Your robotic problems solved here.
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loved or hated it (or they misunderstood it).
The fully-assembled PCB (printed circuit board) is the
chassis, so building it is just light mechanical assembly of
motors and wheels; 30-60 minutes max. The PCB has two
infrared (IR) obstacle sensors and the PIC16C505
microprocessor comes preprogrammed with several
routines (called “behaviors”) which may be selected using
the included TV-style remote control.
Behaviors include auto free-roam, seek light, avoid
light, and follow wall (a.k.a., maze solver). The robot can
also be driven directly using the remote control. No
programming is required, but there is an empty socket
which allows you to add an optional BASIC Stamp 2 chip if
you ever want to try programming. It’s a noteworthy
feature, but somewhat clunky as implemented since extra
SHIFTIN and SHIFTOUT commands are required for the
Stamp to talk to the PIC.
I programmed my TAB robot to chug around a figure 8
and flash its LEDs, as shown at https://www.youtube
.com/watch?v=PBe3EM5gLN0. The kit includes a vintage
CD-ROM which has the assembly manual and tons of
useful information, including a generous excerpt from
everyone’s favorite book, “Robot Builder’s Bonanza” by
guru Gordon McComb ( http://budgetrobotics.com). I
highly recommend that book for anyone interested in
robotics. With dozens of years of experience behind him,
McComb gives valuable info and insight on mechanical
construction as well as electronics (hardware) and software
You mentioned line followers and light seekers. I have
built both recently from kits. These are great choices since
they are interactive with lots of play value after assembly to
keep kids interested. There are amazingly inexpensive ($5
and up) line follower robot (LFR) kits from China; search on
Banggood or eBay for “D2-1 tracking smart car” (Figure
Various kits use AA batteries; some use AAAs —
whichever battery holder your supplier has. The Chinese-only instruction sheet is not difficult to figure out, and
there is an oval line course printed on the reverse side.
Soldering is required; being able to read a schematic
diagram and use a multimeter will help to verify resistor
The circuit board is well marked and easy to solder,
making the kit enjoyable to assemble. In fact, the PCB is
the chassis. My only caveat is that the PCB is one-sided; the
holes are not plated through. If you overheat the board,
the copper trace can come off. This is easiest to do where
the line sensors connect up front; you must solder two
LEDs and two photocells (a.k.a., LDRs) on at just the right
height, so be careful.
There’s a helpful construction video at
The LFR compares light values using the LDRs to sense
the line position, and an LM393 comparator chip controls
the motors using 8550 PNP switching transistors. The old-school cadmium-sulphide LDRs are most sensitive to
yellow/green light, yet the kit uses garden-variety red LEDs
to illuminate the line.
In spite of the fact that nothing is optimized, the line
follower works just fine; often without any adjustment at
all to potentiometers R1 and R2. Here’s my empirical
adjustment tip for the two pots. Set either one mid-range,
and switch it on. Hold it up off the ground and adjust the
other pot so both motors are half running. You’ll know the
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