Martins Krebs - Fab Academy 2018

- MĀRTIŅŠ KRĒBS -

Fab Academy - 2018

Week 5: Electronics Production

Group assignment:

Characterize the specifications of your PCB production process.

Individual assignment:

Make an in-circuit programmer by milling the PCB (program it, so that you can use it to program your board in Electronics Design week, and in other weeks).

Optionally, trying other processes.

Learning outcomes:

Describe the process of milling, stuffing, de-bugging and programming.

Demonstrate correct workflows and identify areas for improvement if required.

Have you:

Shown how you made and programmed the board.

Explained any problems and how you fixed them.

Included a ‘hero shot’ of your board.

This week we machined a circuit board called an ISP (In-Systems Programmer), which will be used later throughout the program to program other circuit boards we will be making.
Our instructor, Scott Zitek, has a Modela MDX-15 mill to produce circuit boards in the Fablab at LCCC.

The material we are using is a copper clad paper-based board als known as FR2. Fiberglass boards make much better and a more durable board, but, they wear and dull the cutting tools in the mill much more quickly.

In order to mill the board, we needed to access the fabmodules. The fabmodules run best on Linux, which luckily LCCC had desktops set up with Linux and already dedicated to the Mill. I read through the tutorial while Scott was explaining to us about the board and how it was based on the FabTinyStar design that Zaerc made.

We downloaded the traces and outline from fabmodules (seen below)

The mill will run the tool over/through the dark areas and keep the white.

Next, using chrome, we access fabmodules. Once there, click input format to expand the menu. (seen below) Import the traces and/or outline life.

Next, hit output format. For us we used the Roland .rml

Next, go to process and you will get another pull-down menu at the top PCB traces (1/64)

You will see tool/milling settings on the right margin.

Enter your values for tool diameter, offset, and cut depth. (ours was 0.3mm, -1 to fill, 0.3mm respectively)

Lastly, calculate.

The toolpath will be drawn out. You can zoom, and move around to see different angles of the toolpaths with the mouse.

Save your files, make sure your blank board is secured to the sacrificial layer inside the mill, insert & tighten the 1/64" (0.3mm) cutting mill.

The cutting results:

Time to program the microcontroller using what is called "avrdude". Our instructor allowed us to program our controllers through his Linux laptop. Following the instructions from Zaerc's website, Chris Rohal looking over our shoulders, The lab's desktop which had Linux installed, and a copy of fts_firmware_bdm_v1 and makefile was already installed and edited, and using Chris' programmer to help us through roadblocks, we managed to debug and program our "dudes" correctly.

We finishd by heating up the soldering iron and remvoving the solder bridge here (shown below) to lock in the changes.