Week_4 - Electronics production

Assigment

Mill in-circuit programmer Fab ISP

Source the components from FabLab inventory

Solder components to the PCB

Download and set up the programming environment for programming the new programmer.

Program the new programmer with some old programmer i.e. other FabISP

Group Assignment

On this week group assignment we explore specifications of the PCB production process

There is no standardized way of producing PCBs in our fablab. Some users sub-contract more complex layouts and some of them are pickled in a friendly hackerspace or have their own PCB milling machine. In order to produce the first PCBs we came up with machines on which we could do it... and it turned out that we had quite a few:

Zmorph multitool laser, milling machine and printer in one. Unfortunately, it was problematic to force the machine to milling from MODS unfortunately there were too many differences in gcode

large milling machine which thanks to servomotors has a very high accuracy, but we left it at the very end as an option of last hope.

diy milling machine based on WOODPECKER GRBL 0.9 controller, where gcode from mods works surprisingly well (unfortunately, it turned out that the Z-axis is rotated, but we have managed to deal with this problem by changing values in the code.

Leveling surface

After selecting the milling machine, we needed grblControl software installed on a computer with windows system, a very simple software for basic operation of the machine. The first thing after installing the software and understanding the basics of operation was to level the surface which in our case was made of plywood with a 3.175 mm diamond cutter.

FAB MODULES

Fab modules, is my great unexpected love. I have to be honest that at first I was terrified and overwhelmed by the number of options that fab modules have. Fortunately when we right-click and choose programs=>open server program,

we see the beauty of possibilities of this open source tool started by Neil. The number of options is amazing but the most interesting thing is that you can add more programs to the next machines yourself.

I used G-code => mill 2d png

Then import the file in the first module select png files I found them on github
(I attach them to the documentation below)

I've set the pixel offset to 1 so that the program can interpret the rasters well and make them vectory

In the mill raster 2d module I set the diameter of the tool 0.4mm, 0.2mm cutting depth, the size of the milled surface (1 is one line 0 is full fill) I set to 0, the offset stepover I set to 0.5 to get a good surface although from my milling experience I usually rather set to 0.3.

The next setting is the path to g-code and here we have shown some imperfections in the settings of the milling machine itself. The actual speed did not match and was reduced by about 10 times. Instead of 20mm/s, the milling machines had a speed of 2mm/s so we set 100mm/sec for testing and it was a feed rate of 10mm/sec, which is quite ok, but we could do more. Due to the rotated axes we had to give 5 mm to -5 mm instead of jog height. coolant off and size in mm.

Setting-up Software

Program settings:
In the beginning, you had to set the COM milling machine,
and set the project zero point in Control panel on top right.
Due to an error in the program I also had to replace all
Z-0.2002 on Z0.2002
I did it in Atom

Oh! Breakable milling Bits

The first bit broke already on Friday on the first machine we tried, Zmorph. Unfortunately, the machine went down in an uncontrolled manner when the milling cutter stopped. Since then we decided not to use the Zmorph for this purpose and ordered several more bits.

The cutters arrived on Tuesday morning and broke like crazy no matter what settings we made. We already thought it was high time to give up and start to work on something for next week... Just that there was a crazy idea, if the bits were breaking, there was a reason for this, we ruled out the speed and sharpness of the bits, we left the length of the bit and the vibrations transmitted to it (quite a lot). We tested the broken bit . Wow, we did it! The whole plate was milled.

Milled pcb

Assembling

Soldering is a tricky stuff and you have to be careful. It is very easy to overheat the board or make a small lake of zin. It is allways importand to heat the pcb near the place we going to put zin. When i started to get whole concept of soldering, its become fun and challanging like a good old pc game.

Programing the PCB Attiny

Setting up the IDE in the mac osx Catalina
Before we start programming, we need to prepare our computer for this.
We're gonna need:

read the Fab tutorial

CrossPack

download firmware which you can find on Fabacademy tutorial page

Uzip and dlownloaded firmware files into the folder (it says in the tutorial that it is best to save it on your desktop)

Open Terminal (comand +space and write Terminal)

Go to the folder using (cd < name of folder > to go into the folder, cd.. to leave the folder, ls to list the files into the folder, to fill up the name start writing the name of folder and pres TAB )

execute lines of comand one by one

																																
$ brew install avrdude
$ brew tap osx-cross/avr
$ brew install avr-gcc
$ brew search avr
$ brew update

After updating and istalling everything with this comends we can go to the point of our work and creat .hex and .out files which are needed to program the board

																																
$ make -f makefile.make

And after that you need to connect your board thorought programmer to the computer and hit

																																	
$ make -f makefile.make program-usbtiny

Proof of working

Unfortunately, somewhere during the fight with the programmer, I forgot to document the programming and the soldering the jumper. Only what I can show to a short video that shows that the programmer works.