Week 4: Electronic Production

Tips: Put double-sided tape in copper sheet rear and stick it firmly to work plate.
Then set 1/64 tip - first you engrave traces outer space, then you cut PCB edges. To do that you need a specific key to unscrew tip header and remove previously set tip -if there's one-, put the one you need inside and screw clockwise to block it.

NB: always put your fingers under the tip when you unscrew so as not to let it fall ruinously.

Now, you can open monoFab's software:VPanel for SRM-20.
First step is to set the origin: its position should be in the bottom left of your workspace.
To set X,Y and Z you have to use these buttons: IMPORTANT: setting Z position is what you have to pay more attention to! The far end of the tip is really tiny and delicate so it can easily broke. Therefore it's recommended to change header speed from Continue to 100x
To avoid damages, you should:

• lower header until 3-4 mm between header and copper are left;
• unscrew the tip till it gently touches the plate;
• screw clockwise while holding it with your fingers.

NB: hold firmly the tip so as not to let it be pulled by header while screwing.

Once you positioned X,Y and Z as you want, tell the machine that point is the origin:

Now it's time to mill traces: click on Cut button and add traces .rml file, then just run your work.

NB: first you engrave traces then you cut the outline! The result should look like this: You now have to cut PCB edges. To do that you have to to change tip from 1/64 to 1/32 (follow steps above to set new Z to origin).

NB: origin's X and Y HAVE TO be the same as before, so just move the header to position using button below and then set the new Z.
Run outline cutting pressing Cut button, deleting previous works and adding outline .rml file:
Final result should be like this: IMPORTANT: before soldering, wash PCB with water and soap and dry it. I know it can seem a dangerous action but I found out there's no damage, rather it helps to remove that grease that coul oxidize your board.

Soldering: a tricky way to face with "big hands" problem

I've always know my hands to be a little over common dimensions but I've always seen that as an advantage in slapping people. Thus, for the first time in my life I felt them like an hindrance: electonic components dimensions are in (2-4)mm range!

ISP programming

Actually programming the ISP was to me the easiest part ( also because Simone Guercio) followed me step by step explaining what I was telling to the terminal while writing commands listed in this tutorial.
I suggest you to take time and read the guide because it clearly explain what to do. I will summarize the process brommercial programmer but in steps below you can find how to make it known to your computer editing downloaded file.

ATTENTION: ISP and programmer have to be linked ad shown above, to say it easily, when you link them with SPI cable their mini-usb port have to be in the same direction.

Steps to follow:

• 1-Get AVR programming software(AVRDUDE¹) needed packages.
  
  Commands:
  sudo apt-get install flex byacc bison gcc libusb-dev avrdude
sudo apt-get install gcc-avr
sudo apt-get install avr-libc
sudo apt-get install libc6-dev
  during steps above you may be asked to install also additional packages, answer yes every time.
  
  
• 2-Download the firmware from the Fab Academy Electronics Production page.
  
  Commands:
  cd ~/Desktop
wget http://academy.cba.mit.edu/classes/embedded_programming/firmware.zip
unzip firmware.zip
  
  
• 3-Edit Makefile² if you're not using ATAVRISP2 programmer.
  
  Commands:
  nano Makefile
  A text editor window will open containing the Makefile. Go to the line that says:
  #AVRDUDE = avrdude -c usbtiny -p $(DEVICE) # edit this line for your programmer
AVRDUDE = avrdude -c avrisp2 -P usb -p $(DEVICE) # edit this line for your programmer
  
  Then, if using the USBtiny programmer or another FabISP
  • Remove the "#" in front of the line with "usbtiny" in it;
  • Add a "#" to beginning the line with the "avrisp2" in it to comment it out;
  • save the Makefile
    
    

What was done in this step was just to switch from AVRISP2 to USBTINY -that inclues any on FabISP- programmer.

• 4-Program your ISP.
  
