Hacking the HP45

Powder and inkjet printing
User avatar
dragonator
Site Admin
Posts: 482
Joined: Fri Aug 14, 2015 4:48 pm
Location: The Nethelands
Contact:

Re: Hacking the HP45

Post by dragonator »

I checked it. It should automatically create a file called image_data.txt in the same folder as either the code itself sits or where you selected the file. The "User guide" does indeed say that the bottom button exports, and I thought it did, but digging through my code it never does anything with the button right now.

Hope this helps.
User avatar
dragonator
Site Admin
Posts: 482
Joined: Fri Aug 14, 2015 4:48 pm
Location: The Nethelands
Contact:

Re: Hacking the HP45

Post by dragonator »

0805 seems a bit too big [replaces 0805 with 0402]
IMG_20170925_191822.jpg
IMG_20170925_191822.jpg (377.73 KiB) Viewed 7127 times
I got a present today. The Standalone V2.01 controller PCB's in their full gold plated glory. I will try to get these together in one piece as soon as possible. I will give more details when I am a bit further, but I hope to use these for my future projects, including Oasis. Oasis will also be redesigned and rebuilt for reasons I will give more info on later.

They look nice, but 2.01 will not be available for long. As soon as I am out of boards, I will step to V2.02. The first issue is a file issue. The 3mm holes were never drilled. This is an easy fix and doesn't warrant a redesign. The 0402 SMD components does though. I reduced the size compared to my previous board because I thought that they were too big, but kept in my head that I had 0603 on the previous board. 0402 will still work (I hope) but I do have the space and see no reason why to keep it.
User avatar
dragonator
Site Admin
Posts: 482
Joined: Fri Aug 14, 2015 4:48 pm
Location: The Nethelands
Contact:

Re: Hacking the HP45

Post by dragonator »

I learned 2 things today. 0402 sucks, and reflow soldering is magical. The next version will most definitely have 0603.

I started assembling the PCB for the V2.01 today. I have all SMD and most through hole in place. All that is left is the HP45 connector and the Teensy mount. I can not guarantee when I will do this, but I hope to be doing it within a week.
IMG_20170926_215353.jpg
IMG_20170926_215353.jpg (304.93 KiB) Viewed 7115 times
jnesselr
Posts: 19
Joined: Sat Sep 17, 2016 7:54 pm

Re: Hacking the HP45

Post by jnesselr »

It looks nice! Can you release some documentation or schematics on that controller? What do you want to change in the next version besides going to 0603? Also, what don't you like about 0402 components?
User avatar
dragonator
Site Admin
Posts: 482
Joined: Fri Aug 14, 2015 4:48 pm
Location: The Nethelands
Contact:

Re: Hacking the HP45

Post by dragonator »

Some idiot put a file size limit on this site for images, but the pdf of the schematic is attached.

It is basically the same controller as before with a few modifications. It now has 4 TLC59213 drivers, in the hope that I can now drive all nozzles at once (fingers crossed). All TLC's are connected to 2x 74HC595 shift register to save pins to allow me to use a teensy 3.2 instead of a 3.6. There was dead time between nozzle on and nozzle off that will now be filled mostly by shifting in the new data. The controller has connections for serial and SPI. There is 2 headers reserved for a future buck/boost converter to provide power to the primitives, but a solder header allows for normal 12V to the printhead. For now I will use this. There are pins left to attach to stuff like trigger signals and encoders.

I will try to write a few pieces of software to allow easy interface with this controller through Serial. I myself will be connecting it to a Raspberry pi using SPI for Oasis (the RPi will also connect to a RAMPS to control the printer itself). I hope to write universal controller software somewhere along the road, but that will be later.

The issue with 0402 is not that the parts don't work. If you need the space it is fine. But I have enough space for the 0603 components and 0402 is a disaster to handle. It is not cheaper, more robust or easier to use 0402 instead of 0603. I lost 6 resistors while populating this board and hand soldering sucks.

No real changes apart from lack of mounting holes and 0603 are planned, but if tests show issues with V2.01, I can fix these in V2.02.
Attachments
HP45 Standalone V2.01.pdf.zip
(155.22 KiB) Downloaded 472 times
jnesselr
Posts: 19
Joined: Sat Sep 17, 2016 7:54 pm

Re: Hacking the HP45

Post by jnesselr »

I see. I don't mind using either, and if we don't need the space, that's good. My goal is to eventually make a board that can handle 5 of these, so that's why I presumed I would need more room. I'm also going to have to make sure I have a really reliable current source.
User avatar
dragonator
Site Admin
Posts: 482
Joined: Fri Aug 14, 2015 4:48 pm
Location: The Nethelands
Contact:

Re: Hacking the HP45

Post by dragonator »

5 Is also my end goal, but for now I don't mind the 1. I first want to have a system that actually works. Step one is making a universally controllable system that is also useful to others. Step 2 is making upgrades for said system (variable head voltage and stuff). Step 3 is adding more heads and miniaturizing the controller further. If you want to make 5 on a single board, you can add a few shortcuts to reduce component count.

On other news, controller is starting to work. Teensy is in place, leds are soldered in the right orientation for some reason (I literally guessed both) and the first component is tested. The 78m05 is running a bit hot, but that was to be expected.
IMG_20170927_214807.jpg
IMG_20170927_214807.jpg (354.79 KiB) Viewed 7087 times
davidk
Posts: 76
Joined: Sun Mar 12, 2017 6:48 pm

Re: Hacking the HP45

Post by davidk »

Looks very nice with all components added! Teensy is a powerful device. Though I think it would have been much easier to use L6452 and Teensy.
I corrected my small mistakes into my schematic and I'll show it to you soon.I hardly can wait to see your module drawing with ink!
jnesselr
Posts: 19
Joined: Sat Sep 17, 2016 7:54 pm

Re: Hacking the HP45

Post by jnesselr »

I'm currently looking into the HV57908 because it looks like it can support high voltage outputs for up to 64 outputs at the same time. I'm trying to figure out what the difference between driving the primitive outputs and the address lines are. As best I can recall, this is a current driven application, so I don't fully understand how the higher voltage helps. Unless this is actually voltage driven and I'm just recalling badly.

I presume that with this chip, I can drive all 22 address lines, and 14 primitive lines at the same time from the same controller (within the limitations of the inkjet head). With 3 of these chips, you could drive the 180 pins needed to control 5 inkjet heads. They also chain well and work at 8Mhz to latch in data. The Vpp output voltage seems to work from 8V to 80V, so it should be fine for our use case. It can be driven by 5V, so I'm pretty happy about that.

I'm not sure about the current though, and I'm worried about that. Any thoughts on how much current is required?
Mahsa
Posts: 8
Joined: Sat May 20, 2017 11:28 am

Re: Hacking the HP45

Post by Mahsa »

@davidk
could you please explain the algorithm that can convert image to inkjet format.if its possible.
i am confused.
Post Reply