What Comes After Arduino?

Arduino is a great microncontroller package for entry-level
electronics tinkerers, but once you've got your sea legs,
cheaper DIY microcontrollers used to build anything from
grow-lights to irrigation systems are what you might reach
for next.

The Arduino platform is doing something amazing: bringing
hardware development to the masses. It's a sweet little
system, with a built-in hardware programmer, simplified
programming language, and lively user base that offers plenty
of sample code and assistance in the online forums. While
this fully assembled solution is a good way to get your feet
wet, there are a lot of good reasons to just buy an
off-the-shelf processor, make your own circuit board and
write in a low level language like C. It can be cheaper,
quicker and easier to debug. Here, check out some of the
projects I've made and how I pay for my hobby, as well as my
hardware setup.

What Do the Pros Use?

I'm not the only one who knows there are times to leave
Arduino behind. Adafruit Industries and Evil Mad Scientist
Laboratories are arguably the leaders of the DIY electronics
revolution. Look closely at their products and you will often
find a humble AVR micocontroller instead a full-blown Arduino.
I personally love a business card on which you can mount
a microcontroller and start developing firmware. You are
doing something right when you can sell your business card
for $4.75. Adafruit sells an inexpensive persistence of
vision kit for bike wheels that allows a single row of LEDs
to show images or spell out text. Using Arduino for such
a project would be overkill. Here are the two scenarios in
which I reach for an AVR rather than an Arduino.

To Save Money, Make Money

Arduinos generally go for $15 to $60 each. This is affordable
for one-off tinkering, but it doesn't scale well. I've built
10-unit runs of simple projects using raw microcontrollers
and custom circuit boards for 90 percent less than the price
of a single Arduino. Among them are a temperature display for
my veggie powered car, intelligent irrigation controllers for
the yard, even grow lights for plants that pulse LEDs.

These projects are also physically smaller than most Arduinos.
By shrinking the design and keeping costs low, it's easier to
sell your homemade invention and turn a profit. I've actually
been able to pay for my electronics habit by building a few
extra units and selling them online.
For Easy Debugging

Most Arduino users debug their code by sprinkling print
statements into the code then watching the output in a serial
terminal. This is an effective way to find out where the
software is misbehaving, but it's time consuming.
Professional hardware developers use in-circuit emulators
(ICE), which allow the user to see the values of each
variable and step through the code with a debugger as it
executes on the processor. These ICE-based systems massively
speed up hardware development time.