Page 214 - 15 Dangerously Mad Projects for the Evil Genius

190 15 Dangerously Mad Projects for the Evil Genius

Figure 15-8 Testing a motor controller module

The “BANG!” condition is both interesting and
TABLE 15-1 Results of Pin A and B
important. What it signifies is that if both A and B
A B Result are connected to V at the same time, then both
MOSFET transistors will be on at the same time,
GND or no GND or no Motor stopped
connection connection meaning there is effectively a short circuit between
8V and ground. This will result in very large
+V GND or no Motor turns
connection clockwise currents flowing through the transistors, which will
probably result in smoke and destruction.
GND or no +V Motor turns
connection counterclockwise This is something we must keep at the fore of
+V +V BANG! our thinking when it comes time to write the
software for the Arduino.