08 January 2011

FT817 Interactive Frequency Reader: weights...

I have assembled a circuit of the work-in-progress "Interactive Frequency Reader" and weighted it: about 90 grams without the CAT cable to the FT-817.

This weight includes the circuitry, the 16x2 LCD and the 4x4 matrix keyboard.

Must not forget to add the enclosure weight too!

The assembled circuit confirms that the hardware design has reached a stable version, as well as basic firmware functions. Now I have to think of a user friendly, menu driven?, interface.

05 January 2011

Macro for cameraphone from viewfinder lens

I have come across an article on Hack a Day about building and adding a macro lens to a cameraphone at almost no cost. It requires a lens from the laser head of a DVD reader, and according to published pictures and tutorials, we are talking about a very small part.

While looking inside the 35mm camera (see previous post), I gained access to some lenses and ... guess what? There's one that can be used as a macro extension for a cameraphone!

It is the viewfinder lens, the one where the photographer was looking into before the digital camera era. It is larger than the DVD laser head, so it is easier to handle and mount on an adapter (to be constructed).

This addition works by reducing the minimum distance at which the camera can focus, so that you can get closer to the subject and in fact capture more details.

Let's see how my 3.2 Mp F2.8 auto focus cameraphone behaved when holding the macro lens in front of it.

The sample was a 2 €cent coin at sunset, that you can see here side by side to the lens:

(picture shot without the macro lens, obviously)

Let's hold the lens in front of the camera and get an interesting detail (click on pictures to see them 1:1):

Or, zooming in at full resolution on the focused area:

If I had shot at the same distance but without the macro lens, this would have been the result:

As last, with and without the macro lens side by side:

Now I have to figure out a way to hold the lens in front of the camera.

04 January 2011

What is inside a 35mm point&shoot camera

After few days in the hands of my daughter, a point and shoot 35mm camera plastic has started to break apart... time to put it aside and start opening it up.

It was a Minolta Riva Zoom Pico with a motorized 35-60mm zoom lens and autofocus. It did allow me to experiment with photography, and it took good pictures.

Anyway, I never opened up a photocamera, so I was curious to see what was inside.

I was surprised to find "enough" electronics, all mounted on a flexible PCB fit between the inner body and the outer shield. The electrolytic capacitor of the flash (220 uF, 300 V) was fit inside the film roll cylinder: a very smart arrangment. Everything was a tight fit and I bet it was hand assembled back in 1994 or so. What else can be taken off and recycled? Here's a list:
  • flash strobe with circuitry
  • small screws
  • whitworth 1/4" nut (plastic)
  • small plastic gears
  • DC stepper motor
  • lenses
  • (zoom) objective
  • photoresistor
  • IR LED
  • 200 pixel sensor from the autofocus
Out of all electronics in the list above, very little can be reused in other projects, the easiest probably being the flash strobe circuitry once the pinout is sorted out. On the PCB there are very few "useful" components.

The zoom objective has many wires making it almost impossible to control it from the outside (zoom, focus and shutter), so it is stuck in the "rest" position.

Lenses can be used to experiment with light.. maybe one of the small biconvex lenses from the autofocus could focus the Sun and set something on fire?!

Last but not least, around the camera body there are some metallic springy contacts that could become a Morse key.