  Commands:
  Open firmware folder if you're not already inside: cd Desktop/firmware
  Then type
  make clean³
  answer should be:
  yourComputer@name~/Desktop/firmware$ make clean
rm -f main.hex main.lst main.obj main.cof main.list main.map main.eep.hex
main.elf *.o usbdrv/*.o main.s usbdrv/oddebug.s usbdrv/usbdrv.s
  type
  make hex⁴
  answer should be:
  yourComputer@name:~/Desktop/firmware$ make hex
avr-gcc -Wall -Os -DF_CPU=20000000 -Iusbdrv -I. -DDEBUG_LEVEL=0
-mmcu=attiny44 -c usbdrv/usbdrv.c -o usbdrv/usbdrv.o
avr-gcc -Wall -Os -DF_CPU=20000000 -Iusbdrv -I. -DDEBUG_LEVEL=0
-mmcu=attiny44 -x assembler-with-cpp -c usbdrv/usbdrvasm.S -o usbdrv/usbdrvasm.o
avr-gcc -Wall -Os -DF_CPU=20000000 -Iusbdrv -I. -DDEBUG_LEVEL=0
-mmcu=attiny44 -c usbdrv/oddebug.c -o usbdrv/oddebug.o
avr-gcc -Wall -Os -DF_CPU=20000000 -Iusbdrv -I. -DDEBUG_LEVEL=0
-mmcu=attiny44 -c main.c -o main.o
avr-gcc -Wall -Os -DF_CPU=20000000 -Iusbdrv -I. -DDEBUG_LEVEL=0
-mmcu=attiny44 -o main.elf usbdrv/usbdrv.o usbdrv/usbdrvasm.o usbdrv/oddebug.o
main.o
rm -f main.hex main.eep.hex
avr-objcopy -j .text -j .data -O ihex main.elf main.hex
avr-size main.hex
text data bss dec hex filename
0 2020 0 2020 7e4 main.h
  type
  make fuse⁵
  If the answer ends with
  avrdude: safemode: Fuses OK
avrdude done. Thank you.
  your ISP has been programmed successfully.

Programming should has work but to double check your ISP works properly, you have to connect it directly via USB to your pc and type lsusb to verify your computer correctly sees it: to definitely feel like Ben Stiller in Zoolander you have to check shell answers you with something like
Bus 002 Device 004: ID 1781:0c9f Multiple Vendors.
If you're trustless (like me) type dmesg and finally feel proud if you see your ISP among devices listed. After you hymn of joy, go back to soldering station and remove 0 ohm jumper to prevent your ISP from being programmed again.

---

NOTES

1:AVRDUDE is the most popular software uploader to send code to flash programmer. It works with a quite large variety of programmer. If you want to make sure you installed it, tipe avrdude in shell and if it shows all the command-line flags and arguemnt you're allowed to use, you did it, otherwise check if the problem come from missing installation or computer's inability to find its correct path -that's usual problem for Windows OS rather than Mac or Linux OS-.

2: Makefile is an utility used in C programming that help keeping track of dependencies while splitting a program into individual functions. Its convenience stays in that you can run several .c files together only by typing make command and also that (if needed) you can edit just part (lines) of it to run different programs instead of compiling a new one. Here a simple tutorial on make command.
Below an explanation from ""Make:AVR Programming"" by Elliot Williams (Chapter 2, page 19):

3: make clean command: to be discovered

4: make hex command: to be discovered

5: fuses: I may say fuses relates to microcontroller's clock speed, but, since my idea of the topic has to get clearer and complete, I just report definitions I found till now ( in "Make:AVR Programming" by Elliot Williams - Chapter 9, page 189 and 191):

CODE EXPLANATION

See week 8.

Conclusions

I admit I was quite lucky to have a working programmer at my first attempt, but the part I liked was that I had to rely just on my manual abilities to get to result.
I found soldering quite relaxing but at the same time somehow challenging. I would have liked to do more, but I think I'll have several opportunities to develop my soldering skills in next future.
Thus, on one side I'm not that satisfied because I just did what tutorials said me to do without diving deeply in my actions' meaning. Therefore, owing to my lack of google-fu I've started to read Make: AVR Programming by Elliot Williams to move my step forward in microcontroller programming; first topics I would like to understand are commands I used to program my ISP.
Moreover, I want to fix some solderings on my ISP and test it again, if it still works properly I'm going to brush some nail polish over my board so as to protect it.

Download

.rml files here

Update 6th June 2017

I realized I didn't prove my FabISP could program other boards itself. During past weeks I designed and developed many PCB and in order to aknowledge my FabISP functioning, I tried to program another board.
To do that, I created a folder with a make file and a C code (see week8 for more):

I then connected the FabISP to my computer and I checked if it was correctly seen with dmseg command:

I then connected Chiara's FabISP to mine and tried to program it.
I so moved into the code folder and ran make -f makefilename.make to create .hex and .out files:

Up to now everything went correctly, but when I tried to send the command to the other FabISP with make -f makefilename.make program-usbtiny I got this error:

Before blaiming my FabISP, I used my Hello board and I so re-ran make -f makefilename.make program-usbtiny command, once the board was rightly connected to the FabISP. Everything went fine this time:

Programming with my FabISP from Silvia Palazzi on Vimeo.