Current Cost Optismart Optical Sensor Tear Down

A friend recently send me a Current Cost Optismart sensor to test compatibility with the emonTx / emonPi, here's what's inside the sensor: 


Brown is 0V. So LED is energised from Green via 220R.

Phototransistor has 150K pull-up to Red Vcc supply.

Black is TTL output

glyn.hudson's picture

Re: Current Cost Optismart Optical Sensor Tear Down

After a quick initial testing I can conclude that the CC optismart sensor will work with the emonTx V3 / emonPi. Using the following connections:

Red: 3.3V (terminal block 2, RJ45 pin 2)

Brown: GND (terminal block Pin 3, RJ45 pin 1)

Black: IRQ (terminal block Pin 4, RJ45 pin 6)

The LED on the rear of the sensor won't work unless the green wire is connected to a free digital I/O on the emonTx and code added to toggle this pin when a pulse is detected, on the emonTx V3 Dig19 / ADC5 could be used. 

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