ELECTRONICS PRODUCTION


    
     
 Group Assignment
          
     In this assignment I have to:
      *Characterize the design rules for my PCB production process: document feeds, speeds, plunge rate, depth of cut (traces and outline)
      and tooling.
      * Document the work.

      
 Machine Test:

  I downloaded the test file from the FabAcademy site
  
w5_1
 
  To generate the cnc machine Gcode file I have used fabmodules.
  
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  First select "image (.png)" from "input format".
  
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  A new window appears, select the image:
  
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  Then I choose the output file format "depending on my machine" 
  
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  After that choose the machine process "first process is trace":
  
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  Last, change the settings:
  
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  When click "calculate" the path simulation starts to show the final board.
  
 w5_8 w5_9 

  
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Individual assignments
  In this assignment I have to:
  * Make an in-circuit programmer by milling and stuffing the PCB, test it, then optionally try other PCB fabrication process.

ISP milling:
To make ISP circuit, I downloaded the traces and interior design from this link. :
After that, usinf fabmodulesagain to gernerate G-code. 
Now as described in week7 I milling my ISP using CNC machine.

16_1 
 

16_1 
 

Soldering:
In my ISP, there are next component: ATtiny44 microcontroller, 2*3.3V regulators, (1KΩ, 499Ω, 100Ω, 10kΩ) resistors, (1uF, 10pF) capacitors 
and 20 MHz oscillator.

 w5_12  

In Libya we don't have a SMD components for sale, so I bought Fab Academy start kit online but I didn't find 100Ω resistors in it. 
I used DIP resistors instead. Also USB connector isn't available.
Programming:
To program the board, Fab Academy present a tutorial for different operating systems.
My issue: The board doesn't work. After check the connection by using multimeter I found a short between (Reset and MOSI) and some 
bad connection. I soldered them again and start programming.

1. Burn Bootloader on Microcontroller:
To burn the Bootloader to ATtiny44 microcontroller we use the Arduino UNO as an ISP, first step is upload an example with name "ArduinoISP" to 
the Arduino UNO boardr.

schematic 
 
2. Wire Connection:
The connections between the ATTIny44 and the Arduino Uno is shown in the following table:  

schematic 
 
And the connection is described:

schematic 
 
3. Uplaod Arduino as ISP program:
After choosing ATtiny44 board and select the oscillator frequency from "Tools", upload the program using "Upload Using programmer"

 schematic week7 
  
4. Download Needed Softwares: 
According to operating system (I am using Windows), We need to download next programs and files:

  • Download and Install WinAVR 

  • Download the drivers for Windows

  • Download the FabISP Firmware 
After downloading firmware.zip extract it to desktop and find file named with (makefile). Open it using notepad and replace:

    AVRDUDE = avrdude -c avrisp2 -P usb -p $(DEVICE) # edit this line for your programmer
    with this line:
    AVRDUDE = avrdude -c stk500v1 -b19200 -P COM13 -p $(DEVICE)
      "Don't forget to change com port number"
Now using (ctrl+R) to open command prompt, type "cmd" then "enter". When it open type "cd Desktop\fabISP_mac.0.8.2_firmware".

    schematic 
    
Now, type "make hex"

    schematic 
    
Now, type "make fuse"

    schematic 
    
Finally, type "make program"

    schematic 
    
Now it is done. To start using the circuit as ISP we must remove the pridge "or 0 Ω resistor".