Fablogo

Week 4 - Electronics production

Learning Outcomes :

PCB Fabrication:

The assignment for this week was to Fabricate the FabISP(In-system programming). The FabISP is an in-system programmer for AVR microcontrollers that allows us to program the microcontrollers (brains) on other boards using an usb cable and the 6 pin IDC cable. It will be used several times along the semester so it is an important assignment. I divided it into several little projects:

Manufacturing Procedure:

I made the ISP from a copper plate using Roland monoFab SRM-20 milling machine

  1. Download Board Files; hello.ISP.44.traces.png and hello.ISP.44.interior.png
  2. The gcode (.rml) files for the machine was generated using Fabmodules
  3. On Fabmodules Click in Input Format
  4. Choose Image(.png) and Upload Desired Board Image
  5. Click in Output Format and choose the machine to be used (This case Roland Mill .rml)
  6. Machine Settings: in output machine choose SRM-20; Xmin 0; Ymin 0;
  7. Click in Process and choose Mill bit to be used; 1/64 = .0.4mm (used to engrave the traces); 1/32 = 0.8mm (used to cut the board)
  8. Change offset to 4(this will give the amount of times the bit passes in your board and give a thickness to the traces
  9. Click on Calculate
  10. Save
  11. Now mount the desired bit into the machine and set the milling origin using the Vpanel Software; start with the XY axes then the Z(when the z is lowered to its maximum loosen the bit and let it slide till it touches the copper)
  12. Click Cut; Delete all Files; Add Desired Cutting File
  13. Start Cutting
  14. Repeat process for the outer cut
    15.

Milling Station Roland SRM-20

Software to control Roland (VPanel) Where origin of XYZ axes are controlled and where the files to cut are uploaded.

Milled Board

Cleaned with Metal ball scourares and after that water and soup

Download the milling files here:

Soldering

Before we start soldering there are some important tips about the soldering station and the working area.

A good variable Soldering Iron is important, it will help you save a lot of time normally lost due to heat loss (best soldering temperature 350º).

Solder 60/40 with a diameter below 0.5mm it will help a lot soldering SMD components

Desoldering braille very good to take solder and clean up mistakes.

Good tweezers will be handy when soldering SMD components.

Get a Magnifying Glass, your eyes will thank you when soldering those small SMD components!

This is a overview of my Electronics working station

Since I never soldered SMD components into a Pcb I had to learn, and nothing better than the EEV tutorials one big geek but with loads of information regarding electronics :

Components list: In the end test with a multimeter every trace and component to avoid short circuits and bad Contacts. Use the circuits schematics to know which traces and components should be connected between them.

Soldering

Final FabISP Board

Teste connections with a Multimeter

Programming the FabIsp:

To Program the ISP I followed this Tutorial. Unfortunately Windows 10 isn’t capable of installing the AVR programmer drivers so I had to use the Ubuntu usb boot and used Linux to install the FabISP. Finding out how to Boot from an usb in Windows 10 was a piece of work.
To go to the BIOS you must first Shut down the computer while clicking the shift key:

Shut down + SHIFT Then turn the computer On while clicking the f2 key.

Turn On + f2 Once you are in the boot screen you have to go to the boot menu and Enable "Launch CSM" and in Security menu Disable "Secure Boot Control". Then choose boot from usb in the save and quit menu if it isn’t available you have to repeat the process to get to the Boot menu again and you will have the option to boot from usb.

Enable "Launch CSM"

Disable "Secure Boot Control"

Choose Pen to boot in, Save and quit Once in Linux I started Programming the ISP as explained in the tutorial but I had a couple of errors mainly "Fuse error 1" and took me a bit of time till I figured out what was the problem, I had a small conducting material connecting two traces. After using a compressor to clean the board and re-tested the connections I retried programming the ISP and it was a success!!

Avr and FabISP connection

Terminal message of ISP programming