Table of content

• Assignment
• My Work
• Group assignment
• Board and Component
• Schematic Design
• Select Component
• BOM
• Wiring
• ERC
• Board Pattern Design
• Grid Settings
• Ratsnest
• Design Rule Settings
• Make Board Patter
• DRC(Fabcity Design Rules)
• Outline
• Milling
• Soldering
• Program and Test
• build .hex from .ino
• write program from linux
• write program from mac
• Files
• Lessons Learned
• References

Here is a datasheet of Attiny1614

• Attiny1614 datasheet
• Attiny1614 datasheet(Japanese)

Attiny1614 echo board is shared at FabAcademy Embedded programing page.

Here is a summary of component for the Attiny1614 echo board. The parts is less than ISP(AVR) programmer for Attiny44/45 etc. because AVR-1 series micro controller allows to program by UDPI interface (does not need to 2x3 pin ISP) and to omit the crystal because micro controller itself has internal / external clock options.

For the assessment requirement that says "add (at least) a button and LED (with current-limiting resistor) ", I decided to add LED, resister and switch to my board

1) download libraries for EAGLE from gitlab,

2) Extract archive and open "fab.lbr" from control panel in EAGLE.

3) Create project (project name: echo1614)

File > New > Project

4) At project, create schematic.

(Project) New > Schematic

5) Open new schematic

6) select component from library.

Example: Header pin (1x6pin for FTDI) - "CONN_06_FTDI_SMD_HEADER"

7) Open component in schematic view.

8) If you cannot find component at library, you can look for it at Ultra Librarian

9) Find what is at your inventory.

10) Find what is at your inventory.

11) Check "EAGLE" and download it.

12) downloaded ".scr" file cannot be imported directly.

File > "Execute Script", then you can open the ".scr" file and import it into the library.

Here is what I imported.

After download component, you can export "BOM(Bill of Material)" from EAGLE.

BOM of my echo board: week06_echoboard1614_BOM.html .

Then I wired the schematics. I used some commands like:

• move: move the component
• rotate: rotate the component
• net: connect between components
• name: add name of components
• value: add value of components (ex. 1k, 10K (Ω for resister))

sample echo board pattern

I follow the board pattern of sample echo board. Actually, it's not usual case to write connection under the parts (by Tamiya-san's review)

For stabling the voltage of tact switch when the switch is off, I added pull up resister to the side of S3/S4 of switch.

After wiring is completed, we can check ERC(Electrical Rule Check). We can check if the circuit is correct electrically.

At schematics, "Tools" > "ERC"

Set grid to 50 mil. Display "on" shows grid to board pattern pad.

"Change" > "Width" > "0.016" （0.016 mil inch = 0.40 mm)

It's good to change the grid to 0.025 inch for drawing detail path.

At the Board Pattern view, you can run "Ratsnest" for checking unconnected line.

If anything happens after running ratenest, it's OK.

At "Tool" > "DRC" > (File)Tab and "Load", load design rule file From downloaded library,

Change minimum width of drill to 16mil(0.40mm) from 25 mil.

Put the "SCHBRD(switch to Board) button and draw the board pattern.

If DRC("Tool">"DRC") reports error, you need to correct it. I checked warning and refine the path.

Sometime, you need to write path from the center point of reg. Or you need to switch to schematic for putting name for component

After completing to write board pattern, make the every traces as a group and move it to the cutting area.

1) Checked polygon and select the layer of "48: Document"

2) Created outline.

Rounded corner is good not for hurting the hand.

3) Checked outline.

Firstly, I had narrow width between edge and trace area. However, too small length from edge will bring un expected electrical error or physical error in adapter connection.

I calculated

3) Exported png file to local storage. Check the dpi=800 and the physical length (38.1mm x 30.1mm)

The files exported are here

load "w06_echo1614_top.png" into mods

traced path with 1/64 inches endmil.

• Tool diameter: 0.39mm
• Cut depth: 0.2mm
• max depth: 0.2mm
• offset number: 4

Checked if the cut path calculated by mods run through correctly and there is no short (connected part unintentionally).

clean the surface of the copper with steel wool.

Materials are from Kannai inventory

IC and LED has polarity.

