5. Electronics production¶
Individual¶
For this week’s individual assignment I produced a in-circuit programmer using the CAM tools available in the FabLab. To do this I closely follow two sources, this tutorial and Maha Alshamsi’s debugging.
Milling¶
RML files¶
First thing I did was obtain the trace and outline .png files provided in the tutorial.
Then I went into http://mods.cba.mit.edu/ to convert the .png image into a .rml that the machine can read.
Going into RMB>Open Server Program>Machines>Roland>SRM-20>PCB png brings up the screen below, these are the modules used for the conversion
After that going into RMB>Open Server Module>File>Save brings up the module below, connect this to the output pictured below and set the origin x/y/z to 0.
Set the tool diameter/cut depth as to what will be used on the actual machine then press calculate which will produce the .rml file, same process for the outline remembering that it will use a different tool to cut through the PCB.
Machines¶
Onto the machine, I decided to use one that already had a sheet and block secured inside it as there was plenty of space to make my ISP.
On the connected computers, after turning on the machine, I saw these controls. The machine cuts upwards and to the right so it was important to find an appropriate space. I used the controls to move my head and set the x/y origin.
After that I secured the bit in place and spun the head up, I lowered it until it barely touched the surface and set that as my Z origin. Then I moved it up before spinning down.
I loaded the trace first and did my cut which took a while, after it was finished I changed the head to a larger one to make deeper cuts for the outline, set my Z origin like I did before and cut it out in just the same way.
After removing the PCB from the backing, I had my trace complete.
Soldering¶
With the board complete it was time to solder all the components in.
I wrote the names down on a piece of paper then stuck them onto it using some double-sided tape, this held them in place and prevented me from mixing them up due to how small they are.
I followed this tutorial in order to ensure that the I was soldering properly as I had not done it before
Following the schematic, I used the LED mode on the multimeter to ensure I was attaching them the right direction.
This was my result.
I had to come back later to solder a jumper I missed
At another time I made a 2x3 pin ribbon cable using a wx3 pin connector a, a 6 wire ribbon, and a hammer
Software¶
As I said at the start, in order to program the ISP I closely followed Maha Alshami’s updated tutorial, I downloaded the programs mentioned as:
WinAVR20100110, replace avrdude.conf and avrdude with the equivalent files from avrdude-6.3-mingw32.zip
Open system PATH variables and ensure that the /bin files is added to the system PATH.
I connected Hashim’s ISP and using Zadig I reinstalled the drivers as libsub-win32 (v1.2.6.0)
Using the commands
I checked to make sure all the programs were installed as intended.
I connected my ISP to Hashim’s ISP using the ribbon cable I made earlier, then connected his ISP to my computer. As can be seen I had mixed up the red and green LEDs but that did not affect the final function of the ISP.
With that I changed directory to the firmware I wanted, and used the commands:
make flash
make fuses
make rstdisbl
To finish programming the ISP
Group - Ahmed Almarri¶
For this week group assignment I tried milling in two ways (Conventional & Climb) by using a (1/64) size bit.
The first trace did not come out well, a lot of factors could have played into this but it was likely the base not being secured.
As seen, only the first five traces came out clearly while the rest didn’t in both Conventional and Climb settings.
Climb:
Conventional:
