For the assignment of week 4 which is to manufacture a programmer circuit, I fabricate the board by cnc milling.The milling machine allows the creation of 3D prototypes in materials such as plastics, wood, ABS (Acrylonitrile Butadiene Styrene), nylon, acrylics and modeling boards. It also allows the manufacture of printed circuit boards in bakelite for the development of electronic projects. In this case I used a Mdx-540 milling machine with the following characteristics:
- work area: 400 x 400 x 150 mm.
- Cutting material allowed: Plastic, MDF, Acrylic, bakelite
- Speed: 7.5m/s
Precision test (group assignment)
For the group assignment we have carried out a precision test of the Roland CNC milling machine.
1/64"
0.001"
For individual assignment I manufacture the FabTinyISP developed by BRIAN who makes an excellent explanation of the manufacturing process.
PCB Fabrication
The first thing to do is Download the PNG files for the traces and the board outline:
PCB Fabrication
The first thing to do is Download the PNG files for the traces and the board outline:
The next step is to generate the machining files, for this I use fabmodules.org, This platform allows generating the routes for milling, following is a detailed description of the steps to follow to generate the traces file and the cutting file.
1. Import .PNG File
2. Select output format and select Roland mill (.rml)
3. Select Process and select PCB Traces (1/64)
4. Edit parameters
5. Save file
To the PCB Cut I use the similar steps
1. Import .PNG File
2. Select output format and select Roland mill (.rml)
3. Select Process and select PCB Outline (1/32)
4. Edit parameters
5. Save file
The next step is to configure the milling machine
1. put the bakelite piece in the machine fastened with double sided tape.
2. Identify the location of the 1/32 and 1/64 tools
3. Set XY Origin
4. Set Z Origin with the sensor
Start milling
1. Import .rml files
2. Select tool
3. Setting spindle rotating speed in 10000rpm
4. Start milling
5. Welding electronic components
List of electronic components
1x Attiny45 Microcontroller
1x green LED
1x red LED
2x 499 ohm resistors
2x Resistances of 1k ohms
1x 100nF Capacitor
2x zener diode 3.3v
2x Resistances of 49.9 ohms
1x 3x2 pin header
Software Installation
In this case I am using Windows OS, Is necesary install some drivers and software to upload the firmware to the board. For this I used de Brian tutorial.
2. Install the Atmel Studio 7 Download here
4. Download avrdude, unzip the archive, and copy the archive inside to C:\Program Files. Download here
Go to the Start menu and open the Control Panel, then go to System. From the left pane, choose "Advanced System Settings". Under the Advanced tab, click the "Environment Variables" button.
Paste the ubication of the following files: avr8-gnu-toolchain, GnuWin32 and avrdude
Sanity Check
Download de firmware source code and extract the zip file Download here
Edit Makerfile, open with SublimeText or another text editor
Program the ATtiny45
Connect to USB the two devices, open git-bash at the location where the firmware is located and run "make flash"
Next, run "make fuses"
Next, run "make rstdisbl"
Finally, remove the bridge to turn the board into the programmer rather than the program
Programmer validation
You can validate the correct installation of the firmware in the devices administrator
Include a ‘hero shot’ of the board
Issues and remarks
To solve this problem you must use a more updated version of the avrdude, in the following link you can find more information . The version that I use you can download it here
DOWNLOADS