check out the June 2016 article for that full
story). So, we used the Canipede robot
control module and 2CAN Ethernet gateway,
and created a wireless network for the bot
with an onboard travel router.
We were able to control the bot using
the uCANDrive app on our smartphones, so
it almost sounds like we’ve already achieved
what we’ve set out to do this time. The bot
may have had a Wi-Fi connection, but it
wasn’t like what we envisioned for
something connected to the Internet. We
had to follow the bot to keep in range of the
network, and the dodgy travel router did not
provide a reliable signal. Our vision of high
tech Wi-Fi control conjures up images of
driving as slick and self-assured as Johnny 5
escaping from NOVA in “Short Circuit,” and
not driving as jerky and unreliable as Johnny
5 after he’s accosted by those hooligans in “Short Circuit 2.”
So, we researched our options for connecting a robot
to the Internet and turning our smartphones into robot
controllers. We wanted something that could work with our
phones because smartphones seem like they could be the
ideal controller for a robot — they’re ubiquitous, and there
would be no need for tracking down a radio for your bot.
Would a smartphone touchscreen provide the sensitivity
needed for robot control? Or, is the Io T destined to exclude
It only took a quick search to find exactly the
technology we were looking for: the ESP8266. The ESP8266
is a Wi-Fi chip with an integrated TCP/IP protocol stack that
can give any microcontroller access to a Wi-Fi network.
That’s pretty rad. The ESP8266 was introduced by the
Chinese manufacturer, Espressif just a few years ago, and
the chip really took off with Western tinkerers with the
introduction of the ESP-01 module from third party
manufacturer, AI-Thinker in 2014. The most striking things
about these ESP modules are their size and affordability.
They are about the size of a movie ticket stub (albeit a long
rectangular one), and they can cost under $4. What a time
to be alive!
As with the Arduino and Raspberry Pi, a dedicated user
base has coalesced around the ESP8266. One of the great
features of such a vibrant user base is the development of
numerous accessories and hardware improvements on the
fairly minimalist ESP module. We found one such
improvement from one of our favorite sources of electronic
awesomeness: SparkFun. SparkFun’s ESP8266 Wi-Fi shield
combines the Wi-Fi connectivity of the ESP8266 chip with
the shape and familiar pin breakouts of the Arduino — all
for about $15. The Wi-Fi shield can even be used as a
stand-alone board, and users can load their own custom
code onto it using an FTDI breakout.
We, however, found that option a little risky. Your
custom code overwrites the AT-command firmware that
comes on the unit, and the custom code might not work
with the AT commands essential for connecting to Wi-Fi.
So, we planned to use the Wi-Fi shield as, well, a shield.
The Arduino Strikes Back
The Wi-Fi shield works on the 802.11 b/g/n standard
and the familiar R3 Arduino pin layout. The Wi-Fi shield
would be a perfect fit for our Arduino Uno, but before
connecting to the Internet there was some assembly
required. The SparkFun page on the Wi-Fi shield
recommends using the stackable headers, and that’s exactly
what we did.
Soldering on the stackable headers is quick work that
we completed in Robot Central one afternoon with
Twin brothers hack whatever’s put in front of them, then tell you about it.
SERVO 08.2016 55
SOLDERING UP THE WI-FI SHIELD.
STACKING THEWI-FI SHIELD ON ANARDUINO UNO.