Cai Webcontrol for outside lights

[siafu]

Hello all,

I have a Cai webcontrol board hooked up to a relay that controls my outside light.

I have a photo resistor with a 1k resistor and this is what triggers the analog input set to turn the relay on and off, in turn switching the lights on and off.

Everything was working perfectly up until yesterday.

Now for some reason the analog input reading is all over the place.

Normally when it worked correctly, I had it set that when it reached 7 the lights would turn on, then when it reached 11 the light would tun off.

As this is an analog input I needed to give it a little buffer as as it was getting dark or light, the reading would jump a digit or two up or down.

Since yesterday, the reading is all over the place, at some point it's 12, then could run up to 50, then back down, then back up to 100, and the lights go on and off.

I noticed that this happens at night,l as I get email notifications that the lights are on and off. During the day, I think it's stable, because I don't get notifications, but will have a look at day break.

The only thing that I did, the other day, was reset the router that that webontrol is plugged in, and I also unplugged the then plugged in the web control board. Nothing else was done to the board ot the settings.

The photo resistor and 1k resistor is powered by output 8 of the webcontrol board. If I tun off output 8 then the lights stay on, as the analog reading dumps to 0. And I can control the lights manually on and off by controlling output 8. Like I said had it set up like this for a while now and all was working fine.

At this time this is the way I can have the lights on.

Any idea why this is acting this way?

What should I check, I'm not very electronic savvy, everything I learned was from this board, especially from Lou and Cai.

Thank you in advance for your help.

 

[BraveSirRobbin]

I would try to bypass the photoresistor by shorting it, or removing it and just connecting the leads that went to it together and see if your analog input still swings. If it does then the internal power supply went bad or the analog input is bad, To eliminate the power supply disconnect anything going from it and measure its output with a meter and see if it's stable.

 

[apostolakisl]

It sounds like you are dealing with a very small voltage range on your analog input. Single digits in cai represent hundredths of a volt. (.01v). CAI has a range of 0-10 volt reporting at 10 bits (0-1024). In other words, the difference between "7" and "11" is only .04v. That is going to be very suseptible to even the slightest noise on the system.

 

[BraveSirRobbin]

Is output 8 a ten volt output? If so, I am wondering how exactly his system is wired that would merit such small voltage values into the analog input.

 

[CAI_Support]

When he enabled X10 RF support, TTL 8 will output 5V to power the X10 transimitter. I would recommend to power the photo sensor using humidity sensor pin 3, where can provide more current. TTL output can have max 10 mA output current.

Since the photo resistor is exposed to the outside, it is easy to be damaged by environment. If you have another photo resistor, you can make another light detector to see if replacing it would help. Since WebControl's analog input has over-voltage protection, it is not likely to have problem on the A/D input itself.

 

[siafu]

Hello everyone,

Thank you for your input, I checked all you said and I think I fixed the problem.

I went up on the roof where the photo resistor is installed and noticed there were some droplets of water inside the casing. We had a lot of rain lately (Seattle) and water got in there.

While I was up there I tested the voltage with a meter, and I'm getting just under 5v, this is normal from what I understand the ttl outputs is suppose to provide. Then I put my had over the sensor, but it did not act as it normally would, the values to go down, Sure it did a bit bit not like it did before.

So I had another light sensor, exactly of the same type, and tested that one and all is appears to be back to normal. I tested the original sensor with my meeter and the values are not the same as the new one, so must be damaged.

While I disconnected the faulty sensor, I shorted the two wires that go to the board, and the value went to zero, and stayed there. I assume this is normal? They did not fluctuate at all.

I have the photo resistor sensor in a casing, basically in a flashlight head, and I thought I sealed it pretty good originally, but water still got in there. But the enclosure was exposed to the elements.

Now I positioned the enclosure differently, more protected by the air duct structure, so the rain can't really get at it, well at least not as before. Hopefully this will keep it dry.

Now probably will need to a=make some adjustments when it starts to get dark, to get it where I want to trigger on and off again. At this time, the values do fluctuate somewhat, but maybe this is due to clouds rolling by?

Also, I had the x10 option off always on this board, but I just tested it, but turning it on, and the reading on the analog input went to zero.

Thanks again for all your input, it helped me figure this out.

 

[apostolakisl]

Is output 8 a ten volt output? If so, I am wondering how exactly his system is wired that would merit such small voltage values into the analog input.

CAI only has 5v outputs. But you can use something else to power your analog device up to 10v (depending on the hardware revision). If you are feeding the analog input 5v, it should read 512, 10v 1024, 1v 102, etc.

5v inputs is very popular. Many of your analog reporting devices are sold in a 5v model, so it works quite well. Pressure transducers for example.

 

[siafu]

Hello again,

I5t appears to be working as it did before. While daylight was dropping, so was the reading, as before, very little fluctuation, maybe a digit to two digits.

So the water getting in the enclosure was the culprit it appears.

Thanks again to all for your posts and suggestions.