How do you make a remote bluetooth command pushbutton that integrates with Raspberry Pi and smartphones?

I'm looking to create a simple, small remote control with a single command pushbutton that transmits over bluetooth. I want to be able to integrate this function with a smartphone or a Raspberry Pi Zero W, similar to a remote camera shutter button that could fit into a rubber/silicon type ring/sleeve attachment to fit around a water bottle, for example. I've got very limited experience in this so any help would be greatly appreciated! I've found some similar tutorials but nothing specifically for what I'm looking for in a small envelope. Thanks!

Question by sam r wilson  

Tesla's human powered helicopter possible?

I know he was a smart dude and he went out of his way to patent this. Was it ever built? Could it be built and work? I don't understand the propulsion system. Is it like a bicycle or is it something else? I need one of these bad to deliver free fruit to people everywhere. My car keeps getting stuff in traffic. I don't know where all these cars think they're going, but I've got places to be and the road just isn't cutting it anymore for me. And dangit the uploader isn't working. Here's a link to the patent description and images: Well, not a link. A  URL. I dont know how to do a hyperlink without the- nevermind. sort of figured it out. Click below:

Topic by avocadostains  

Could there be 'test tube adults'?

I always wondered, If there can be 'test tube babies', could the placenta possibly be delivered whole and alive and the baby continue to develop outside the womb but in a womb like environment. or possibly in the womb of another animal.  I'm wondering, could there be 'test tube adults.' who come into this world fully grown? What feeds the placenta? Amniotic fluid? Blood?

Question by avocadostains  

Delay off Circuit 12V - 3A? Mosfet or Relay?

Hi all, I want to make a delay off circuit 12V - 3A. When the switch is ON, the circuit will operate during 1 to 3 minutes, and when the switch is OFF, the circuit should work during 0.5 second before it turns off. I made a delay off circuit using NE555 and a mechanical relay and it works. However, I need to make a smaller, cheaper and more efficient circuit. I need your help and your advice to gain knowledge and improve my circuit. Thank you.

Question by plantin110    |  last reply

I need a 3D printer for under $300!!!

The 3D printer must be under $300 including materials, electronics, motors etc. It must also run on an arduino mega 2560 which is not included in the cost. It must print at least 30cmx30cmx30cm and a maximum of 45cmx45cmx45cm. It must be able to run on a mac!!!!! it can be made of anything but I don't have a CNC router or laser cutter. I live in australia so sadly we don't have a TechShop!!! The printer must be able to print in high quality! I am only 12 years old!!!!

Question by Harry Park    |  last reply

Anyone know how to make an alarm that knows if my dog is being stolen?

I live in an area where people steal dogs out of our yards. I want to build an alarm that does two things: it allows the dog to roam in an area like my yard without going off and if he's taken, it goes off. The second part is that it sends a signal so I could track it on an app and help the cops get my dog back. There's got to be a simple way to make one with a Rasberry Pi or Arduino. I've never used either and want to learn, probably with the Pi. The dog would have to wear it on his collar naturally. Any help is greatly appreciated. I'm brand new to Instructables so you've probably seen something like this before. Please help. I'd love to make them for Christmas for several family and friends through our church. Thanks, Mike 

Question by Ghostrider13    |  last reply

How can I convert 9 volts DC to 1 millivolt DC?

I need to be able to convert 9 volts to 1 millivolt. Is there a schematic/circuit that can do this? If so, could you please provide one or details on how to make one? Thank you!!!

Question by vak52    |  last reply

How should I recharge a 7.4V battery? Answered

I have a 7.4V rechargeable battery and I'm wondering what voltage I should be charging it with. would 9V work? Are there any general guidelines for recharging batteries? Specs: 7.4V 1400 mAh Lithium-ion Was originally used in a NXT LEGO robot. Thanks! Ryan

Question by jensenr30    |  last reply

Need Free altoids Tins!!!!!!

I need some altoids tins for electronic projects. I live in Australia and altoids are not sold here. I will pay shipping if under $15USD.

