Cheap BlueTooth Buttons and Linux | Hacker News Reader

Cheap BlueTooth Buttons and Linux

shkspr.mobi

113 pointsedent29 comments

> After a few minutes of idleness, the device goes to sleep. Pressing any button wakes it up and repairs the connection - but then another button press is required to send a key press. The pairing process only takes a couple of seconds, so it's not quite instant.

That may be the biggest gripe people have with bluetooth input devices. That once asleep, it takes noticeable time before it wakes back up and during that time all inputs are /dev/null-ed.

The Flic button (https://flic.io/) does not have that problem.

Flic uses BLE (Bluetooth 4).

It also costs 10x as much as the regular BT buttons. Can't wait for BLE to drop to mass market prices.

When the ESP8266 successor, the ESP32 comes out you'll be set: https://www.sparkfun.com/news/2017

For now, you can always buy your own bluetooth LE modules and attach them to a small microcontroller, for buttons, you could make your own wall buttons with nice enclosures or go the ridiculous route: https://www.adafruit.com/products/1185

I made a WiFi button for pretty much the same purpose:

https://www.stavros.io/posts/emergency-food-button/

A bit latent, but doesn't require a second press.

That's brilliant! I'd never have thought of designing my own hardware. Kudos

Me neither, but I gave it a shot and it turns out it's super super fun (it's now one of my favorite hobbies, I'm redesigning this right now: https://github.com/skorokithakis/esplights).

I definitely recommend it, KiCad is great, the people at #kicad are great, and the people at https://gitter.im/esp8266/Arduino have taught me most the little I know now. I can't urge you enough to try it.

They will. For our smart socket the chips approach one dollar. Won't take long..

BLE "tags"[1] cost ~$2 shipped and seem to send a notification every time their button is pressed. I'm not sure if they perform well in the case of powering down and then back up, though. It seems like they might need a button press to allow a host to reconnect to them, which would present the same problem as in the article. And they have awfully annoying beepers in them that beep with every button press, and beep multiple times before powering down.

1: https://github.com/sylvek/itracing2/issues/5

I have a Logitech K380 keyboard and it doesn't do that and I love it. It's the most magical thing in the world. It's unfortunate that the keys are round and kind of suck to type on.

I have a Microsoft Sculpt Bluetooth keyboard.

On Linux, it does this.

On OSX, however, it still takes a few seconds to wake up, but the keystrokes typed while 'waking up' do make it through to the screen in the right place.

I keep meaning to dig into the Linux Bluetooth stack to see if those initial keystrokes can be salvaged. I guess they're sent in a burst once the keyboard realises 'yeah, I'm being typed at', but Linux seems to ignore them for some reason.

If you want a nice BLE button, I can recommend these:

http://www.alibaba.com/product-detail/Bluetooth-key-finder-n...

Alibaba is confusing and shit as always, but they're manufactured by Shenzhen Minew Technologies Co., Ltd. - minewtech.com and the model number is "F1".

Inside it is an nRF51822, a button, an LED and a buzzer (which isn't very loud sadly). The key thing is that the nRF51822 is fully documented (so you can make your own radio protocols if you want - it also supports BLE), and is supported by mBed so it is really easy to program.

It's nice that it's BlueTooth and a small button but the same effect, but instant, can be achieved with a 434 MHz receiver [0] and any remote that can switch wireless powerplugs like [1]. The sending units (that can be addressed using GPIO pins) are very small [2] so no doubt there are small button varieties.

[0] https://www.sparkfun.com/products/10532

[1] https://www.google.nl/search?q=impul+electro&ie=utf-8&oe=utf...

[2] http://www.watterott.com/de/RF-Link-Sender-434MHz

neat, but I was kinda hoping for a hardware hack, or looking at the contents of the eeprom. Maybe I'll have to grab one myself.

Do it! They're a couple of quid each, so well worth experimenting with.

is there anything on the other side of the PCB? it's nice that there are all those labeled test points on top, wonder what the UART interface is like.

Nothing on the other side, sadly.

Last night, I was playing with a little Bluetooth tag the host of a hackathon gave out to all the attendees. I threw some pictures up here:

https://sidnicio.us/btle-tag.html

It supports BTLE, so you can talk to it without any pairing and leave it turned on without (supposedly) using much power. If your computer has the right hardware, it should be incredibly easy to write a program which listens for button presses. I used an iOS app called LightBlue to poke at it. The app lets you scan for BTLE devices and read/write/subscribe to properties.

I love the idea of dedicated hardware controls for computers. I thought of making this a work-in-progress commit button, which quickly makes a “WIP” commit to your current project. Maybe other people have even cooler ideas?

Wonder if not British reader will get "half-inched" :)

I was wondering about that one. Any chance you can translate?

http://www.cockneyrhymingslang.co.uk/slang/half_inch

Half inched - pinched - stolen.

I use one of these as an input device with my smartphone in a stereo viewer. I like it better than the Google Cardboard bumper or even a full gamepad.

Thanks for this! I think I'll grab one and play around with it. If you created a github repo with the python script, I could star it, or post anything I find in the eeprom etc.

> Selfie sticks - like most modern inventions - are utter tosh.

Proceeds to hack a Bluetooth button so he can turn on his lights...

Yeah but one is an exercise in thought and engineering while the other is typically an exercise in vapidity and narcicissim.

What the OP learns about this BT button could transfer to him building his own that works better, then coming up with an derivative that has market appeal and now they're employing people and engaging the market. It probably won't happen but that person with a selfie stick is NEVER doing anything for society with that selfie stick.

It's not about the importance of the task, in my opinion, but the mindfulness of the task that makes something worth while.

I too look down on selfie sticks, but primarily because they've become such a pain in the ass- go to a crowded tourist spot (especially an international tourist spot) and it's been made worse by now having to weave through a mass of humanity and trying not to get hit in the face by a long aluminum stick.

I also think the self centered nature of them is annoying as well. Seeing them kind of reminds me of something out of Idiocracy.

How is taking photos of yourself vapid? For most people, that's the only kind of photographs worth taking. They're a documentary of your life.

I say typically as I pictured the teenager taking 30 selfie snaps a day for their Snapchat timeline. Or the bro grabbing a quick gym shot for Instagram. To be fair, I should have said stereotypically.

The selfies where you're capturing a moment or something interesting (like a tourist spot) aren't so vapid, but when that tourist destination is filled to the brim with people and a very large percentage have 3-5 foot aluminum poles swinging around it really sucks.

There's still a sense of narcicissim to it when you're streaming your vacation to your Facbook/Snapchat/Instagram feeds real time. I get putting a couple shots up at the end of the night or trip, but I swear I could create an itinerary for some people's vacation down to the half hour.

Whatever happened to gathering the group around and getting someone to snap the shot for you? I don't take a lot of photos on vacation because I like to really soak it all in- and all I take is my iPhone as my camera. So I'll get some goofy shots, some shots with the wife, and maybe some really interesting or beautiful things I just really want to be able to look at again. I might take only 20 photos in a week long trip.

FWIW I should probably have reread what I wrote since I guess it comes off as making fun of him for playing around with a bluetooth button. Oh well live and learn.

I was making more of a joke about the fact that he bought $40 lifx bulbs that require you to update the firmware for them for the privilege of shutting your lights on and off. I think author of the post would agree that that is also utter tosh, regardless of the use he gets out of it.

Reply on news.ycombinator.com