Chapter 7. Voltage Sensors

In Chapter 5, you learned that the NXT converts the voltage on a sensor input into a digital value. Until now, the only voltage being converted was the 5V supply inside the NXT or some part of it divided through an external resistor. It probably doesn't come as a big surprise that you can connect an external voltage to the input and have the NXT convert that instead.

Warning

Never connect these voltage sensors to anything but low-voltage, battery-operated equipment. Connecting them to household electricity could be lethal both to you and the NXT.

Design of a −5V to +5V Sensor

Figure 7-1 shows a circuit diagram of the NXT input with a simple voltage sensor. The only component needed is a 10kΩ resistor. The external voltage ...

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