Yashica 44 - Project Beater

Ok, that was a bit easier than fighting with an LCD connector!

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This circuit has a push button and an LED connected to the full size Arduino board. The code written to the board counts the number of times the button is pressed and when that reaches 11, the LED lights up. There's also a 50ms delay built in to the code to allow for any 'bounces' in the button where the metal contacts spring back. I can't take responsibility for the code, it's an example one from Arduino themselves that I've just modified to count to 11.

I put this together this morning so need to test what happens when I cut the power. If it remembers where in the count it is then I can fit an on-off switch into the power line and the circuit will always remember where it was in the count. If it doesn't, I'll just make sure I always leave the camera wound on as the count will start from zero again.

Once I'm happy with the code, I'll order the Trinket version of this board which is small enough to fit into the back of the camera along with a small lipo battery.
 
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Lol, my mind tends to come up with new options all by itself ;0)

I'm close to throwing the LCD counters out of the window trying to maintain connectivity across a rubber strip between the circuit and screen! The screen is mounted to the metal rear door of the camera which has an indented lip around the window I want it to show through so it's not perfectly flat. The simplicity of a basic led indicator is looking very appealing and the Adafruit Trinket should take up less room than the LCD circuit. I'll need to mount a small lipo battery onto the bottom of the camera door but the one I've got here looks like it will fit nicely. I'm deciding now whether I should include a charge circuit in the camera for the lipo and fix the battery in place or make it removable and save on the space.
 
What!? A whole pound?
 
That's a very complicated domino scoring board. :D
 
stevelmx5 said:
Lol, my mind tends to come up with new options all by itself ;0)

I'm close to throwing the LCD counters out of the window trying to maintain connectivity across a rubber strip between the circuit and screen! The screen is mounted to the metal rear door of the camera which has an indented lip around the window I want it to show through so it's not perfectly flat. The simplicity of a basic led indicator is looking very appealing and the Adafruit Trinket should take up less room than the LCD circuit. I'll need to mount a small lipo battery onto the bottom of the camera door but the one I've got here looks like it will fit nicely. I'm deciding now whether I should include a charge circuit in the camera for the lipo and fix the battery in place or make it removable and save on the space.
Click to expand...

How much power does it draw? might be better with a coin cell or the like if you can get away with it.
 
Funnily enough I've just put a 2xCR2032 button cell holder into my basket and ditched the lipo idea :0) The Trinket and a single LED consumes 9milliamps apparently so the approximately 200mah button cell output should give around 22 hours of constant use. I'll use a simple push button on/off so I can switch off the Arduino when I'm not using the camera which should give me more than enough juice.

I need to test what happens when I cut the power but it shouldn't be a problem. I also need to measure the camera when I'm at home to make sure the button holder will fit but I think it should.
 
I think I've found the perfect combined power/led :0)

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This is made for PC power buttons but will light up with a 3v source so should be spot on. It's 10mm diameter and only 7mm deep so I can mount it into the rear door where the window is and fit the leather skin around it. Only problem is that the only suppliers I've found so far are in China so delivery is on a slow boat!
 
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How about a miniature dynamo geared to the wind on mechanism to charge the battery? (Or, marginally less sillily, a solar cell?)
 
Not a silly idea at all but I think that adding the charge circuit will mean more complication and less space. If I stick to button cells and an on/off switch I can keep it simple (rare for me!)
 
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Ok, I've ordered the Trinket and 2xCR2032 holder. I'm waiting to hear back from the eBay seller about the button to confirm it's definitely latching as their listing says both latching and momentary so one's got to be right!
 
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A quick test of the circuit now I'm home shows that the count resets when the power is cut so I just need to make sure that I don't turn it off mid-wind and remember if it's been wound on or not and I'll be able to turn off the counter.

I think the best option will be just to wind it on after each shot which will also prevent any double exposures.
 
stevelmx5 said:
I think I've found the perfect combined power/led :0)

View attachment 71566

This is made for PC power buttons but will light up with a 3v source so should be spot on. It's 10mm diameter and only 7mm deep so I can mount it into the rear door where the window is and fit the leather skin around it. Only problem is that the only suppliers I've found so far are in China so delivery is on a slow boat!
Click to expand...

Ok, this isn't an option. The seller came back to me today and confirmed it's a momentary switch, not latching even though the listing states "Latching switch, press once for ON and again for OFF" so I suggested they update their description :mad:

I've now got two options. A basic push on-push off latching button to turn the counter circuit on/off along with a separate indicator LED or a concealed tilt switch which switches the circuit on when the camera is tilted forwards (too see the back and wind it on) then switches off when it's stood upright on its' base to shoot or when put down. I like the idea of the tilt switch but there's too much risk of the circuit being broken accidentally by not keeping the camera tilted forwards enough which would mean the frame counter would be incorrect.

