Thanks, Zach.
I live in Limburg, 200 km away from the coast and thus usually 2 Bf less than the coast.
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A BME280 or DHT22 is better suited for measuring ambient temperature. The BME280 also provides humidity and pressure data, which might be useful in the future.
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Hi Cas
Firstly what does 2 Bf mean, I assume some sort of temperature difference.
If your “Limburg” is Limburg Ave near Canberra, ACT I can understand your desire to get out of there during the winter. The only other "Limburg"s i find are a few scattered around Europe.
Now the important bit. I personally think I would seriously look at a passive system as linked above.
Reason being I would not like to leave an electrically operated automatic system unattended for an extended period. Particularly the “home grown” variety and indeed some of the really cheap commercial products on offer these days. I am afraid my confidence level is not up to leaving such a product for several months.
I understand your roof is heavy @ 100kg but that can be overcome.
Reduce the weight of your roof by framing with aluminium or steel as suggested earlier. Have a look at some of Bunnings steel framed gates consisting of mainly 25mm square light steel tubing. All very easy to cut to size and assembled with self drilling “Tec” screws. I have a couple as doors under the house and are very easy to handle. 4m would have to be done in 2 or 3 separate pieces I think but would be nothing like 100kg.
Use more than one control device.
Does your roof have to be in one piece. Can it be in 2 or even 3 sections. This should decrease the weight of individual sections considerably even using timber.
Cheers Bob
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Bft - Beaufort, the unit for wind power.
I live in the Netherlands, where Limburg is a province touching both Belgium and Germany. So it is about 200 km inlands from the sea. Therefore wind speed will decrease a lot due to forrests and cities that slow down the sea wind. In the summer it’s 5 degrees Celsius warmer that seaside, and in the winter it’s 5 degrees Celsius cooler that seaside.
For simplicity’s sake I want only 1 motor to push the roof.
As for cost so far I don;t think it will be very expensive:
- Pico board 6 euro
- 5V power free old telephone charger
- temperature sensor 11 euro
- power relay 230V 20 euro
- scissor jack 10 euro from car junkyard
- electric motor to wind up/down scissor jack ? maybe 40 euro?
So in total about 100 euro. I was surprised by the low cost for the Pico board. As a retired Drupal CMS backend devoper with Perl and PHP experience I think I will have no problem programming in Python.
Any future additions may include a rainmeter, as I have many other subtropical plants that require water like Tree ferns (Dicksonia Antarctica) and other ferns Cyathea.
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Hi Cas
Ah, that Bf. I have heard of the Beaufort scale but not very familiar with it as I have never been in a position to worry about it.
I found that one. There is only one I could find in Australia which is a street name in a Canberra suburb. It is also about 150-200 km rom the sea.
You can probably forget any reference to Bunnings (a large hardware store chain here) but I would be surprised if you could not find something similar in your area. My comments about using aluminium or steel to reduce weight still stand.
If you look at the passive devices you have NO motor. Also the descriptive text says it is quite OK to use more than one of these to lift the vent.
But you seem determined to use a motor.
AC or DC motor? If you use limit switches for safety you will find it easier to arrange to back off the switch in the reverse direction with a DC motor. Also you need to brake the motor in case it keeps going past the switch and just goes to the end of travel then stalls.
If you don’t want limit switches and rely on programming the Pico to stop the motor then good luck with that. I think the Pico is aimed at the hobby, experimenter, developer market. I don’t think it is meant to be left unattended for extended periods doing some automated task. I personally would not trust it as far as I could throw it. Too flakey for me. I fear that if your motor is not stopped in a fail safe manner and goes to a stall situation you could well come home to a fire.
But those are my thoughts alone. Maybe I am over cautious but in my working life I have always worked in an environment where reliability is paramount. Just got used to this I suppose.
Cheers Bob
I have a concern with using an old telephone charger. If it was used to charge NiMH battery’s in really old phone system you should not use it; if its like the modern mobile phone chargers it might be ok. But, some of these phone chargers turn themselves off when the current drain is too low.
Make sure its puts out a good regulated, filtered, steady 5V, transient spikes will kill the Pico’s Switch Mode Power Supply chip … eventually. (personal experience) The VSYS pin is limited to 1.8V to 5.5V.
With respect to @Robert93820 comment about the reliability of the Pico, I have one turning on a watering solenoid every 4 days for an hour. This has been running reliably for well over 2 years, never turned off. I also have another one on top of my roof in a weather station that collects sensor readings and sends them to a base unit, this has been working well for about 4 months now. The watering solenoid is driven by a relay that can switch AC and DC up to 10amps or so. In my case it switches 24 VAC at about 0.5 amp.
I am very impressed with what the Raspberry Pi Corporation put into the Pico, and its pretty cheap.
Cheers Jim
Hi Jim
I would agree with that.
I have noticed over time that your projects are always scaled with plenty of head room or fudge factor. This is a sure recipe for reliability. It would be less reliable if everything is operated right on its limit which seems to happen a fair bit.
The plan to use an old telephone charger would be a classic example of coddling something up with whatever is available.
With this outlook I think some of my reliability comments would be well founded. This should be changed to a “proper” power supply with a capability of about 3 times the expected current.
I suppose some of my comments could be read as a direct attack on Pico reliability. What I am saying is that I PERSONALLY would not use a Pico in an unattended situation. Maybe OK if everything malfunctioned in a “fail safe” manner. Up till now I have not seen any thoughts on this.
Not a lot f time in the grand scheme of things. a zero after the 2 would be better.
Probably why it is still working. Would be interesting to turn it off for a couple of days to see what happens.
Cheers Bob
The idea is to erect the conservatory every November and take it apart every April.
This gives me a natural view on the palm more than half of the year.
As for the phone charger I am happy to upgrade to a more reliable option, especially since it will sit outside in sometimes damp condition. Please recommend something
Hi Cas
How damp. It would not be a good idea to have a power supply sitting in any sort of “damp” environment. You may care to rethink that bit.
As for a power supply. I did suggest above a supply of 3 times the expected current. The reason behind this is if the system experiences a momentary current surge for any reason a supply with more capability has a better chance of absorbing this without interfering with its voltage output. This will be quite important as you say this system will be unattended for extended periods. As for an actual figure at this stage no one has any idea exactly what will be connected to this supply. So any number would be a guess. Not a good idea.
Cheers Bob
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