Week 11: Networking

This week we are tasked with communicating. We are assigned with the task of designing microcontroller boards that talk to each other in a networked fashion

What to Make?

Some ideas for this week are

• hello radio
• Stained glass light box with LEDs inside
• asynchronous comm example

Here are the steps:

I read once that the key to a long and happy life is unfinished projects. At this rate I'll live to be three hundred and forty.

Design Board in Eagle

My bridge components in board view in Eagle

My node components in board view in Eagle

The pngs

This week I used Neil's example to design the asyncrhonous communication example. I increased the width of the traces by a ton, moved components farther apart and added a ) ohm resistor so I would have fewer traces runing under my microcontroller.

Vinyl Cut Board

Loaded up my png in fab modules and adjusted the settings slightly. A force of 49 and a speed of 2.5 with a pen force on the machine dialed at 1 worked well. I also adjusted the tool diameter to a lower setting to get traces spaced farther apart.

Weed The Board

It is easier to weed if your cutter has actually cut all of the way through

Gather your parts

I gathered my parts and placed them on the double sided sticky tape with a label.

Stuff and Solder the Board

I wanted to use lead free solder for my circuit so I found some lead free solder in the bin, turned my soldering up to 825 and soldered away. It was not much worse than regular solder! This part was a bit tricky with the vinyl cut traces. I guess the adhesive on the copper is really sensitive to heat so whenever I'd heat the traces to solder them they'd move and squirm around. This was very frustrating. Also flooding a component with solder and then sooaking it up with the copper braid didn't work well AT ALL because the traces moved all around when I was soaking things up and melded together. The connections to my microcontroller look very messy and hideous. Mounting directly onto glass worked much better for soldering but was not without it's headaches. Need to practivce soldering more to actually get my microcontrollers solder without the use of copper braid

Program the Board

With lots of help I tried to program the board adn kept getting errors that my connections were bad... so....

Check all connections

I checked all of the connections with a voltmeter and added solder or removed solder where needed

Debug Board and Program to light up!!!

I worked to debug the baod, resoldering traces, checking all connections and retrying to no avail. Many things broke in the process need to start again? with a new board :(

Results

• Nothing works yet
• This makes me very sad
• If I had a circuit that measured sadness my results would break the circuit
• Add real results here when I get my board to actually work!!

Tools/Materials Used

For designing:

• Eagle
• Photoshop

For Making:

• Vinyl Cutter!!!!!!!

Materials:

• copper boards
• components
• copper adhesive
• hot glue
• copper paint, copper foil

Lessons Learned

• Make sure your vinyl cutter cut all of the way through your component before weeding
• The heat gun will crack glass
• The soler braid will not work do not try it- or try it in peril
• Be meticulous about your design. Ensure all connections are properly made.
• If you want to vinyl cut keep your traces large... keep a printout of your intended design so you know which components you need to repair
• Flooding a component with solder does not work when soldering a vinyl cut circuit
• Solder faster
• Spend extra time pressing down your traces- the ahesion will matter later
• The sticker substrate doesn't work well. Use something else
• Your traces may move around a bit when you solder- if you can design your circuit with a bit of wiggle room so you don't inadvertantly create a short
• I make things harder than they have to be
• The voltmeter is an excellent tool to trace paths and connections
• Things are easier to figure out when you're with someone experienced.

Conclusions

• Start earlier.
• Even if you've done something before it doesn't mean you won't make new rookie mistakes
• Designing a circuit well, even a simple one is harder than it seems.
• Time is the only real commodity in life. Spend it wisely.

Next Steps

• Recut board
• Stuff and solder and program board
• Make board actually do something
• Weed vinyl cut board directly onto glass and make glass light box, investigate conductive paint, thread and fabrics

Files

Copyright 2013 Kathy Sinclair