11 Jun
2010
11 Jun
'10
5:28 p.m.
On 11/06/10 21:11, Tony Duell wrote:
Yes there was an LCD... soldered onto the main board.
In this case
the cameras consisted of two PCBs -- the main board with
the CMOS sensor and controller chip, and a switch board with the mode
switch and power switch.
What, no LCD display assembly? I would regard that as _essential_ on any
digital camera I had to use. Is it possible to get any data on the sensor? From
what I recall, driving
CCDs is 'fun' for suitable values of fun. The rise and fall times of the
drive waveforms are critical, for example.
These things used OmniVision CMOS sensors -- as I recall, they're a lot
easier to deal with than CCDs. Nowhere near as easy to use as, say, a
Mitsubishi Artificial Retina (the chip that was used in the Gameboy
Camera) but still not bad. Only problem is that OVT have gotten very
skittish about giving out datasheets -- they used to have a huge bundle
of downloadable datasheets, appnotes and so forth on their website,
including (IIRC) sample code. Now everything's under an NDA, and you
have to commit to buying several thousand chips per month before they'll
even talk to you.
The Micron and Kodak image sensors have a nicer interface than the OVT
chips (and they'll give out datasheets free for the asking) but I
haven't managed to find a UK distributor for them. Digikey stock a few
of them, but the really cool $100 high-speed camera chip (something like
500FPS but only at 640x480 or so resolution) seems to have been ditched.
Shame really, I'd have bought a couple.
I've actually got a lead on a box of ten 640x480 18-bit-colour TFT
panels, complete with backlight inverter. 90 Euros for the whole box,
including shipping from Spain. Pennies on the pound, literally (they're
NEC panels, and the RRP in that quantity is about ?80!). Piss easy to
drive with an FPGA or some TTL if you're that way inclined. You
basically need a dual port RAM (or a single port with a bus arbiter),
one counter that goes up to 320 and another that goes up to 240.
Annoyingly the touchscreen panels cost more than the LCDs -- ?15.74 each
plus VAT, and they're "last time buy, all sales final" so I'll probably
be getting at least one for each TFT and a spare or two...
The idea was to have a handheld device running a standard-ish CPU, then
give it all the basic I/O you'd need to talk to test equipment.
GPIB/HPIB, serial IEC, RS232, SB-bus, ... and a Microchip wireless
transceiver (specifically, the one with the built-in Zigbee/MiWi
PHY/MAC). Add a Tek 4014 emulator, a digital pattern generator and a
logic analyser, and I'm in heaven :)
I once saw a digital camera wit ha 2-position focus
control (normal and
close-up). it dit appear to move the lens on a focussing mount. There was
no autofocus, or anything like that.
That's pretty much what these were, only without the focus switch.
I wonder if you could use front-of-lence closeup
lenses? The resolution
of the sensor in such a caerma is not going to be great, so I doubt you'd
notice any loss of qaulity.
Probably. The macro mode on most decent digicams should do it as well.
Canon PowerShot and Ixus (IIRC these are rebranded as "Elph" for the US
market) cameras seem to be pretty good -- down to less than 1cm with
full AF in most cases.
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/