Here's the CPSC page on garage door openers: https://www.cpsc.gov/Regulations-Laws--Standards/Voluntary-S...
The pdf "Update of Automatic Garage Door and Garage Door Openers Entrapment Incidents. October 7, 2003" is a good introduction to the real, not internet-smart-guy-hypothetical, hazards of automatic door operation. It includes a summary of every entrapment incident found by the CPSC from 1982-2003.
The UL standard for openers UL325 is incorporated more or less verbatim into the mandatory standard 16 CFR Part 1211: https://www.law.cornell.edu/cfr/text/16/part-1211/subpart-A Have fun. This is the standard that an opener that retails for $99 on sale in the US has been engineered to meet. European and other international standards differ in particulars but are quite similar.
No, you will not accidentally meet real-world safety standards with your project by dint of your sterling virtue, high intelligence, wisdom in the ways of the world, and impeccable engineering skills. Nor will you do so by adding a couple more features. Safety is the result of deliberate processes.
This is project taking complete control over the motor that opens and closes the door and NOT using the simple "throw a relay on the door opener" trick that you usually see (ex: https://cdn.instructables.com/F9V/T9JH/I9YBZHM7/F9VT9JHI9YBZ...).
This project is unnecessarily dangerous for such a simple application.
Would you feel encouraged or inspired if someone said this to you?
For example, instead of saying the quote above, you could have as easily said “I think this garage door opener project has a lot of opportunity for improvement”.
Mindset goes a long way, and it might just help make a friend or two along the way.
This is nuts.
This is unnecessary condescending snark that I hope we see less of on HN. Everyone should be open to criticism, but how does that encourage the inventor?
What makes you so sure?? I see people using such "experimental" devices all the time. Unless you tell someone explicitly why it's a bad idea they won't know.
For people that are interested in raspberry pi projects. I compiled a list, mostly for myself, but if it is semi-useful for anyone else, I'd consider that a win. I scoured HN and searched on YouTube, Google and thought of my own ideas to find the rpi projects that fascinated me.
https://docs.google.com/document/d/1xT6-vN4sFnRLMOdj9wC4_ESW...
I'll put this project on there as well under the category "smart home". While the concerns are justified, such as insurance issues and fire hazards, I find it a cool use of what one can do with cheap hardware.
Although I've grown cautious of products like Shelly which use Wifi as they will become obsolete once their Wifi security protocol becomes broken (like WEP en WPA). But then again the same probably goes for more expensive Zigbee and Zwave devices.
I'm a big fan of IOT and home automation, with one exception: door locks. I wouldn't trust any electronic device with my door lock. There's just so much more that can go wrong, both from a technical and a security standpoint. Also, electronic door locks aren't THAT more convenient than my physical house key.
I can almost guarantee you that you will sit in your car and scream bloody murder because the WIFI ist not connecting.
My products had to work with a lot of other networks around and were built on a Model 3 B, maybe it has improved since then.
Sadly I can't point you into the direction of solutions because we just switched to Ethernet.
I.e. clone an additional remote, then integrate with the buttons from a micro-controller to open/close. In addition, have some kind of way of detecting whether the door is open or closed, so I suppose the remote can be placed near the motor.
That way you can also easily integrate into your house's alarm system later on if need be, as it's most likely linked to your remote.
https://www.heyraviteja.com/post/weekend-projects/open-garag...
I did a similar solution a while ago, documented all the steps to replicate such setup: https://www.sascha-curth.de/projekte/004_Garagentor.html
I wrote it in german, but chrome/google translate is tested for English, Spanish and Portuguese. And comments/remarks are welcome via github issues.
ETA: by push buttons, I mean the "normal" garage door buttons that would open and close the door (typically on a wall in the garage.) these typically use some low power, e.g. 12-20V. And the safeties the manufacturer would have built in would still work as it'd be as if you were pressing the manufacturer's open/close button, but remotely.
Features:
- Web interface with multiple user accounts. - React/Material UI front end. - NodeJS backend with registration/login flows.
A friend works at an oil company, and they have dozens of rpis deployed on offshore rigs, and in land rigs in the middle east. They are working in pretty harsh conditions, with high salinity, sand in the air, high vibrations, very low temps, very high temps... and yet over the 6 years they have been running, not 1 has had a fault.
All use SD cards, and they haven't been glued in or secured in any way.
At this point, the RPi SD-card fault thing is becoming a meme.
The default rpi os writes to disk all the time, there is even syslog with periodic messages. I bet your oil company uses read-only root, or at least a customized os which does not log things unless it has to.
> Works locally only, via WLAN (it's a feature, not a bug!)
First of all, safeties. I was lucky to add my work to existing motorized garage doors - which already came with enough sensors, but since you are providing everything including the motor, these should be in from the very start, or in any accident you'd be held liable. Actually you may even be held liable if someone implements it from your github repo and then has an accident. I know you have a disclaimer, but I wouldn't rule out being sued.
You want a sensor which detects any anomalous power draw in the motor and immediately cuts off power. Something as simple as an ACS712 (follow guides for reading an inductive load though!) which is a couple bucks (or less if you buy a bucket from China). The motor may come with built in safeties if it's meant for a garage, but this is something I'd still consider.
You will want not only a sensor but also a couple emergency buttons on both sides of the door which instantly stop all movement. While you're there, activating a couple very visible flashing LEDs for a few seconds before you start any movement is also a good safety precaution. You have 2 relays which could due to a bug or other unexpected circumstance be energized at the same time - Depending on the motor this could cause a fire, or fry your relay board/Pi. I would use one relay with its NO contact going to the DOWN motor pin, and the NC going to the UP motor pin, and connect it in series with the other relay which cuts all power. This way it's not possible to energize both in any case (beware: even abruptly switching directions may ruin a motor - always cut power first, THEN toggle direction, THEN provide power again)
Happy to discuss a few more points if you feel like.
I mainly wanted to focus on turning my AC units on and off. I assume I'll need some sort of IR transmitter, and possibly a receiver to understand the signals the remote is sending.
Then it's just a matter of capturing the remote codes and setting up a way to remotely command a given Pi to send that pattern of pulses out of its IR emitter.
edit: I just did a quick search and Sparkfun sell WiFi IR blaster boards for $20. I'd imagine you could find cheaper ones on Aliexpress or other places where you typically find cheap electronics. This would probably be simpler to set up versus a Pi with less things to break since it's not booting a "full" general purpose OS.
That said, I do love adafruit and sparkfun for most purchases. My bank account doesn't, but I certainly do.
I've previously written a Telegram bot, so was thinking to reuse some of that.
Do you have a repo to share?
