Hi All!
I would like to read pulse from this energy meter “SDM-230 pulse” PDF MANUAL
This device only have a pulse output.
I tried to detect the pulse for trigger an interrupt on Arduino without success…
Please, i need a tip!!! 
Thank you!
The “manual” that you link to provides no useful information at all. And I can find no other information about your meter.
I will guess that the terminals marked with the pulse symbol, 8-9 & 10 - 9, are the pulse connections.
Have you connected a voltmeter to those terminals, and can you see a voltage pulse at all? I think it is not very likely that the meter will give out a voltage, but you must check this first.
If you cannot see a voltage, I will guess (again a guess) that inside the meter, these terminals connect to an opto-transistor. Try connecting a red LED, a resistor of about 3.9 kΩ and a 9 V battery all in series across 8 - 9 or 10 - 9, with the battery positive to 8 or 10. If you see a dim flash, then my guess was correct. If not, try with the connections to terminals reversed.
This may help you.. It’s the same manufacturer but a different meter.
Post when you have some more information.
Hi Robert,
thank you for your kind reply!
I had already done all that tests you suggest on pins 8-9 (pulse1)… with no success.
Reading your reply, i understand i was an the correct path…
Reading the manual, i understand that pulse1 (8-9) is configurable.
Unfortunately my device have the LDC broken, so i can read anything on the display!
I decide to switch on pulse2 (10-9) and… everything is working good!!!
So… yes, the pins are passive and terminals are connect to an opto-transistor.
- led, resistor 3.9 kΩ and a 9 V battery all in series pin 9 +, pin 10 -: works
- led, resistor 3.9 kΩ and a 9 V battery all in series pin 9 -, pin 10 +: works better
- pull down to ground A0 arduino pin: 9 = gnd, 10 = A0 (HIGH): works and trigger the interrupt!
- may be the pulse1 (8-9) should be enabled into device configuration.
Thank you very much again!