
Cheap BlueTooth Buttons and Linux - edent
https://shkspr.mobi/blog/2016/02/cheap-bluetooth-buttons-and-linux/
======
digi_owl
> 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.

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

~~~
edent
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.

~~~
jc4p
When the ESP8266 successor, the ESP32 comes out you'll be set:
[https://www.sparkfun.com/news/2017](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](https://www.adafruit.com/products/1185)

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

[https://www.stavros.io/posts/emergency-food-
button/](https://www.stavros.io/posts/emergency-food-button/)

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

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

~~~
StavrosK
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](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](https://gitter.im/esp8266/Arduino) have
taught me most the little I know now. I can't urge you enough to try it.

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

[http://www.alibaba.com/product-detail/Bluetooth-key-
finder-n...](http://www.alibaba.com/product-detail/Bluetooth-key-finder-
nRF51822-chipset-Android_60339669204.html?spm=a2700.7724857.29.55.FeHkKk)

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.

------
teekert
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](https://www.sparkfun.com/products/10532)

[1]
[https://www.google.nl/search?q=impul+electro&ie=utf-8&oe=utf...](https://www.google.nl/search?q=impul+electro&ie=utf-8&oe=utf-8&gws_rd=cr&ei=lfDIVsfrCsixaZzsiUg#q=impuls+electro+remote&tbm=shop)

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

------
Palomides
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.

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

~~~
Palomides
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.

~~~
edent
Nothing on the other side, sadly.

------
Sidnicious
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](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?

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

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

~~~
edent
[http://www.cockneyrhymingslang.co.uk/slang/half_inch](http://www.cockneyrhymingslang.co.uk/slang/half_inch)

------
moron4hire
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.

------
sounds
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.

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

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

~~~
manyxcxi
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.

~~~
StavrosK
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.

~~~
manyxcxi
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.