1st pin of IC(VDD) is marked on the surface of ATtiny1614.

Anode side(positive lead) of LED is for IC pin. Cathode side of LED(with narrow green line) is for GND.

Assembled.

I tested where the path should not be connected. Though it was difficult for me to test tiny parts covered by round solder, finally I could finish the test and completed to assemble my echo board!

1) On Arudino IDE, Arduiono > preferences, I confirmed "Additional Board manager" has a URL of "http://drazzy.com/package_drazzy.com_index.json"

2) Checked the place of a setting file of Arduino(preference.txt). Then I close Arudino IDE and opened the preference.txt of Arduino.

Added the build path of build.path=/Users/tatsuro.homma/Arduino/build/to the "preference.txt. You need to shutdown the Arduino IDE. At mac environment, it's easier to open directly the text file specifying path like "/Users/${user}/Library/Arduino15/preferences.txt" by terminal editor like vim.

3) Re-open the Arudino IDE and "Tool" > "Board" > "Board Manager"

4) Search for "ATtiny1614" at the Board Manager.

5) At Arduino IDE, "Tool" > "Board" and select the board manager that has a name of ATtiny1614.

6) Check the settings at "Tool" in Arduino IDE.

• Board: "ATtiny1614/1604/814/...."
• BOD Voltage: 1.8V
• Clock Speed: 20MHz
• DAC Voltage Reference: 0.55V
• Voltage for UART Baud Calc: Closer to 5v
• UART Pins: TX:5, RX:4

7) "✓" in Aruduino IDE (Validate & Compile)

Then you can get build file at the build path that is specified at 2) (build.path=/Users/tatsuro.homma/Arduino/build/).

Also, downloaded pyupdi from github and extract zip file.

Path of extracted pyupdi.py at xbuntu is: /home/fablabkannai/FA2020/pyupdi/pyupdi-master/pyupdi.py

Firstly, I tried to write my program from my Macbook Pro. However, I could not make the pip3environment at this point. This is because my macbook pro environment is configured for Python2 and repository of pip is referred to my company's pip repository. I came up with an idea to make the separated virtual environment for python3 library.

As I cannot save my time because of time constraints at the activity at Fablab, I left my mac and run $ pip3 install intelhex pylint pyserial and download pyupdi at the xbuntu laptop at Kannai. Afterward, I resolved this and successfully wrote my program from macbook pro (see below 13))

2) Connect and check the devices

xbuntu (USB Type A for serial communication)
|
USB-Serial converter cable (FTDI)
|
echo board (FTDI 1x6 pin)
echo program
echo board (UPDI 1x2 pin)
|
UPDI(1x2pin)-FTDI(1x6pin) board
|
FTDI(1x6pin)-USB board
|
USB TypeA(female)-USB TypeA(male)
|
xbuntu (USB Type A for programmer)

3) Check devices

At first, I could find only the device for serial communiation and could not recognize the device for the programmer. After re-plug the USB type C-A adapter and change it for the cheap one (that has track record at Kannai), it worked!

4) write program

Firstly, I could not write program. The pyupdi.py raise an error with messages like "Incorrect echo data", "Failed to chip erase using key" or "Failed to enter NVM programming mode" etc. However, after changing the USB adapter and re-plug the converters, it worked! So, in my case, it worth checking your adapter and connection status.

5) confirmed echo program

Before doing echo, I run sudo chmod 777 /dev/ttyUSB1 after specifying the USB port for serial and add authorization. In my case with linux, I needed to do this every time I re-plug the echo devices.

Then I run miniterm and check echo program successfully.

It looks that miniterm is contained by pySerial.

1) (Mac) setup for macbook pro laptop of UPDI programmer and serial communication with ATtiny1614.

I wanted to have mac environment as that is my main machine.

• setup python3 virtual environment using pyenv (terminal in/out memo1)
• install the required packages(pylint, intelhex and pyserial)(terminal in/out memo2)

3) (Mac) Install pyupdi enveiornment (via pip)

Firstly, I downloaded pyupdi.zip from github. However, downloading .zip requries additional work to check path and specifying explicitly in command or symbolic link.

4) (Mac) program an echo program from mac

5) (Mac) Completed to test echo program uccessfully