Electronics Production


We can make Almost Anything

Weekly Task

Group assignment:

   Characterize the specificatons of PCB production process.

Individual assignment:
  •  Make an incircuit programmer by milling the PCB
  •  Optionally, try other ways.

What is PCB

As I read on Wikipedia.PCB(printed circuit board) is mechanically supported and electrically connects electronic components or electrical components using conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Components are generally soldered onto the PCB to both electrically connect and mechanically fasten them to it.

Roland monoFab SRM-20

here we started group assignment.

Introduction of Machine
We have two PCB Milling Machine one is Modella MDX-20 and second one is Roland monoFab SRM-20.but study on Roland monoFab SRM-20 and used it for making my fabTinyisp board.as I saw on Roland site.SRM-20 is Roland's latest generation 3D desktop milling machine, incorporating innovative subtractive rapid prototyping (SRP) features to deliver accuracy, smooth finishes and efficiency in a compact format.



Specifications of SRM-20

Model SRM-20
Cuttable Material Modelling Wax, Chemical Wood, Foam, Acrylic, Poly acetate, ABS, PC board
X, Y, and Z Operation Strokes 203.2 (X) x 152.4 (Y) x 60.5 (Z) mm
Workpiece table size 232.2 (X) x 156.6 (Y) mm
Distance From Collet Tip to Table Max, 130.75mm (5.15 in)
Loadable Workpiece Weight 2 kg (4.4 lb)
Control Command Sets RML-1, NC code
External Dimensions 451.0 (W) x 426.6 (D) x 426.2 (H) mm
Weight 19.6 kg (43.2 lb)
Group Assignment - Line Test

1.I downloaded .png file on fabacademy schedule.



2.I did same process.



3.I used Fab Modules for making .rml file.





4.Cut design.



Ready.



This Specification reads on Roland SRM-20 Module page.

FabISP fabrication

Neil introduced 4-5 types programmer to us. From which I choose Brian because I'm novice for this assignment and his document is very good for making programmer. Below image is the brian schematic and board image:





Setting of SRM-20 Machine
Process : As I told before I used roland monoFab SRM-20 milling machine for making my FabISP.
Bed area - 200*150mm

Step 1.- Bed level and origin set
First, I stick the board using double sided tape on bed.I set the Origin by clicking X,Y and Z button. Now I check the X/Y placement and set it according to my PCB board placement. After, that I check the gravity of end mill of 1/32 which is create traces on the PCB.



Step 2.- End mill
For traces on the PCB I used 1/64 end mill which is recommended on this machine cause. By this end mill traces were good. For outline cutting I used 1/32 end mill which is cut the PCB according to the outline.



Step 3.- End mill fix in Machine



Step 3.- Set the Gravity
Then I checked gravity. slowly moves the windmill header in down direction, then loose the end mill and touch to bed by gravity and then tight it.I gave print. Now selects the 1/32 (mill cutout board).



Fab Module


I downloaded .PNG file from Brian downloaded .png files looks like this.





1.I Go to Fab Module on google.then clicked on input device and chose .png.when Brower opned then I choosed downloaded PCB trace file.then converted into .rml file .and also chose PCB traces (1/64). Always check the real size and resolution of your board.
  • Machine - SRM-20
  • x0(mm) - 0
  • y0(mm) - 0
  • z0(mm) - 0 These x0,y0,z0 are for setting up an origin save in V-Panel
  • zjog - 12
  • Speed - 4 or 3 mm/s for new end mills
  • x/y/x home is the parking position after finishing the cut after selected machine (SRM-20),gave speed and height and clicked on Calculate and then saved.after saved, downloaded .rml file in your Computer/Laptop.



    2.Here,I did same process.just change PCB outline (1/32) and downloaded .rml file.



    Clicked “Cut” on the control panel. A new window will appear where you will select your traces cutting file, now click Output and the machine should start.



    Cut my PCB on Machine.



    After milling my board. I used vaccum cleaner/brush to clean the board.



    The finished PCB look like this.My board is ready for soldering.



    Soldering



    Before starting soldering.I collected components in our fab Inventory.I collect components which is required brian board i.e. following:
  • 1x ATtiny45 or ATtiny85
  • 2x 1kΩ resistors
  • 2x 499Ω resistors
  • 2x 49Ω resistors
  • 2x 3.3v zener diodes
  • 1x red LED
  • 1x green LED
  • 1x 100nF capacitor
  • 1x 2x3 pin header


  • this image shows what components I used.



    I dont have any experience about soldering.this was new for me.so,for practices I took wasted PCB.then I did many components solder and desolder from wasted PCB.also I have used hot air gun for removing components from board with proper temperature.I did mistakes many time,but I learned soldering properly.

    Then I made new board. After stuffing the components I checked it with the help of multimeter whether the Resister are showing the right values and there is connectivity or not.



