week 4
- electronics production
- Assignment: design and make a FabIsp board
Future operations with personal computers and Arduino or any other types of machines will be achieved via an ISP circuit.
It is a very small USB device, we will need to program all the boards we will do in the next months.
This circuit presents a micro-USB port to connect it with a computer on a side, a micro controller Attiny 45 to be programmed in a second phase and a 6 pins port to let it dialog with any external machine in the future.
The dimension of the components, like capacitors, resistors or diods, made the soldering operations a little difficult. As my fingers seemed too big for handling them.
In the next weeks we will start also with programming and designing our personal circuit, but for beginning, as none of us have any experience (or so) about electronic manufacutring, it was just to copy and follow the schemes posted on the Archive.
Personally I had a very little experience, through Arduino's "getting started" manual, with building a little and simple board, but surface-mount components size has made soldering critical.
Once more time, the group of Barcelona Fab Lab has joined the forces together and more or less we all accomplished the assignment.
I downloaed the Eagle file from schedule page on Fab page and opened it with Eagle.
On it we have two visualizations: a Schematic view and a more real one where it is possible to design the paths of the traces following the constraints wetted on the schematic view.
So first it is to select from the library the components we need. The put them in relation as the reference schematic indicates.
Then with the Modela it is to set 2 passages: one with the 1/64 tool to mill the traces and another, with the 1/32 tool for cutting the boards.
Basic is to set a sacrifice board under the one you want to cut and that both are orizontal.
Soldering has not been easy for the “nano” size of the SMD component version.
Anyway I could menage to program the ISP after few trys.
Avr device finally blinked green.
Here you can download the files to make it
