Week 4 – Electronics Production

This week assignment is required to make FabISP in-circuit programmer using a provided schematic diagram for the whole circuit which will be viewed by a special software called “Eagle“. The FabISP is a system programmer for micro controllers which we will use it inside the fab lab for this week assignment that will help us to program the micro controller on the circuit board in the final step. , as I faced some difficulties to run this software in my ubuntu system but finally I find a code that just to be typed inside “ Terminal “ application and the code is “ ./ eagle run “ then the software will be run automatically without any needed complicated installation as the following pictures.

Now the software is opened and ready

* For Cutting The Board ( Milling )

First I need to create the circuit board which will be used in soldering later , therefore we will follow the circuit schematic design from fab academy website with this file name “ fabisp.brd “ that this design is very clear and easily can be done in our Kuwait Fab Lab , I use the “ Eagle “ software to open and view the schematic diagram file.

Now we will use PCB board that need to be cut as the above design exactly , but before starting the cutting process there are some preparation steps like : we will use in the cutting machine double boards above each other to avoid machine header mistake broken also if we use a deep depth guess value the machine header can be broken. The double boards are stick tightly above each other by strong sticker tape to prevent the machine header from touching the steel base if we enter some big depth values as a protective procedure for the machine header , the initial guesses for the cutting machine should be very reasonable and slightly changed as the header is so sensitive. All the X,Y,Z coordinations are in millimeters units , for the depth I choose  0.2 mm instead of 0.1 mm and Z-axis should be in negative number and slowly try end error process for the cutting machine coordination to make sure the cutting head touch the board then we will be able to cut the board as the design giving as this step take some long time and must be carefully done.

Finally after we reach the suitable coordinations , the circuit board can be cut and ready , also we should clean it from the traces of cutting process carefully by vacuum cleaner and soft brush then make sure that the cutting process was succeed and follow the above schematic diagram.

* For Soldering

I printed the schematic diagram of the circuit board that we must follow for our assignment and it helps me a lot during the soldering process and I suggest to all who want to use the printed version instead of using their smart phone as a reference. The most difficult part from my opinion is the attiny as it needs to be soldered carefully one end by one end , and any overheating soldering or soldering the wrong position will lead to electrical shortage then mostly you need to repeat the whore process from the beginning so be very careful step by step !

Also make sure to choose the right value for capacitors and resistors , as inside the lab the concentration must be very high and there is many capacitors and resistors values close to each other which is not easily be recognized so we must choose the type and value carefully and not let it fall down or mix with similar parts which can lost your time and effort and decrease the accuracy for the whole assignment process.

* For Programming

Before we start using FabISP , we must program the attiny on it and to do this step we need to use a programmed part that connected to the circuit board ( Called ISP ) and clearly it can be used as USB device after connecting to the personal computer.

* Important Note :

I have some physical disability in my hands and legs which really makes the cutting and soldering process little slow and sometimes difficult to use the equipments but with the strong intention and assistant from fab lab Kuwait instructors everything move smooth and forward then finally I succeed to finish my assignment for week 4.