Dusk/Dawn sensor

Post by **Bwired** » Fri Aug 15, 2008 3:19 pm

default is fast rate:

This mode is battery consuming but gives a high accuracy.
This results in a fast sampling rate of 1 minute. An RF packet is transmitted if a temperature change of 0.5 degrees Celsius is detected.
Every 40 minutes an alive RF packet will be transmitted.

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">I have been testing with this settings for a while now and its working great. It's measuring light from 0 to 5 volts.
Nice thing about it that its only sending a message when the data is changed and even then it takes like max 60 seconds to send. So fluctuations are very minimal. If nothing changes every 45 minutes a heartbeat message is sended.
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Post by **Alexander** » Fri Aug 15, 2008 4:03 pm

I have been testing with this settings for a while now and its working great. It's measuring light from 0 to 5 volts.
Nice thing about it that its only sending a message when the data is changed and even then it takes like max 60 seconds to send. So fluctuations are very minimal. If nothing changes every 45 minutes a heartbeat message is sended.
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Post by **Bwired** » Fri Aug 15, 2008 4:21 pm

mhhe, perhaps Bert can explain this.
And yes the sensitivity is not good that every cloud is changing the outcome. The big changes are only in the morning and evening.
I use this device for opening and closing electrical curtains and in combination with UV, Wind, Temp en Rain sensors for the sunscreen.
Here you see readings for today, I only log to in my database when the value is really changed!

Post by **Alexander** » Sun Aug 17, 2008 12:00 pm

Can somebody check the current value, because i don't trust the values i get for the last 11 hours:

02:00 = 4,96v
03:00 = 4,96v
04:00 = 4,96v
05:00 = 4,96v
06:00 = 4,96v
07:00 = 4,96v
08:00 = 4,95v
09:00 = 4,94v
10:00 = 4,93v
11:00 = 4,93v
12:00 = 4,87v

Post by **Bwired** » Sun Aug 17, 2008 12:17 pm

Check both tables above your post!

Post by **Alexander** » Sun Aug 17, 2008 12:41 pm

15-08 was a shiny day i guess. It's not at the moment. 4,87 V currently can't be right.

Post by **Bwired** » Sun Aug 17, 2008 12:47 pm

Yep it's not good at all, my reading is now 0.1

Post by **Alexander** » Sun Aug 17, 2008 1:00 pm

0.1? With that value the sun is shining on your transistor right? Its cloudy here, no sun. Because i don't get the values right, i don't have any good reference (other then Bert posted about the spot light).
I thought it worked, because with a bright light i got < 1 Volt (close range) and 3.xx Volt at a distance of 20 cm from the bright light.

With a cable in between it doesn't work (sticks to 2.xx volt), so that isn't the question anymore. I've the same setup as you have.

Is there a way to see if the diode/transistor is in the right direction installed? Other than the length of the legs.

Post by **Alexander** » Sun Aug 17, 2008 4:50 pm

Okay, found it. Changed the transistor (cathode&anode). Now i do get 0,12 Volt cloudy weather and 4,71 Volt if i cover the transistor in my hand.
Now, i hope there is a difference that can be measured between cloudy weather and sunshine.

Post by **Alexander** » Sat Aug 23, 2008 2:32 pm

Anybody an idea why (see picture) it happens that i receive peaks to 4,xx Volt when the sun is shining. The RFXSensor is behind glass, the BPW85 is not covered.

Post by **Bwired** » Sat Aug 23, 2008 2:45 pm

those are your clouds [:D]
no idea....

Post by **Alexander** » Sat Aug 23, 2008 3:24 pm

That would be nice

I do know the BPW85 is not for solar measuring. The amount of sun light can't be measured that good. On one day, full sun, low voltage. On another day, sun, but with thin clouds, the voltage is the same. Begin this week i had a event trigger on 0,05 Volt for lowering the screens. Today, i've to set it to 0,20 Volt to trigger the event. Begin of the week, that voltage (0,20) was when the sun was behind the big clouds.
The BPW85 is perfect for turning the lights off or on. Not measuring the sunlight i guess.

What sensors do you use to lower your screens (and up ofcourse). You mentioned the rain sensor, but else? (with what sensor do you measure the sun light?)

Post by **Bwired** » Sat Aug 23, 2008 6:38 pm

For sunscreens it's a bit more difficult, for me the voltage needs to be at 5 volt, the UV sensors > 0, no rain, no hard wind and that for a particular time-window.
I'm also busy with my little solarpanel, if it's runs the sun is shinning

see it at http://www.bwired.nl/Camptz.asp and push preset 6.