Topic by Harry Park    |  last reply

Is It OK For Me To Use This Transformer?? Answered

I have a few questions about my transformer that I scavenged from an audio amplifier. I assume this transformer was used to drive big speakers. This bad-boy weighs in at eight pounds and is pictured below. The coil has a resistance of 2.2 Ohms. Is that normal? The Impedance of the transformer @ 60Hz will be higher that 2.2 Ohms, right? The transformer was wired into the wall outlet (120V AC) with only a #102 (1000pf) ceramic capacitor and a 125V-6.3A fuse in series. that means that the power comes from the wall goes through a fuse, a transformer, a ceramic capacitor, and then back into the wall. The fuse was burnt-out so I am bypassing it for now. I fully intend to get one asap. The #102 ceramic capacitor either isn't working or limits the voltage too much so I am bypassing that as well. What is this capacitor used for? Some of the voltage levels that I am measuring from the outputs of the transformer are as follows: 5v, 30v, 40v, 60v, 80v, and possibly a 100v measurement. There are a lot of outputs on this transformer so it is hard to remember all of the voltage levels. Is there anyway to tell how many amperes I can safely draw from this transformer? (I have no datasheet and cannot find one) Thank you for taking the time to read my plight! I would really appreciate a reply! Thanks!

Question by jensenr30    |  last reply

Germinating Apple Seeds? Answered

Has anyone here ever successfully germinated seeds from store-bought apples? if yes, how should I proceed?

Question by jensenr30    |  last reply

Chords With An Arduino Microcontroller?

Does anyone have any idea as to how I could make more than just one tone with the Arduino Uno? I would like to make chords. I had an idea that you could make octaves with a binary counter that would half the frequency, but you still only get one key at a time (i.e. A, G#, Db, etc...)

Question by jensenr30    |  last reply

pike fishing lures? Answered

Hello i was wondering what kind of lures to catch pike. like cheaper end ones "wal-mart" kind. its spring time i want to catch a big one this year. please post picture or links. thank you!!!

Question by joelr97  

value of my coin? Answered

Hi i have a 1941 walking liberty half dollar. I have been trying to figure out how much its worth for years. I found it with my metal detector so it has some wear on it.

Question by joelr97  

my RTL memory circuit is an oscillator? please help! Answered

Today I soldered together a "D-latch" one bit memory circuit comprised entirely of resistors and transistors. If someone asks me about the schematic, I'll post it. The weird thing about my RTL (resistor transistor logic) memory circuit is that it also works as an oscillator that short circuits my power supply. There is also a slight delay between when i try to set my D-latch's memory state, and when it actually happens.  I have an educated guess that the delay in state change is caused by whatever bizarre mistake caused the oscillation within the circuit. does anyone know of any resistor transistor timer circuits on the web? that may help quite a bit. (lol. EPIC memory pun) the picture above is my device. the oscillation is around 1.2 Hertz. it occurs when the D (data) input of my memory circuit is high. as you can see, this is really confounding me. please help with a comment!

Question by jensenr30    |  last reply

CMOS vs TTL? Which Is Better? Answered

What are the main differences between CMOS (Complementary Metal-Oxide-Semiconductor) and TTL (Transistor-Transistor-Logic). The things I want to know: Which type do you use? Which kind do you prefer? Which type do today's computers use? Are CMOS and TTL compatible? These are the few things I know about them: CMOS ICs (overall) will draw less current compared to TTL CMOS are less picky in regard to their voltage supply. It seems like most people like CMOS more than TTL. Thanks! Comments, answers, and everything else is appreciated!

Question by jensenr30    |  last reply

Why can't I add my "Create a NOR Gate" instructable to a guide that I'm making? Answered

I am able to add my "Easy AM Transmitter" project to the guide I'm working on but not my other instructable, "Create a NOR gate". Does anyone have any ideas as to why this is happening??

Question by jensenr30    |  last reply

There is no delete button on my unpublished instructable! How can I delete it? Answered

As you can see, there is no delete button in sight! what should i do?

Question by jensenr30    |  last reply

Do Nickel-Metal Hydride batteries make a quiet popping sound when recharging? Answered

          I am recharging my Ni-MH batteries today (Wii-motes eat them up fast!) and I was wondering if it is normal to hear a quiet popping noise coming from the batteries? it sounds like tiny bubbles popping--very similar to the sound carbonated drinks make after being poured out of the original container.         I believe this noise is a result of the reversing chemical reaction being created inside the battery. the batteries shown below are my exact brand and model.         Is anyone else experiencing this phenomenon? If so, do you think it is normal? Leave your thoughts, comments, and otherwise below!      =D

Question by jensenr30    |  last reply


Where can i get LEDs?!?!?!?!?! i see all these awsome projects but i cant find LEDs. please recomend a american store or send me a link. thx!!!!!!!!!!

Topic by laxfreak