Both motor speed and direction are easily controlled using the picAxe 14m. The speed and direction motor drives most small DC electric motors up to 1A stall current. It uses the Toshiba TA 8080K to drive the motor. This is a chance to exercise the capabilities of the 8080. Yes, the 8080 which gives some of us flashbacks to the early microprocessor days!

Steering is controlled by using a servo. In the buggy bot, this servo turns steerable front wheels. While you can also use the servo to steer the drive wheels as in the tricycle robot base project.

What is a picAxe?

A picAxe is a pic microcontroller (In this case a PIC16F684.) with a built-in BASIC Language Interpreter. Yes, it eats up a bit of memory and can do only a limited number of things. But you cannot beat a pixAxe for experimenting and playing around. If you use them correctly, they can serve well. But you may need to dedicate the chip. For example, dogBot used a picAxe 14m just like this project. It could drive Servos, OR Drive Electronic Motor Controllers. Trying to get it to do both is pushing the capabilities.

When you need to use more of the chips capabilities, you get a bigger chip, or you program the PIC16F684 in a compiled language instead of as a picAxe.

picAxe 8m`s are other examples, while the chip itself can decode IR signals, the limitations on number of pins restrict it from many applications. An m8 can control a motor, but little else. The 14m in this project uses all the available outputs and could still use more. Achieve complexity by using more than one chip. (Or go straight to assembly language or C compiler which gives you much more memory, but makes programming difficult.)