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Topic: LDR Photoresistor and resistance (Read 1 time) previous topic - next topic

wolframore

Some of the modules have a sensitivity adjustment (trip point). These modules have a comparator perhaps Schmitt trigger built in so it saturates at a given brightness or dimness (is that a word?).  The one you need does not have this circuit and what you need to actually get a range of values.  
Bad Boys Race Our Young Girls But Violet Generally Wins - Get Some Now :) - ELI ICE man

Bjerknez

Some of the modules have a sensitivity adjustment (trip point). These modules have a comparator perhaps Schmitt trigger built in so it saturates at a given brightness or dimness (is that a word?).  The one you need does not have this circuit and what you need to actually get a range of values. 
Okay. probably the best answer so far. :)

I can't see that i have done something wrong here. Other than used a wrong LDR sensor.

But, i'm not 100% sure...

Ron_Blain

You started with ordering photo resistors and asked the difference in part numbers. Then no comment? Now you say you have modules. Post #2 you state this is the module I have less any link? You are all over the map and nobody knows exactly what you have. You have been told and had it explained numerous tomes in other forums how to do what you want to do and just left things hanging.

You want to measure 4 or 5 light levels then just build a simple circuit. Take a Vout and use your code. You have an analog signal. The module we ended up with is nothing close to what you started this thread with so what's it going to be?

Ron

wolframore

It's a simple problem.

This one gives you continuous values it's just an LDR with a voltage divider



This also gives you a signal out but it's amplified



This has a comparator circuit to output a 0v or VCC based on a threshold set by the potentiometer


Bad Boys Race Our Young Girls But Violet Generally Wins - Get Some Now :) - ELI ICE man

Bjerknez

Thanks Wolframor :)

I think you just solved my problem. I just have the wrong LDR for my use. The other sensor i tried is not mine. Just one i barroved of a friend. But this was identical to the first module you posted picture of.

I think i have to order som of theese :)

jremington

#20
Mar 30, 2020, 06:28 pm Last Edit: Mar 30, 2020, 06:35 pm by jremington
You have an LDR module that works fine.

You just don't know how to use it properly, and you won't get anywhere proceeding the way you have, so far in this forum. I'm out.

Bjerknez

Yes, it works, but nok the way i want. The problem is for me solved.

My goal is not to be a king in this forum. Actually i have learned wery much the last three month. For 4 month ago i didn't know what an arduino was.

Now, i building this:


Youtube is that platform that have given me almost all answers. Inn here i have never felt welcome.

wolframore

Nice work!  Looks pretty good.  I see some good techniques in there.  Have a look at larryd's posts about how to prototype... he's got some amazing ideas and you might enjoy it.  Perhaps you can demonstrate what i does?
Bad Boys Race Our Young Girls But Violet Generally Wins - Get Some Now :) - ELI ICE man

Bjerknez

Thanks. I'm not a pro, but this circuits works perfectly. Just some mounting to do :)

Yes, larryd has made som awsome things :)

Bjerknez

My english is not wery good, but i can try to explain what it does, ors what it should do :)

When its finnished this box going to control temperature in my basement and i hav connected it with blynk that shows me temperature and humidity in the basement. I also going to connect an heater with relay. An lcd screen has now been mountet in the box cover.

I have also an separate temperature warning sensor innside the box that gives a warning sound and send me notification to phone when the box gets too hot.

I will also mount a fan in the box. Most for fun. :)

Ron_Blain

So if the object is temperature control how does light levels and LDR schemes figure into it?

Ron

Bjerknez

For this project i just need a ldr for the lcd to go in sleep mode when light is off. It can go days between my visits in the basement and lcd is the most power consuming unit in this project. Not for the money, but for the potensial heat innside the box.

Just remember that this project is most for fun. I startet with one thing, and ended up with many new ideas that was implentet.

But it actually works wery well and the system has runnes for several weeks now without problem :)

Ron_Blain

OK that makes sense but the question begged. Then all you need is a single channel of Light/No Light.

Ron

Bjerknez

OK that makes sense but the question begged. Then all you need is a single channel of Light/No Light.

Ron
Yes, to this project yes. But i have an other project also :)

Bjerknez

I found an standalone photoresistor that came with the Arduino Kit i bought for several mounth ago. It worked perfectly and now i regret bying a bounch of the LDR modules i have.

But i'm learning on my way, and i did not break the bank, so i will survey :)

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