Last time, we built a simple robot car by adding a PICAXE 08M2 brain and IR sensor
to an inexpensive RC car. “RoboCar” used all three GPIO (general-purpose
input/output) pins C.1, C. 2, and C. 4, plus the serial out pin C.0 to control H-bridges
for drive and steering, which left us with just input-only pin C. 3. To that, we
connected an IR proximity sensor to avoid obstacles and receive IR remote control
codes. Our little 08M2 was maxed out in terms of I/O pins. To get more I/O pins, we
could either learn to use more advanced I2C commands (beyond the scope of this
article) or switch to a bigger PICAXE chip. You may remember that both 14M2 and
20M2 chips can plug in this breadboard in place of the 08M2. However, this
month's robot will keep the 08M2 and incorporate various ways to get the most out
of each I/O pin.
BASIC Bots &
By Eric Ostendorff
PICAXE Processors
36 SERVO 01.2016
Part 5: Building the Cruiser Robot
