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Ask HN: I want to learn how to prototype hardware. Where do I start?

108 points by allsystemsgo ↗ HN
I'm an iOS developer. I'm decent and have launched a couple of apps. With bluetooth LE and multipeer connectivity, I am very interested in learning about building a hardware device that pairs with my iPhone. Where can I go to learn more about prototyping?

37 comments

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lowglow
This wasn't too bad of a read:

http://www.amazon.com/Electrical-Engineering-101-Third-Editi...

But, if you're not talking discrete components and just want something to act as more of a controller, these boards are pretty friendly:

http://beagleboard.org/ (slightly more advanced embedded controller)

http://arduino.cc/ (pretty basic and awesome community)

http://www.raspberrypi.org/ (never played with one, but another popular option)

Read:

http://www.josetteorama.com/hardware-hacking-for-ios-program...

https://developer.apple.com/library/ios/featuredarticles/Ext...

You might want to come out to a SFHN event (https://www.facebook.com/groups/gosfhn/)

and Hackendo (http://hackendo.techendo.co/)

nickff
Pairing with an iPhone may be an issue for anything which is not an audio device. Apple requires all non-audio devices to have certain 'authentication' hardware which is only available to MFi-licensed developers. My information may be out of date, but please do check this out before you invest too much effort in this, as it may be very difficult. I went through MFi, but ended up developing for Android.
pugz
As you guessed, this information is out of date. Bluetooth LE hardware doesn't require MFi certification.
dakrisht
Developing BLE devices in iOS does not require any MFI licensing whatsoever.
jimmyswimmy
If you stick with digital hardware and interfaces, the materials everyone else has suggested are pretty useful. The TI MSP430 is a nice, cheap microcontroller and they offer something called a "Launchpad" which used to sell for $4.30. It is one of the workhorses of engineering design, and there are legions of websites about it.

Check out sparkfun.com for parts. They have lots of stuff and most of what they sell is accessible to the programmer type. They will have micros and BLE components and whatever else you may be interested in, and a bunch of nonprofessionals are using them and talking to each other about how to use them.

You can probably find an EE friend who would work with you if you're good. In that case you might be able to combine strengths and build something awesome. I know you want to prototype right now but if you get to a "good idea" you'll want someone who knows how to build hardware.

tptacek
The MSP430 Launchpads are great (we give them away at school events). Also, if you're interested in the MSP430 architecture, we've got one online for you to play with:

http://microcorruption.com

lytfyre
If your city has one, I've found Hackerspaces are a great way to find a community to learn from for this kind of thing.
siralonso
Other people have given you this advice already: Play around with an arduino for a while until you get comfortable with the hardware/software interface. If you're looking to incorporate sensors, get a few breakout boards from sparkfun (doesn't really matter what sensors) - one that you read as a voltage level from the ADC (analog to digital converter), and one that uses I2C, SPI, or another serial interface.

On the Bluetooth LE side, you CAN get a shield that sits on top of your Arduino, but it'll be bulky and power hungry. There's a company called Bluegiga that makes a BLE stack called the BLE112. Basically, it's an arduino and a BLE module in a package the size of a postage stamp. Not something you'd want to go into production with (doesn't get much below $15, regardless of quantity), but you can run it off of a coin cell battery for years, and it's got all the serial and analog interfaces you'd expect. You can get a breakout board for around $50 assembled - google 'ble112 breakout inmojo'.

Good luck! Build cool stuff.

Moto7451
My community college offers electronics courses. I've taken only one to date but I feel like it really helped me learn basic EE skills better than a book or online tutorial did. It also helps that they have a proper space setup to tinker and a budget to hand out basic components. My suggestion would be to see if your local CC does the same.
dschuler
I just got into Bluetooth LE as an Android developer. My school background is in embedded devices, so I wanted to see what's out there that I can program on the device side, and then connect to the phone.

There are two comparable offerings for Bluetooth LE chips (are there others? let me know): the Texas Instruments CC2541, and the Nordic Semi nRF51822. They can be purchased as development kits for $100, but the chips only cost $2-3 in larger quantities, so you could take something based on them to production without the cost being prohibitive.

