Is (low) response time really a key requirement for this application? If I understand the concept correctly, the idea is to let openHAB automatically control the blinds (tilt to open/close position), presumably based on information about the weather, or maybe a sensor that measures the light level in the room, or?
In either case, I would suggest that waking up once a minute to check the conditions and decide whether the blinds should be open or closed for the next minute, must be more than good enough.
No, your not missing the point at all. That could very well be a viable option, and would not require the receiver to be active 24/7. It would require 1,440 transmits/day to poll openhab for status. I’m not sure from a power usage how much better this is, but I would imagine it would be better than continuously running.
The downside to this is if you wanted to make a manual change, it would not be immediate. It could take up to a minute, or whatever you set your polling period to.
I would be interested in checking this out to see if/how this would work in actuality. I’m currently using nrf24 modules for xcvrs, and would likely test with those.
Did you read my post? If the nrf24s have a sleep mode you could experiment with the duty cycle of the receiving radio rather than polling which would give you a better response time.
I did read it, but haven’t experimented with the radio sleep modes at all yet. I only have a vague understanding of how it works, or even how to implement it. I know it supports it - that’s about it. As I understand, sleep mode doesn’t support wake up from an rf signal. I’ll have to read up more on the capabilities of the nrf24 and rfm69
The idea of duty cycling isn’t to wake on rf signal (that’s an interrupt). The idea is the radio willingly goes to sleep for a set period of time and then wakes up and checks if there are any messages to receive, going back to sleep afterwards.
I’m also working on something very similar but haven’t got far with the radio communication yet. It’s clear that WiFi is not the answer, it has to be 433 MHz type of radio communication. There are definitely precedents for getting this to work.
I’m hoping to solve the battery life issue with a cca 8 x 12 cm solar panel recharging the batteries during the day - since blinds are always in windows. This is more important for my application which is actually raising and lowering the blind and a lot of torque is needed.
I’m not saying this is the way you should implement it (I’m a ‘wired’ guy, myself), but you maybe have heard of the ESP8266. It’s a very, very low-cost microcontroller with integrated Wifi. Basically, it supports deep sleep and so on, and can remain ‘active’ while using very little power. Apparently they can go for a year on a LiPo cell (don’t remember the specs of the cell, though).
I recently bought one just to tinker with the technology (Wifi+microcontroller under 10 Euros (12 Dollars) sounded too good to be true). I’m not sure about battery life, but power draw is REALLY low, Wifi connectivity is fast, reliable and you can even use the Arduino IDE (with some 3rd party libraries) to write code for the device.
Maybe worth looking into, and almost worth buying even if it doesn’t work out for that specific project…
Dont know if you talking about blinds or shutters. With blinds you have daylight all the day, why not using small solarpanel to refill the batteries. With shutters you have to calculate the time for refilling, depending if you close the shutters during the day.
I was hoping to do this on my 2" Faux wood blinds. I have a ton of blinds
throughout my house, so I’d like to keep the cost per blind as low as
possible. Solar panels are doable, but I have yet to figure out the best
method for having the blinds respond to commands. I have not spent any
time on this in several months, but when I come back to it I’ll be sure to
post my results, unless someone beats me to it.
Just a quick thought: Maybe using solar charged power banks would be a solution to your energy problem. Easily buyable at your favorite china dealer. Charging is already implemented, Nice 5V output is also already in there. Finally you got enough juice to actuate the servo.
I’m new to all of this, so if is not even close to doable then forgive me N00Bness. My next project is blinds just like what you are doing. but I might just run wires through my attic, as it’s not too difficult.
building on CeeCee idea, maybe a flexible solar panel that opens when the shade opens, in a way that is not noticeable (have a few ideas).
or wait for the solar panel window films and add a couple of those (lol)
then connect that to a charger and lipoly or life battery.
here are some ideas. just put some random stuff together, to give you more ideas man. i love brainstorming, and helping out.
please keep us informed on what you decide. might help us out. THANKS!
I’m glad to see some traffic on this thread, because I think it has real potential for many to use.
Here are a couple key requirements to me, that others may or may not agree are important:
Low overall cost per blind
Runs on stored power (i.e. batteries)
Self-contained within blinds
There may be more that I’m overlooking, but we could add to those. Maybe if we can put together a list of requirements that are pretty agreeable, we can divvy up the work and have the experts collaborate to come up with a design that others can benefit from. Any other things to consider are welcomed.
