Grove - Electricity Sensor

The Electricity sensor module is a member of Grove. It is based on the TA12-200 current transformer which can transform the large AC into small amplitude. You can use it to test large alternating current up to 5A.



Application Ideas


Key Specification

Items Min
PCB Size 2.0cm*4.0cm
Interface 2.0mm pitch pin header
IO Structure SIG,NC,NC,GND

Electronic Characteristics

Items Min Norm Max Unit
Transformation ratio - 2000:1 - -
Input Current 0 - 5 A
Output Current 0 - 2.5 mA
Sampling Resistance - 800 - Ω
Sampling Voltage 0 - 2 V
Working Frequency 20 - 20K HZ
Nonlinear scale - - 0.2% -
Phase Shift - - 5' -
Operating Temperature -55 - 85
Dielectric strength - 6 - KVAC/1min


With Arduino

The following sketch demonstrates a simple application of measuring the amplitude of the alternating voltage.The SIG pin will output a alternating voltage based on the alternating current being measured. You can measure the value using ADC.

//	Function: Measure the amplitude current of the alternating current and 
//			  the effective current of the sinusoidal alternating current.
//	Hardware: Grove - Electricity Sensor		
//	Date: 	 Jan 19,2013
//	by
#define ELECTRICITY_SENSOR A0 // Analog input pin that sensor is attached to

float amplitude_current;               //amplitude current
float effective_value;       //effective current 

void setup() 
void loop() 
	int sensor_max;
	sensor_max = getMaxValue();
	Serial.print("sensor_max = ");
	//the VCC on the Grove interface of the sensor is 5v
						//Only for sinusoidal alternating current
	Serial.println("The amplitude of the current is(in mA)");
	Serial.println(amplitude_current,1);//Only one number after the decimal point
	Serial.println("The effective value of the current is(in mA)");
void pins_init()
/*Function: Sample for 1000ms and get the maximum value from the SIG pin*/
int getMaxValue()
	int sensorValue;             //value read from the sensor
	int sensorMax = 0;
	uint32_t start_time = millis();
	while((millis()-start_time) < 1000)//sample for 1000ms
		sensorValue = analogRead(ELECTRICITY_SENSOR);
		if (sensorValue > sensorMax) 
			/*record the maximum sensor value*/
			sensorMax = sensorValue;
	return sensorMax;

Note: The minimum effective current that can be sensed by the code can be calculated using the equation below. minimum_current=1/1024*5/800*2000000/1.414=8.6(mA).

With Raspberry Pi

1.You should have got a raspberry pi and a grovepi or grovepi+.
2.You should have completed configuring the development enviroment, otherwise follow here.

4.Navigate to the demos' directory:

   cd yourpath/GrovePi/Software/Python/
   nano   # "Ctrl+x" to exit #
import time
import grovepi

# Connect the Grove Electricity Sensor to analog port A0
sensor = 0


# Vcc of the grove interface is normally 5v
grove_vcc = 5

while True:
        # Get sensor value
        sensor_value = grovepi.analogRead(sensor)

        # Calculate amplitude current (mA)
        amplitude_current = (float)(sensor_value / 1024 * grove_vcc / 800 * 2000000)

        # Calculate effective value (mA)
        effective_value = amplitude_current / 1.414

        # minimum_current = 1 / 1024 * grove_vcc / 800 * 2000000 / 1.414 = 8.6(mA)
        # Only for sinusoidal alternating current

        print "sensor_value", sensor_value
        print "The amplitude of the current is", amplitude_current, "mA"
        print "The effective value of the current is", effective_value, "mA"

    except IOError:
        print "Error"

5.Run the demo.

   sudo python



If you have questions or other better design ideas, you can go to our forum or wish to discuss.

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