Your robotic problems solved here.
To post comments on this article and find any associated files and/or
downloads, go to www.servomagazine.com/index.php/magazine/issue/2017/08.
article link. (SparkFun hosts an older Beta version 1.0 at
Car.apk which is not as user friendly.) The MagicCar app is
by Chinese Arexx/DAGU but their email reply to my request
for information didn’t say much about it:
Hi Eric, DAGU made this Magic Car app before, and
this app was used on Magician Chassis.
This [D2-6] robot kit is made by the other company,
not DAGU. Best regards, Dagu Hi-Tech Electronic Co., LTD.
Even DAGU’s former lead designer and chief mad
scientist, Russell C (a.k.a., oddbot) didn’t have much to add.
So, this app appears to be orphaned in Beta form, but
thankfully it still works great with the stock robot.
Speed and direction values are constantly displayed at
the top left of the screen. The D, A, G, and U letters at the
bottom right are buttons which send unique codes via
Bluetooth. Although not used by the stock microcontroller,
we can use these in our own code for other purposes.
Banggood’s zipped folder includes information on
reprogramming the 16-pin STC15W201S microprocessor for
anyone who wants to accept that challenge.
After “mastering” the stock robot, I replaced the STC
chip with a more familiar PICAXE 20M2 and expanded it by
adding an IR input and a beeper output. The robot’s PCB
chassis includes male headers (Figure 3) which allow direct
access to each pin, so you can DIY your own plug-in
module using most any controller. This bot was meant for
This robot uses a single 3.7V 14500 Lithium-Ion battery
(not included). It’s roughly AA sized; barely longer. Four
batteries and a charger are just $5
( www.ebay.com/itm/162285518252), but don’t be
mislead by fantastic capacity claims of 2,500 mAh or more.
Most awesome-sounding Trustfire, Ultrafire, and GTF brand
cells are under 400 mAh, so they won’t last very long in
Grab yourself an eBay $3 ‘ZB2L3’ battery capacity
tester to know what you’re getting (review at
battery-tester.html). I have tested many batteries, and my
highest capacity types are old generic blue batteries
claiming a modest 1,200 mAh, which actually deliver over
400 mAh. Caveat emptor! You may prefer to substitute a
small 3.7V LiPo if you have one and the matching battery
Enough talk! Let’s fire up the soldering iron and build a
robot. Kit contents are shown in Figure 4 and the
schematic and BOM in Figure 5. The build took me about
two hours following Banggood’s English assembly
SERVO 08.2017 9