You can get the Arduino-program here.

May 22

Waiting for my RepRap to be finished i could just as well get to know the Arduino hardware, so i installed the programming environment from Arduino on my Mac. That went real easy and it worked in the first try. Success!

What do you start out on with a new board/compiler ? Blink an LED of course! Looking in the /File/Examples/Basics/Blink there was a test program to blink the LED on the Arduino board. Worked just fine :-)

Next i needed to try something a bit more exciting, so i dug up my trusty ‘ol PLED display (Organic LED) with a KS0066 controller (it’s HD44780 Compatible) and tried to get it work – no go, it simply wouldn’t work, so maybe it got damaged during moving my stuff – who knows.

I whipped up some wires and a bit more standard LCD display, the 162COG-BA-BC and it worked fine.

But what is fun using a standard LCD – that has to be the oldest hack in the shed – apart from the Blinking LED example.

I knew i had some NOS VFD displays kicking around somewhere, that i got from a former employer. They was controlled by SPI bus and were 1×16 character standard ASCII.

I dug them up from my Display box (yep, i actually have two boxes ONLY with displays and display-related technology, among Nixie tubes etc.)

Tried getting them to work by adjusting the example suppled with the arduino found in /File/Examples/SPI/DigitalPotControl

It simply wouldn’t work reliably, i got i to show some very dim characters and it gave me a audible whine when i changed the display contents, but almost nothing was showing on the display.

Then i caught the smell of fish! – it turns out that two capacitors on these NOS displays was leaking Electrolyte all over the PCB and main switcher, i just hadn’t seen it. Incredible for NOS electronics that has never been used (i hooked these up for a short moment when i got them years ago, but otherwise unused)

Capacitors C4 (10μF/50V) and C9 (100μF/10V) seemed to be bad – especially the C4 (SMD) it was leaking all over the switcher. I replaced both and the display sprang to life immediately.

A datasheet for the display can be found here: CU165ECPB-T2J and here: CU165ECPB_T2J_specification

You can get my test routine here – it’s very ugly but it works.

UPDATE: After looking a bit around on the net, i actually found someone else that has been playing with the same display, just on a PCB from HP. You can find documentation and a library here

May 21

Today the postman came with my Arduino Mega 1280, i ordered it on eBay link.

It’s actually destined for my RepRap that i am amidst of building right now – i have it all done, but need to make the X carriage, extruder and then i need the Motherboard, stepper controllers etc.

A fellow member at Labitat is supplying me with the boards i need :-)

Jan 01

Some people still come lurking here to see and read about my “Hack Pro” Hackintosh build.

Well i don’t have the machine any more, i sold it and bought myself a real Mac instead.

I will leave the pictures here for your viewing pleasure anyway.