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Link to the shop

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  • 3 AC current input port
  • 1 AC Voltage port
  • 2 Relays 250V/10A

AC and Temperature Reading

The RPICT3V1_RLY2 is the same unit as the RPICT3V1 with 2 relays added.

Refer to the RPICT3V1 for full documentation covering the AC reading side.

Relay Control


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Each relay port is a 3 way screw terminal block with the following connection:

  • NO - Normally Open (Left)
  • CO - Common (Middle)
  • NC - Normally Closed (Right)

Technical specs

Relays are HLS8L-DC5V.

The datasheet is available here.


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The 2 relays are connected to GPIO5 and GPIO6 on the raspberrypi.

These can be easily controlled with the RPi.GPIO module from python.

We made a small script to get you started with this. This can be downloaded as follow:

wget lechacal.com/RPICT/tools/lcl-gpio-toggle.py.zip
unzip lcl-gpio-toggle.py.zip

This utility simply toggles the relay state. For example to change the state on the first relay (i.e. gpio5) one will execute

python lcl-gpio-toggle.py 5

The code of the utility is given below.

import RPi.GPIO as GPIO
import sys
pin = int(sys.argv[1])
GPIO.setup(pin, GPIO.OUT)
state = GPIO.input(pin)
if state:
    GPIO.output(pin, GPIO.LOW)
    print "GPIO%d Low" % pin
    GPIO.output(pin, GPIO.HIGH)
    print "GPIO%d High" % pin

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