Assignment

This weeks assignment is to create FabISP board.ISP stands for In-circuit Serial Programmer i.e. the device can program chips that are already integrated into their target circuit.

PROCESS-

The machine used for milling the board in our fablab is ROLAND MODELA MDX-20.

Steps-

• preparing

  First make sure that the bed is tightly screwed in the machine.
  The board to be milled must be placed above a sacrificial layer using a double sided tape. The sacrificial layer is requiresd because it will prevent the drill bit from cutting into the board if there mistake in measurements.
  The Drill bit 1/64” is used to mill the traces and 1/32” is used to cut the board out.
  

• Milling

  Fab Module is used to operate the machine.
  Input format is image(.png) and the Output format is Roland MDX-20 mill(.rml).
  Load the image and select mill trace(1/64).
  make path and set the (xmin,ymin).
  click make.rml and send it!.
  
  
  
  select begin Milling to start the milling operation.
  
  
  
  
  
  After milling the traces, load the image for the cut-out and select cutting(1/32). repeat the above steps for cutting the board. I encountered a problem while cutting edges.While the bit was moving across the surface of the borad, thus ruining the circuit traces i had milled earlier.
  I doing some tinkering, I found the cause. The milling bed was not properly screwed on and hence the uneven surface caused the problem. so i had to do the cutting process again.
  This time i got the proper cutout of the board.
  
  
  
  

• Stuffing

  The next step is to obtain the necesaary components. if not placed properly, some of the components like resistors or capacitors can get mixed and become difficult to tell apart. To avoid this, I made a list of all the components in a paper and stick a strip of double sided tape parellel to the list.Then place each component across from its respective place in the list.
  
  
  
  The next step was to solder the components in the correct placements. Keep the tip of the soldering rods clean.
  While soldering, take care not to apply too much soldering iron because it will affect the working of the board as most components will be close together.
  
  
  
  
  
  

• Programming

  
  Steps for programming FabISP:
  1. Install the necessary software for your operating system and download the firmware.
  2. Then you edit the Makefile.
  3. Set the fuses / program the board
  4. Verify that the board is working properly
  5. Then you need to open up the jumpers to make it a programmer.
  I ubuntu, Installing the software consist of the following commands-
  Open Terminal and type:
  

  sudo apt-get install flex byacc bison gcc libusb-dev avrdude
   

  Then type:
  

  sudo apt-get install gcc-avr 

  - type "y" when asked to do so by your system
  Then type:
  

  sudo apt-get install avr-libc 
   

  Then type (may already be installed):
  

  sudo apt-get install libc6-dev
   

  Download and Unzip the Firmware:
  Move to the desktop
  

  cd ~/Desktop   
   

  Download the firmware from the Fab Academy Electronics Production page.
  

  wget http://academy.cba.mit.edu/classes/embedded_programming/firmware.zip 
  

  Unzip the firmware
  unzip firmware.zip
  Connect the mini USB connector of the FabISP into computer and a separate pogrammer to the 6-pin programming header. (another working FabISP or the ATAVRISP2, a USBtiny, an AVR Dragon, etc.).
  Edit the makefile using command:

  nano makefile

  
  A window will open containing the Makefile. Go to the line that says:
  AVRDUDE = avrdudthe e -c avrisp2 -P usb -p $(DEVICE) # edit this line for your programmer. since i was using Atmel ice, i changed it to:
  AVRDUDE = avrdude -c atmelice_isp -P usb -p $(DEVICE)
  
  Now typed the following commands and check each results:
  

  make clean

  make hex

  make fuse

  make program

  This is where i encountered a problem, during burning fuse. i got following error:
  
  
  
  since i was new to soldering and electronics in general, i couldn't figure out the problem. My fabmate daniel found the problem after some checking. It seemed that i had added a 10k resistor inplace of 0 ohm jumper and the jumper inplace of resistor. So i desoldered both components and resoldered them correctly.Then i tried making fuse again and was succesful his time.
  
  After that, programming the board was also succesfull.
  I finally got a working FabISP!!!