I think I'll incorporate a simple on/off button and the LED into the rectangular window where the LCD screen used to be fitted until I 'encouraged' it off last night in disgust ;0)
 
Mark 2 is ready for wiring :0). I've been looking online all day at different latching push buttons/switches to come up something that fits into the rear window section without sticking out too much or being awkward to switch on/off. At the same time I've been reading up on sleep commands for the Arduino board so it can conserve battery life as much as possible. When I got home I realised we've got a few cheap Rolson led torches in the cupboard. After liberating their top caps I found the perfect latching push button that fits the rectangle opening exactly :0)

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This button will be fitted inline between the batteries and the Trinket board to interrupt the power. From the testing I've done, cutting the power just resets the counter code to 0 so as long as a remember if I've wound the film on or not, I can switch on the Arduino after taking a shot to wind on and then turn it off again afterwards.

I've fitted the LED through the hole I originally drilled out for the digital counter rest button and it fits quite nicely. I'm not fixing anything in until I've got the circuit wired up and tested but from the looks of it I think it should all fit in ok. I now just need to decide between a red/yellow/green LED, I'm swaying towards green at the moment.

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The back of the led will be sealed and covered so there's no risk of fogging the film which would be really annoying!
 
Few more updates today;

New faceplate fits ok and works better than the shorter piece I made first. I'm not 100% about the text but it will have to do!

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I'm thinking about spraying this in black textured paint to soften it a bit so I'll test that out with another piece first.

I've also got my assembled sprocket hole counter now. I need to sand back the right hand edge slightly to move the button more to the middle of the sprocket hole but it seems to do its job nicely. The button was originally shaped to work one way only so I've shaped it to allow me to rewind the film through it too. It works better one way still so I've got that setup for rewinding the film to reduce the friction on the rubber universal joint with the film.

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I've also been trying out the fit with my button in place on the rear door and I think I'm going to have to mount it outside the camera which I really didn't want to do. The door doesn't quite meet the body with it installed internally which is really annoying me! My two options are;

1) Move the button outside the camera, possibly mounted to the cold shoe near the strap lugs then run two wires inside. It will fit ok here but I'm not sure about the appearance overall.

2)Do away with the On/Off switch entirely and just leave the circuit on all the time when a film is loaded. There's a switch on the battery holder which will control the power but I obviously can't change that when there's film loaded!

Decisions, decisions :0)
 
Ooooo, gadgets :0).

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This is the Adafruit Trinket board that's pretty tiny!

I've used breadboard wiring to roughly test the code after I uploaded it to the board after a few modifications. Happy to say that it's doing the job of indicating 11 button presses which should mean perfect frame spacing.

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Looking at mounting options, I'm considering fitting it below the film counter button bracket to keep it out of the way.

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I'll just cut a notch out of the back of the button bracket to fit it over the board.
 
Steve I've forgotten the detail here. But if the idea is to turn a light on after 11 sprocket holes, as a signal to stop winding, won't the person winding need a bit of warning? Eg short flash at 7 and 9 then long at 11?
 
At the moment, the circuit lights the single LED after 11 button presses which is pretty much a full single turn of the winding knob. I hadn't factored in an early warning because I'll only be winding slowly but it's a fair point.

I could modify the code and fit a second LED which is switched on after 8 holes then the other at 11 to give a bit of warning. I'll have a play with the code later. Cheers
 
Actually, rather than add an extra led, I've found a uk seller for 3mm bi-colour LEDs (red/green) with 3 pins. I should be able to connect each colour pin to a different pin on the Arduino and update the code to light the led red at 8 presses then green at 11 which should give an early warning.
 
Or vice versa? Green... keep going, red... stop?
 
Five read lights coming on one at a time then going out to signal its ready? F1 Style!!

This must be the most advanced film camera ever built, late SLR's and stuff were fairly complex with all the fancy metering etc but none could be used to control a robot if needed.
 
My worry is that maybe this is how skynet started......

:runaway:
 
Mmm, Box Brownies taking over..... Definitely more negatives than positives in that scenario..... Sorry :sulk:
 
If you're going to be putting a computer in it, then it needs a GPS, and a memory card to store exposure info . . .
 
Ok, the Adafruit Trinket board i'm using has a maximum of 5 i/o pins and I need one of those for the button to count sprocket holes. That leaves me with the option of up to 4 LEDs so I've ordered some of the dual-colour (red/green) 3mm leds so can fit 2 of them onto the camera. As each physical LED has 2 inputs for the different colours, I'm thinking of coding something like;

Count to 3 - Light first RED LED
Count to 6 - Light second RED LED
Count to 9 - Turn off first RED LED and light first GREEN LED
Count to 11 - Turn off second RED LED and turn on second GREEN LED.

I'll then end up with 2 green LEDs lit to indicate the next frame is lined up. I did think about the other way round and have red as stop but I think green meaning go might be better. I'll wire them up when I get them and see. It's only a quick code change to switch it around.
 
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Ok, the code is all working now on my full size Arduino and I've modified it to address the 5 I/O pins on the Trinket. I've also cut away part of the counter button bracket so the board can fit underneath it but I can still press the reset button if I need too.

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This is the final circuit that I need to wire up and squeeze into the camera once my bi-colour LEDs arrive;

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I've also stripped a damaged iPhone charge cable to re-use the very thin wiring from it. I'm planning on running just black wiring so it's hidden inside the camera so I'm predicting some frustration as I get positive and negative switched around ;0)

Yeah...should be a piece of cake..
 
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h'mm with all these lights and if the project is a failure you can always hang it on the christmas tree ;)
 
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