Zhongwen
Italiano

  Jb MINI vario development steps

 

 


I fly paragliding since 1996… I ended up in China. Living here it has always been a trouble to provide to my students a good affordable mini vario. I fly tandem and I had a couple of mini vario before… very expensive but the life was very short…. Mini solar panel not working or just the electronic stop working… In Shanghai where I live the weather is often bad, and if you cannot fly you have spare time… So I decided to design and build one myself. I was inspired by other projects around, but I wanted to add something…. First of all a shell, then a long autonomy Lithium polymer rechargeable battery … and a piezo buzzer with a nice sound. Piezo buzzers are loud and drain almost no power,l they can be controlled to make any sound from few Hz to (in my case) 5 KHz. I don’t like the electronic to be exposed to dust, water and so on… But building an enclosure it is expensive… so I looked for some small already existing… Living in China gives some advantages about this… you can find everything and the prices are ok… Then I asked to myself, why not printing a logo on it? After a research the logo was printable using 0.03 euros /piece…

 
 
 

Prototyping


Microcontroller experiments Microcontroller experiments
Microcontroller experiments Microcontroller experiments
Microcontroller experiments Microcontroller experiments
Microcontroller experiments Microcontroller experiments
Microcontroller experiments Microcontroller experiments

Designing  the electronic for an already existing shell is much cheaper than to produce a shell to fit your design… So I did the other way around, I found the shell that i liked afer many test.. and then I started to design the PCB

What you need is to learn a cad for this purpose, and then trying to make the PCB with different techniques…  Obviously the password is STUDY...

I decided to learn EagleCad, on Internet you can find plenty of tutorials... then I started to experiment..
I wanted to keep everything small and light. So I chose the microcontroller AT MEGA 328P AU.
I decided to give a try to the laser printer  toner technic. It works in this way: you print the circuit on a heat transfer paper by laser printer. The toner is a sort of plastic; therefore when you will put the copper plate in the acid it will not corrode the copper under the toner (the circuit).
To transfer the toner I bought a grandma  ironing… first time in my life…. Then I used it also to solder the SMD components, checking the temperature with a laser thermometer, trying to follow a reflow curve.
Obviously it takes some practice to understand the right pressure and how to manage the temperature.. but after some try it was ok…   

 

Microcontroller experiments Microcontroller experiments Microcontroller experiments
Microcontroller experiments Microcontroller experiments Microcontroller experiments