I like the TI SensorTag (CC2541 based, $25). It comes with several sensors a coin cell battery, and iOS sample code, which is neat. http://www.ti.com/tool/cc2541dk-sensor

On the other hand, if you wanted to program the bluetooth device itself, the CC2541 isn't ideal. It's based on the 8-bit Intel 8051 micro controller, and TI's radio libraries only work with the very expensive and crappy IAR tool set. I bought their development kit for $100 before realizing that it's worthless without the $3000 IAR IDE :|

The Nordic Semi nRF51822 development kit is much better. Their chip is based on the ARM Cortex M0, so you get a tiny 32-bit processor. It comes with a programmable USB dongle that can be used right away, as well as a J-Link Lite CortexM-9, which can download code and do full GDB debugging on the device. You may need to be comfortable looking at schematics to figure out the other two included demo boards, however. http://www.nordicsemi.com/eng/Products/Bluetooth-R-low-energ...

If anyone knows of any other Bluetooth LE chip offerings, please let me know (I've read that Broadcom has 'announced' several chips, but I didn't see anything concrete that's shipping at the moment). The Bluegiga modules are too integrated for me, and too expensive to sprinkle them around the house for random sensing/controlling projects, but they may be easier to get started with as well.

vitovito
Remember, too, that another recent iOS 7 device can also run as a BTLE "client" and pair: that's how testing iBeacons works.

You can pick up an iPod Touch and write an app for it that uses the Touch's sensors to do what your custom hardware could do, to get further than you might if you had to start from hardware alone. Additionally, integrating new sensors into the Touch could be done more simply via the headphone jack using an Arduino: http://www.creativedistraction.com/demos/sensor-data-to-ipho... or using Project HiJack: http://web.eecs.umich.edu/~prabal/projects/hijack/

Once you've got a version using an iPod Touch and a custom sensor working, you'd have a complete test case and prototype to develop original hardware against.

dschuler
I wasn't aware of iBeacon, thanks for the tip!
jamesbritt
Do you (or anyone else) know a decent Bluetooth dongle that works on Windows 7 and will find and pair with LE devices?

I picked one up last week before a local hackfest, but in a room of a half-dozen BLE devices (one about 10 inches away) my laptop detected zero.

Could very well be I was doing something wrong but it seems there shouldn't have to be a whole lot to do after plugging it in and loading the drivers.

I think I just got the wrong thing. (It's a Kinivo BTD-400 Bluetooth 4.0 USB adapter.)

jwatte
Get an Arduino and a Bluetooth shield. <$100, let's you prototype away. Not the tiniest platform around, but still fits in a roomy pocket.
cellularmitosis
I am shocked that no one has recommended Contextual Electronics yet.

Dave Jones runs the best EE video blog on YouTube (EEVBlog), which also has an excellent forum associated with it. He co-hosts an EE podcast called the Amp Hour with Chris Gammell. Chris Gammell has been putting together a video course on learning how to make hardware for about 6 months now, and session 1A starts tomorrow (the 20th). I highly recommend you sign up (I did!). Check out some of his YouTube videos to see if you think you'd like it (search for Contextual Electronics).

michalu
You might be interested in "Fundamentals of Electrical Engineering" and related "Laboratory" course that start today on Coursera:

https://www.coursera.org/course/eefun

https://www.coursera.org/course/eefunlab

DennisP
It looks a little late to start the lab on this round. You have to order equipment, which takes a while to arrive. And you have to use Matlab, and they give you a license which only lasts until the course ends. They say Octave won't work.
michalu
Laboratory starts 27th and the kit arrived in 1 week, so there is a good chance. The videos were posted just today, I haven't started either. The kit costs more if you are from EU. If you start this week you should be alright. I don't plan to do anything until Friday anyway. Also laboratory is not required for first course so you can just jump in.
tostitos1979
Do a YouTube search on afrotechmods. The person who makes those videos is simply amazing. I have learned a tremendous amount.

I'd also recommend getting an Arduino and building projects with it.

ChrisGammell
Mentioned one other place here, but I'm running class called Contextual Electronics. You can choose your level of involvement. It covers PCB design and electronics design principles, leading up to building this: contextualelectronics.com/the-benchbudee/

So I suppose it depends about your definition of prototyping. If you want to do breadboarding stuff, a lot of the other suggestions on here are good: start with Fritzing -> Get an Arduino -> check out the tutorials from Adafruit/Sparkfun -> Dig in more with EEVblog and AfroTechMods

But then after that, if you want to design/build your own hardware, I recommend my program (duh) or checking out other PCB type stuff from Jeremy Blum using EAGLE (http://www.youtube.com/playlist?list=PL2419BD818ADB11E1) or Fedevel academy (http://www.fedevel.com/)

Good luck!