HOW TO MAKE (ALMOST) ANYTHING

contact // irina chernyakova

1 [0912] FINAL PROJECT PROPOSAL 2 [0919] COMPUTER CONTROLLED CUTTING 3 [0926] ELECTRONICS PRODUCTION 4 [1003] COMPUTER CONTROLLED MACHINING 5 [1010] FINAL PROJECT UPDATE 6 [1017] MOLDING / CASTING / COMPOSITES 7 [1024] EMBEDDED PROGRAMMING 8 [1031] 3D SCANNING + PRINTING 9 [1107] INPUT DEVICES 10[1114] INTERFACE + APPLICATION PROGRAMMING 11[1121] OUTPUT DEVICES 12[1128] MECHANICAL + MACHINE DESIGN 13[1205] NETWORKING + COMMUNICATIONS 14[1212] FINAL PROJECT DEVELOPMENT 15[1219] FINAL PRESENTATIONS

1 schematic design using Eagle (CAD for electronics!)

This week we're designing a board and have added an LED and a button. Eagle is CAD-like program for electronics. We downloaded Neil's fab library, which includes basic components that can be added to the drawing. The Eagle tutorial was extremely helpful, and Eagle is easy to learn. First, open the file in SCHEMATIC. When Eagle asks if you'd like to open the .brd (BOARD) window, say yes. Always have the two windows open. This allows the Board to update its components and connections as you draw them in the schematic. In this window, you can drop in components and establish all the relationships between parts. I modified the original drawing by adding an LED at pin 6 and a button at pin 10. In order for the LED to receive the right amount of power, we've added a 1K Resistor (R2_500). Below is the schematic window with the resultant board. You can use the ERC command in the schematic window and the DRC in the board window to check electronic and design rules; it seems that Eagle spots errors but would not necessarily detect if your board is actually drawn correctly and will work.



added components:

[LED and resistor] [button]


board design png:

[After soldering, and programming errors for several hours, we spotted the error in the board. I accidentally connected the pins with a route, which caused the entire board to short circuit..] Below is the first wrong board, then the right one.

2 milling the board on the Roland Modela

Milling was much faster this time. I changed the speed from 4 mm/s to 3.7 mm, and the cut was much smoother and cleaner. There was an issue with fabmodules, as the path generator was not compiling multiple cuts. Shahar showed me that checking the XY paths under 3D settings solved that problem.

3 stuffing the board

Overall, stuffing was smooth. Too many small parts. Be very careful while soldering the LED, the crystal, and the ATTiny. After soldering, I connected the board with an FTDI cable to my computer, and the LED turned on! I don't actually think it was supposed to, given my board was actually wrong and probably had a short-circuit...

3 “programming...”

A big thank you to Filip, Theodora, Moritz, and Brian Mayton for all the help! Lesson learned – attend the debugging session.
All my knowledge below.

First, check that the FabISP we made in week [3] is actually programmed and recognized by the computer.
About my MAC > More info > USB

If it is, great. Next, connect the FabISP to the computer using a tinyUSB cable, connect the FabISP board to your new board with a 6-pin wire, and finally connect back the computer using an FTDI cable.

• Download the hello.ftdi.44.echo.c and the hello.ftdi.44.echo.c.make files from the website. The C file is a text file that contains the code necessary to instruct how to execute the given program. Each .c files has to have a .make counterpart. You can edit Neil's .make file for new projects. Place this files into designated directory on your computer.

• Also download CrossPack, which installs the AVR code; as well as an FTDI serial server. (Download MAC 64 bit)
  Both of these are necessary to run through terminal.

• Open Terminal. [Thanks Moritz for the commands!]
  Open the directory in which the files are located. [cd Documents/, press Enter; ls to list all files within the directory] For example, my sequence below. Listing all the file within the directory helps spell file names correctly...
  
  

• First step is to create a .hex file. This transfers the .c instructions into bit information [0 0 0 0 0 1 0, for example].
  The command for this is make -f hello.ftdi.echo.c.make. My problem at first was simply that I misspelled the file name..

• Once you have a .hex file, you need to program the FabISP fuses.
  The command for this is make -f hello.ftdi.44.echo.c.make program-usbtiny-fuses. If something is wrong with your board, it will give you the message below- most likely Double check connections and try again. Try switching the pin cable, make sure Pin 1 corresponds to Pin 1 on both boards.
  
  

• Run make -f hello.ftdi.44.echo.c.make program-usbtiny-fuses again. If your board is working, connections are right, avr will accept and execute the insructions.
  
  

• Finally, run make -f hello.ftdi.44.echo.c.make program-usbtiny to program the .c instructions onto the board.
  
  

I was having a issues with programming the fuses. After an e-mail exchange with Brian, I thought the 20 mhz crystal may be the issue, so I replaced the crystal, replaced the LED, re-flowed the connections on the board and still no luck. Turns out the issue was a route connecting the the traces of the ATTiny microprocessor...
Thanks to Theodora for letting me use her board to practice programming!

4 “programming... part two..”

C + Terminal
Moritz suggested I download TextWrangler to edit text for C, as Text Editor tends to damage the code. I tried to adapt a blink code from Yeon Wha's website, as it looked somewhat understandable. Moritz suggested I try this code that he wrote - I first used the blink code, then modified the blink code to blink in sync with certain beats and time variations. This is the blink.c file and the blink.makefile. To run this terminal, use the same commands as above, but replace the file name.

- make -f blink.c.make
- make -f blink.make program-usbtiny-fuses
- make -f blink.make program-usbtiny

Images of the code; you can download the files by clicking on file names above.

blink video

Arduino
David Mellis gave us a tutorial on using Arduino, which you can download here. To use Arduino, make sure your board is connected.
First, select the correct board: Tools > Boards > ATTiny 44
Then, slecect the correct programmer: Tools > Programmer > FabISP
Finally, Burn Bootloader.
This completes the set-up. Afterwards, you can run several of the example scripts in File > Examples > Basic > Blink or Fade, etc. Make sure to change the LED pin number to match your board.

BLINK VIDEO
FADE VIDEO