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Show HN: Raspberry Pi garage door opener

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Re: Show HN: Raspberry Pi garage door opener

#111

Post by GordonS »

Ductapemaster wrote: post #104
kavalg wrote: post #47

Earlier quoted context omitted.

Not my experience with commodity SD card, power supply and stock settings of Raspbian. They must be using some "secret sauce" to make them run 6 years without outages. I would suspect some industrial grade SD card (SLC or at least AMLC), high quality power supply (e.g. UPS with surge protection) and also some way to limit writes on the SD-card.

Any disk-IO heavy application will brick a card in record time. I worked on a lot of Pi-based systems at my last job (long term time-lapse photography) and we learned quickly to: 1. Buy high quality SD cards 2. Remove as much disk-IO as possible, using an external USB stick for raw data storage, logs, swap, etc 3. If you really need to make it stable, make the OS read-only

You mentioned USB sticks, but I just assumed they used the same type of flash memory that SD cards use?

Aside from USB sticks, any ideas on alternative storage suitable for RPis (something small)? I know you can get eMMC modules that fit into the SD card slot, but I would have guessed they'd have the same issue with writes.

Re: Show HN: Raspberry Pi garage door opener

#112

Post by froh »

hjklmn wrote: post #108
buescher wrote: post #95

Earlier quoted context omitted.

Those are the industry requirements written by people with understanding of the hazards of running a garage door opener out of line-of-sight of the door. Read them carefully. There are reasons for each of them. Think hard about it. Remotes also operate differently than your wall button. Did you know that?

Those are industry requirements for garage door openers being sold/used. The project above is an open source prototype and by no means a product that consumers are expected to buy/use as is.

Does the project clearly state so? I think such lack of warning is the point here. Note that a warning should include an indication of consequences.

The current disclaimer in the readme just points to electric shock. Not to the wealth of known hazards from malfunctioning electric garage openers, referenced further up in the thread.

Re: Show HN: Raspberry Pi garage door opener

#113

Post by rtkwe »

hjklmn wrote: post #108
buescher wrote: post #95

Earlier quoted context omitted.

Those are the industry requirements written by people with understanding of the hazards of running a garage door opener out of line-of-sight of the door. Read them carefully. There are reasons for each of them. Think hard about it. Remotes also operate differently than your wall button. Did you know that?

Those are industry requirements for garage door openers being sold/used. The project above is an open source prototype and by no means a product that consumers are expected to buy/use as is.

It's usually good to at least look at the requirements to see what kind of problems can come up.

DIY projects get a load of leeway but this one is actively dangerous and missing really important safety features outside of the remote operation stuff in this thread. If OP is lucky it'll be the garage door instead of an arm or their car because there's no break beam or current monitoring so the motor will happily pin and crush someone unless it stalls out.

Re: Show HN: Raspberry Pi garage door opener

#114

Post by bonzini »

jstanley wrote: post #52
sgt wrote: post #51

Earlier quoted context omitted.

This is great. Question - why did you use the relays and not just the GPIO pins on the ESP to short circuit the contact on the remote for a brief moment?

You can't use GPIO pins to short 2 contacts together. The best you can do is apply voltage to the contacts (which might be workable, depending on how the remote is designed). To short the contacts you need either a relay or a transistor.

Assuming one of the contacts is connected to either ground or Vcc, one thing you can do is connect a GPIO pin to the other contact. Then when the GPIO is made an input the switch is "open", to close it you first write the value the other contact was connected to, and then you make the GPIO an output. Whether this works depends on the current that is sinked by the remote. This was my plan initially but then I went with the relays.

Re: Show HN: Raspberry Pi garage door opener

#115

Post by airbreather »

kavalg wrote: post #47
GordonS wrote: post #36

Earlier quoted context omitted.

Not sure this actually happens. In practice. 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 gl…

Not my experience with commodity SD card, power supply and stock settings of Raspbian. They must be using some "secret sauce" to make them run 6 years without outages. I would suspect some industrial grade SD card (SLC or at least AMLC), high quality power supply (e.g. UPS with surge protection) and also some way to limit writes on the SD-card.

Commodity SD cards - there's your problem. It's not a camera you need to buy industrial grade to get 0.5-1M write cycles.

Just bought industrial grade SD cards for Siemens PLCs the other day, almost $2k for 32 gig and due to certification for safety only good for ten years regardless of condition/use.

Equivelents spec cards without the magic S word on them are still around $800.

They are actually a different kind of memory used, so I guess not manufactured in same consumer number quantities.

I always liked the look of something like puppy Linux that loaded to ram, pretty sure most Linux variants allow this as an option, that would potentially make use of consumer grade palletable.

Re: Show HN: Raspberry Pi garage door opener

#117

Post by scurth »

I love these types of projects. It is not rocket science, nor anyhow complicated to solve and from security standpoint way better than any off the shelf solution. Think about it: you grant access to a random company, with people working there you do not know, security standards out of your control, and if they decide to change the product you simply have to deal with it.

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.

Re: Show HN: Raspberry Pi garage door opener

#118

Post by woutr_be »

soylentcola wrote: post #67
woutr_be wrote: post #22

Very cool project, I've been wanting to do something with my Raspberry Pi as well. 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.

If they use IR remotes, I imagine you could plug in a network connected Pi with a USB IR blaster next to each AC unit. Then stick the IR emitter LED on the little window where the IR receiver is on the AC unit. 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…

I looked into the IR blasters before, was wondering if they're strong enough to transmit to multiple targets.

I've previously written a Telegram bot, so was thinking to reuse some of that.

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