OpenSX70 Project!
Joaquim de Prada Fala do seu Projecto para Polaroid SX70 a http://opensx70.com
Segue o seu grupo de facebook https://www.facebook.com/groups/opensx70/
I wanted to replace the Apollo-era PCB “brain” on the SX70 Polaroid camera with a modern Arduino-based easy to program PCB. That would allow to add “manual control” to the camera and many more cool things.
It was not something that had not being done before, at least two commercial projects existed. But nothing existed as open source and arduino-based.
The project is open source for non commercial uses, under Creative Commons “Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)” is free and open for hobbyist NON-COMMERCIAL USE.
My plan was that, it would create a “community effect” and that many people would volunteer to help, sharing their skills. Specially electronics, and coding. It has not really happened (yet!).
So I got all the Repair Manuals I could find on the camera, trying to understand how it works. Fortunately it is quite simple: a couple of switches mechanically activated, a motor, and two solenoids.
(basic camera operation in slow motion controlled by arduino)
So from there I tried, using of the shelf components and arduino boards to “make” a camera. That first camera I knicknamed FrankenSX70
So I figured I could design the board myself (How hard can it be?) So I started with the great Fritzing software
But then I found out that the professional EAGLE CAD could be used free so a switch to it and kept with design. Keep in mind that I had never used EAGLE nor design a PCB, also that the openSX70 was not a simple “my first board design”:
custon outline that had to exactly fit in the camera
SMD components (where do I start?)
Very limited real state
For me, the initial openSX70 design would be a two part thing. The “main” PCB inside the camera. And the “control” dongle that you connected through the camera flash socket. The flash was a challenge: the way it was originally design to use the flashbars only three cables ran straigt from the PCB to the socket. So I had to:
be able to operate flashbars and electronic flash
control de “manual” options of the camera
fire an external flash via a PC-compatible socket
have a information LED
the current “downsized” uDongle.
(early dongle PCB)
The central part of the project is the main SX70 PCB.
As of today the red main PCB “chocolate” is working although with some flaws. First I ran “Blink” to test the board as an arduino.
Then I tested the full camera operation
The board has both an “optinal” piezzo buzzer and a BH1750 light meter:
I started with a 3.3V regulator, to run the Atmega328p, initially at 16Mhz, then at 8mhz. Finally I run at 2.5V. The next generation board “Aladdin” and “Aladdin-FPC” are on the way this will hope will allow me to finally make my first working openSX70 camera! Aladin Gerber file
The new pre-industrial production 5.2 “Len’s and Bellow’s” PCB fully assembled prototype ready camera Prototype #2:
After a mishap with the SEEEDFUSION PCBA service where they placed the BH1750 upside down I got a coupon from them to rebuild the boards. Nevertheless I have build a prototype (3.5) and it seems to work ok. Now I have designed a new board “Pathfinder”. I have corrected a few errors that I had detected in “Len’s & Bellows” particularly the BH1750 placement.
Now I have got the prototype boards from SEEEDFUSION (I always test before comiting to PCBA)
The resason for a new version is the relocation of the light meter chip:
Now, as of June 21st 2018 I have tested all functionallity in the “Pathfinder” PCB and have ordered production of 10 more “test” PCB fully manufactured by SeeedStudio Fusion PCBA.
I am “spreading” the word and trying to make the project know all over. I am doing and sending a few highly experimental kits.
Finally I will include a few sample photos.