    After completed my soldering.I checked the continuity.



    I checked the connection on my laptop.I saw Power LED was blinked.



    fabISP Programming

    First I going to program on Windows machine, for program on windows 10. I used git bash for command and controlling the board. I follow the two tutorial like Brian then for process. I followed USBasp on Windows for detecting the USBasp on windows I also try driver to install and I got it from this site USBasp on Windows but is not detecting after completing the installation.

    For programming on windows I install 4 different software like a. Make.exe 2. avrdude 3. avr8-gnu-toolchain-installer-3.5.4.91-win32.any.x86.exe 4. zadig and download firmware_45 to store all data.all files save in programs files.



    Windows where to locate all of the tools you've just installed when you type their names on the command line. Go to the Start menu and open the Control Panel, then go to System. From the left pane, choose "Advanced System Settings". Under the Advanced tab, click the "Environment Variables" button.



    Under User variables, select "Path" and click the Edit button. If you don't already have a variable called "Path", click the New button to create it, enter "Path" without the name, and fill out the value as described below.

  • C:\Program Files\avr8-gnu-toolchain\bin
  • C:\Program Files (x86)\GnuWin32\bin
  • C:\Program Files\avrdude
  • After this steps I Installed Drivers for my Programmer.I downloaded Zadig.then Plug in my programmer, and select the "USBasp" device in the list.The driver you want to install (to the right of the green arrow) is either libusb-win32 or libusb0. Click the "Install Driver" button.



    Everything is now installed.this is the important part for ISP pin to attached with the programmer board as pin1=MISO; pin2=VCC/Vpprog; pin3=SCK; pin4=MOSI; pin5=RST; pin6=GND; follow this pin out and connect with USBasp and programmer.After that I used git bash for control the command of board.I checked that it all works.Go to the start menu and search for "Git Bash" and start it.

    I used three cammands for Checked to make sure that the commands I installed work ok or not.

  • Type make -v and press enter
  • Type avr-gcc --version and press enter
  • I Connected programmer to a USB port and type: avrdude -c usbtiny -p t45 and press enter.


  • I Downloaded the firmware source code from Brian and extract the zip file.Opened terminal program and cd into the source code directory.

    Run make. This make cammand build the hex file that will get programmed onto the ATtiny45. When the command completes.In this folder I opened Make filewith Notepadd++ and change the name USBTiny ti usbasp.



    then I run make flash cammand.when I runed this cammand i got Error,beacuse of my not well soldering.then i did reapeat soldering.again I type this cammand its works properly.



    After I run make fuses cammand.after completed this cammand I remove all connectors and checked fabISP on my laptop.I go to Devices and checked my USB was deteted or not.when I checked my board was worked.



    then last cammand I used make rstdisbl



    Finally its going to programmed.Final programming and Detection of USBasp by PC: Here I complete the programming process and check the board after removing the bridge line.



    Explored

    MODS for PCB

    We have arranged guest lecture of Previous fab academy student Mr.Rohan Rege on MODS.
    MODS is the new FABMODULES it more capable and works by connecting nodes to develop each process.In our case we are going to use a precompiled program and add a module to save automatically in our computer instead of connecting directly to the machine.

    1.I Opened Mods in browser recommended firefox/chrome.

    2.Then Right click anywhere and select PROGRAMS -- select OPEN SERVER PROGRAM




    3.Selected ROLAND > MILL > SMR20(choose the machine you will use)



    We need to add another module to make it save the file automatically. So we need to look for the program/component that outputs the file.

    4.Right clicked anywhere in the white space and select MODULE > OPEN SERVER MODULE > SAVE FILE . Connect the elements by clicking on OUTPUT of RolandSrm-20milling machine and clicking again in INPUT of save file module to make the connection/ wiring between them.



    5.Open your traces image file.Go to READ PNG MODULE SELECT- PNG FILE - .selected traces image.



    6.SET PCB Default module click in MILL TRACES.



    7.Mill Raster 2D module click in Calculate

    8.Done.The file will be saved automatically into your download folder.

    Flexible fabISP

    1.I tried to making flexible fabISP on Vinyl Cutter. First I took downloaded .png file from Brian. then open terminal I used this cammands.
  • Sudo Fab
  • - Enter password
    From input format select (image).png
    Selected Roland Vinylcutter (.camm)
    make_png_camm
    then I loaded .png file and sended to Vinyl.



    2.I did same process.



    3.I cuted on Vinyl.



    4.I cut unwanted parts using x-acto knife.



    5.my flexible FabISP is Ready.













    Learning Outcomes

    In this assignment I learned about PCB,Soldering, milling and programming. We learn monoFab SRM-20 PCB milling machine and process of milling in a group. Soldering is a skill work and I have to improve my skill.Also I learnt how to used fab Modules on browser.I also used MODS.and tried to making Flexible FabISP on vinyl.so learnt more things in this assignment.