peterlite
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Oregon Scientific RMR500 replacement using the Pi Zero W.

Sat Mar 04, 2017 3:31 am

The Oregon Scientific RMR500 is a neat using displaying temperature and humidity from indoor and outdoor sensors via wireless. Oregon Scientific no longer sell the outdoor units, making the RMR500 useless. Instead of buying an expensive new model and all new sensor units, I looked at the Pi Zero for a replacement sensor. Everything was too hard. Now we have the Pi Zero W.

The central unit could be a Pi 3. I have two and I will soon have a small screen dedicated to one of the 3's for use as my EEE, my Electronic Environmental Evaluator. Each sensor will be a Pi Zero W. I will use a Wifi router in the middle to increase the range and to let the Pi 3 talk sun/sleet/surf with the outside world.

The outside sensors can be in a waterproof plastic box. Add a battery and a small solar cell. I could monitor the voltage from the cell as a way to measure solar radiation.

I could put the sensor on a springy pole and add the GPS hat. I could then calculate wind strength and direction from the deflection.

I could put the pole on a flotation device then calculate the ocean water level by the vertical movement but I doubt that will be of much use. By the time a tsunami reaches this level of our building, an accurate measurement of the depth might not be the highest priority.

The important thing is the flexibility to add any type of sensor and as many sensors as I want. Forget the limitations of an Oregon Scientific product.

My starting point:
https://www.raspberrypi.org/education/weather-station/

I do not need all the sensors and will start with just temp plus humidity. I had analogue sensors for an Arduino. The following item looks interesting but not suitable for outdoor use and it is dependent on some board that is not suitable for a small outdoors sensor.
https://www.raspberrypi.org/learning/se ... _humidity/

What would be the minimal setup for a small outdoors sensor?

peterlite
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Sat Mar 04, 2017 3:48 am

This looks like the most accurate outdoor temperature sensor I could connect direct to the Zero.
https://www.adafruit.com/products/381
The cheaper version for indoors:
https://www.adafruit.com/product/374

peterlite
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Sat Mar 04, 2017 3:54 am

Barometric pressure: https://learn.adafruit.com/using-the-bm ... spberry-pi
I can have this inside the case and a small hole in the case to let the air pressure equalise.

peterlite
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Sat Mar 04, 2017 3:59 am

https://www.adafruit.com/products/2899
I live next to the ocean. UV A and B measurements are important. This one does UV A. Can it work from inside a glass or plastic case?

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mahjongg
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Sat Mar 04, 2017 1:33 pm

peterlite wrote:https://www.adafruit.com/products/2899
I live next to the ocean. UV A and B measurements are important. This one does UV A. Can it work from inside a glass or plastic case?
simply try put the material between light source and sensor to see if that plastic or glass is blocking your UV light source.
If it is then no, you cant operate it behind that material.
Different kinds of glass/plastic have different transparency for UV light, but they will all block some of the light, its whether you can live with it thats the question.

wikipedia may have answers about transparency for UV for different materials.

peterlite
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Sun Mar 05, 2017 1:09 am

I found a page talking about window glass, car glass, etc. It seems that some countries have standards for glass in specific uses but not here. Either plexiglass or polycarbonate was listed as the best plastic if it has no uv inhibitor. It will end up, as you said, with a test. They said all glass filters some uv so it depends on thickness.

UVC is filtered out by our atmosphere. Glass blocks UVB. Thin plain glass filters some UVA. The sensor measures only UVA. If the loss is something like 50%, I can just multiple the measurement.

peterlite
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Sun Mar 05, 2017 1:21 am

Late last year, I found the OS outdoor temp/humidity sensors online for $35 plus postage. I could have orders two for $80 posted. They had none left when I tried to order the next week. The sensor runs for more than six months on one AA battery.

Updated with purchases:
Pi Zero W $18
Solar cell 10 watt $27
Converter/charger $12
Battery SLA 12 volt 6.5Ah $29.95
Voltage step down $1
Still to buy:
Waterproof case $15
microSD card $8

$110.95 before adding, sensors, wires and wiring. I guess it will return some value when I add the other sensors not available for the OS device.

For some of the items, I can bypass the "double the price because we are selling it in Australia" tax. For others, I can double the price by buying the Adafruit versions of things. The Adafruit versions often plug in without a dozen extra components on a big breadboard, saving time and money for the extra components.
Last edited by peterlite on Wed Apr 05, 2017 6:58 am, edited 2 times in total.

peterlite
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Fri Mar 24, 2017 6:14 am

The Pi Zero W cost me only about $18 shipped.
The plastic waterproof case I may use was $3 on sale in the local shop. Not UV proof but it will be in the shade.

peterlite
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Wed Apr 05, 2017 7:04 am

Purchased some more parts. Recycling some parts from other projects. Have not yet tackled sensors. Temp then humidity then wind speed. Do not know what after that. Whatever I use, they have to survive salty wind. Cadmium, nickel, and chrome plated screws fail outside in 3 months. Only stainless steel survives. The exposed sensors have to be well made or cheap and easy to replace.

peterlite
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Tue Apr 18, 2017 7:27 am

Solar panel arrived today. It looks big. It will cover my whole project container and then some. Still waiting on two more parts.

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Gavinmc42
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Sun Apr 23, 2017 2:25 am

It will be interesting to see if 10W is going to be enough.
Solar Pi's could be useful for all sorts of things.

Hmm, wonder if light reflectors, might give you a boost.
Mirrors/Stainless steel/Aluminum panels?
Deploy them for Winter to help with lower output.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

peterlite
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Sun Apr 23, 2017 6:47 am

10 watt looks good for Sydney/Spain/LA type areas. 20 watt for London type areas.

peterlite
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Sun Apr 23, 2017 10:32 pm

Hmm, wonder if light reflectors, might give you a boost.
Image
http://raszl.com/blog/beauty-solar-power-plants

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Gavinmc42
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Re: Oregon Scientific RMR500 replacement using the Pi Zero W

Sun Apr 23, 2017 11:33 pm

Got some aluminum coated mylar I have been saving.
Might have to water cool the panel, get bonus hot water :P
What reflects visible light but not IR wavelenghs?

20watts for Zero W plus camera?
Here in Brissy if you have a 1.5KW system, you should get 6Kwhrs.
So 20W is about 8Whrs which averages out to 0.33 watts continuous over the day.
That does not seem enough, say 15V panel that's 22ma, sw regdown to 5V is about 50ma.

Must be something wrong, calculations say need 100W for camera system on 24/7 :o
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

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