Personally, I’m using the Home Decorators Collection 2” faux wood blinds purchased from Home Depot. Lowe’s carries another brand that is very similar, but I’m not sure of the internals and how easily the servo can connect in those. The above Home Depot blinds are PERFECT for a very easy setup.
Personally, I would not be opposed to having a solar panel on each window, but I admittedly don’t know much about designing that. I do believe you would require some type of charge controller to prevent the batteries from overcharging. Not to mention it would add cost per blind.
I think the other option would be to have each blind “check in” to the controller on a regular basis. This would make manual changes not happen instantly, but would significantly cut down on battery usage instead of having the sensor’s receiver always powered up waiting for commands. There are some error checking parameters that I believe are built into the MySensors code that if a command is issued and not acknowledged, the command is repeated. This could enable only the receiver to be powered up every so often as opposed to having to transmit from the sensor back to the controller and waiting for a reply.
As in my last reply, I have not had much time to put into this, but it would be very nice to be able to implement a < $20 (or better yet < $10) solution per blind. I have a ton of blinds!
Depending on how deep you are into electronics, this might be a tough thing to crack. Unless you have a lot more sun than where I am, there’s no way you will be able to keep the radio on (rx) the whole time. (unless you want to put a rather large solar panel in your window, with battery backup or super cap for night time operation/cloudy days.)
The only way (well…) to get this to work is, as you are mentioning yourself, is to let the unit power up periodically, and quickly poll a server for jobs, then go to sleep again.
But this needs good coverage over the whole house, and lots of finetuning/tweaking. I’m not saying it cant be done, because it certainly can with a little time and effort. Since you will have a lot of them, I presume you don’t want to change batteries every day or two…
It would be practical to use a zwave solution, but I don’t think there are any battery devices for doing generic control out there(?). And probably too expensive in the end anyway. Unfortunately the devkit for zwave is too costly for one off project.
Is there no suggestions on mysensors.org? There are a few blinds solutions there. But I don’t think they are battery operated though, but there might be some solution for generic (battery/wireless) control.
Is it impossible to run very (very!) thin wires to each window?
I’m thinking the same thing, but I’m not informed enough about solar to
make that call at this time. What I do think would be pretty easy would be
to have the blind sensor check in every 5 minutes and last a pretty long
time.
I’d love to know how they do it on commercial blinds with a remote, because
most are powered by just a few AA batteries. They just cost ~$300 each!
Can you link to one that product you describe? I looked at the Somfy solution, and it is a rather long battery. I’m guessing that they has the radio on all the time, or a couple of times each second. But I think their radio is much more power efficient than a full high speed radio, since they only need to receive a short message similar to a IR transmission. I could be wrong though, I haven’t looked into the solution in detail.
Only new here but I can tell you that I went to my local electronics shop and bought a few (cheap) 12v gearbox motors (70rpm - http://www.jaycar.com.au/12v-dc-reversible-gearhead-motors-70rpm/p/YG2732), and made a simple rubber shim to connect them to the turning portion of the venitian blinds, the bit that rotates to make the blinds open and close (yes, I removed the manual bit - I dont need it any more). I plastic-glued them inside of the guts of the blinds and you cant see them at all…
Mine are hardwired directly to a set of PWM H-Bridge’s (because multipley blinds acting at the same time and I can control them seperatly this way).
I can use an ARDUINO to tell my H-Bridge which direction and how long to open/close the blinds, and I have an IRblaster setup to recieve the open/close from the TV remote… this is where openhap will be taking over in the future… (why I am here)…
It was a quick “hack”, that I have now had in for 3 years - but very effective. The blinds were cheap and the solution was cheap.
If I was to do it again, I would use RC servo motors as some of those run 5V - and I woudnt have to use the Hbridges (arduino can drive servos directly) then I would put a ARDUINO Nano in each blind with an 422Mhz remote so I can control each one without having to hard wire. similar to what your trying to do.
you could do the same thing and have them run on 9V batteries… they dont have to go fast, they just need to open and close… the battery would last ages!
anyway hope that feeds your ideas… If I can find the photos of how I did it I will post them… hopefully it helps you
Mike
I started off wanting cheap and no cables (so battery powered) so bought an ezwand (http://remotewindowblinds.com/). Using it with an RM2, it works, although being analogue there’s no exact control of positions.
Since you will have a lot of them, I presume you don’t want to change batteries every day or two…