Energy Monitor Shield Current Sensor

The energy monitor shield has three current sensor inputs (A0 thru A2) which have a voltage divider to provide a reference offset voltage for the analog inputs on the Netduino. The reference offset voltage with a 5V supply was 2.5V which meant on a 3.3V device the range of the sensors (1V for 30 Amps) would be compromised.

In a previous post I modified the shield by replacing a resistor but there appears to be an easier modification. While looking at the schematic and the shield I realised that cutting off the 5V pin and connecting the 3.3V pin and 5V pin together would make all the analog inputs use the 3.3V rail.

Energy Shield with modifications for 3.3V operation

Energy Shield with modifications for 3.3V operation

It would be good if the designers of the shield would consider putting a switch or jumpers on the device to allow 3V3 or 5V operation.

public class Program
public static void Main()
AnalogInput buttons = new AnalogInput(Cpu.AnalogChannel.ANALOG_0);

while (true)


One thought on “Energy Monitor Shield Current Sensor

  1. Pingback: Netduino 2 Plus AnalogInput read rates | devMobile's blog

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.