W4 Electronics production

Orders and procedures introducer.

ISP (In_System Programmer )

Some microcontrollers could be programmed while installed, they are called "In-system programmer" or ISP. There are many ISP protocols, we will use the AVR developed by Atmel because all the microcontrollers that we will use are Atmel.                       

During the Fab Academy we will perform several electronic circuits and they will needed to be programmed the microcontroller to perform actions between the inputs and outputs. The ISP will allow us to program a microcontroller.

During this week we will get used to several tools available on the Fab Lab: Kokopelli software, Model, Soldering, etc.

Summary

Learning electronics production tools

Make the FabISP in-circuit programmer.

Download hello.ISP.44 files from Fab Academy web page,
get used to Kokopelli, learn how to mill a Printed Circuit Board (PCB) on Modela MDX-20, learn how to soldering components and installing firmware.

Content (linked):

Assignment:
FAB ISP TUTORIAL

Fab ISP Tutorial. STEP BY STEP

Step 1

Deciding which ISP make

On Fab Academy web page, there are several alternatives ISP. 

I have chosen Neil's ISP (hello.ISP.44) for two reasons:

1. It seems easier to solder than others.
2. I prefer to connect the ISP by an USB cable, in order to have all PCBs far from my PC and the ISP full supported on the table.

According to Anna Kaziunas, Neil's hello.ISP.44 is based on David Mellis's FabISP wich is based on USBTinyISP, wich is based on Dick Streefland's Atmel USBtiny. 


Step 2

Download all files

There is a new file extention that I have ever seen, used at Fab Academy (.cad): 

This file extention belongs to Kokopelli. With Kokopelli you can edit a PCB through code lines. It is developed by Matt Keeter and Neil Gerghenfeld. 

A basic Kokopelli tutorial here. 

Download all files

If you know how it works Kokopelli, you will need just the file.cad, becouse traces, components and interior are made from file.cad:

hello.ISP.44.cad
board
components
traces
interior

I had edit the hello.ISP.44.png  and add my name.  I've tried to mill it but I couldn't. Then I come back to Neil's PCB traces.

After all, I realize that while editing, I have reduced resolution very much and that were not good for Modela. This is something to consider!

Step 3. Fab Modules

Setting Fab Modules

First, open the fab modules:

a.- Open a terminal
b.- Tape: fab
c.- Choose Roland Modela
d.- Input format: image (.png)
e.- Output: Roland MDX-20 mill (.rml)                         
Settings on fab modules Roland MDX-20 for traces: 
f.- Mill traces: (1/64) 
g.- Load.png: hello.ISP.44.traces.png                                
h.- Offsets:4      z(mm):-0.5
i.- Make path 
j.- Make.rml  
k.- Check: total size, zero point (move to xmin, ymin).
l.- send it!  

Settings on fab modules Roland MDX-20 for interior:  
f.- Mill traces: (1/32)  
g.- Load.png: hello.ISP.44.interior.png
h.- Offsets:1      z(mm):-1.5
i.- Make path  
j.- Make.rml  
k.- Check: total size, zero point (move to xmin, ymin). 
l.- send it!  

Step 3. Modela

Setting Modela MDX-20

Chect list to work with Modela:

  1. Clean the the surface before milling
  2. Check that have a sacrified layer under our work layer.
  3. Check that is complety flat. 
  4. Check de (0,0) point before start to mill. Find it manually.
  5. Start to milling
  6. When finished, take out the PCB.

Step 4

Soldering components 

Solder the components on the PCB with tin thread using an iron.

This is very manual step. You will need be handy with iron and tin thread to solder all the components on PCB right. Practice is caught after a while.

  1. 1 ATTiny 44 microcontroller 
  2. 1 Capacitor 1uF 
  3. 2 Capacitor 10 pF 
  4. 2 Resistor 100 ohm 
  5. 1 Resistor 499 ohm 
  6. 1 Resistor  1K ohm 
  7. 1 Resistor 10K ohm
  8. 1 Resistor 0 ohm
  9. 1 "6 pin header"
  10. 1 USB connector 
  11. 2 jumpers
  12. 1 Crystal 20MHz 
  13. 2 Zener Diode 3.3 V 

Step 5

Programming

AVR is the protocol used in Atmel, so this will be the very first to do: installing AVR on my PC. 

I have followed this tutorial.  

Here it is my FabISP finished.