Hi
I hope someone can help me, this is a part from a post from the old forum, but i still need to get it working.
The problem is that i have to interface my Arduino UNO with a Heat energy meter, the meter has a interface where i won't to connect my arduino to,
but i can not get any response from the meter, so i think the problem is to "drive" the OPTO isolator.
So now i tried to connect my arduino to the Heat meter with a resistor but no result.
From Arduino Heat meter
Pin0 <= 10kOhm resistor <= Data Out "J1=7" from the interface.
Pin1 => 10kOhm resistor => Data Req "J1=6" to the interface.
GND GND
I got the schematic over the heat meter where i do the interfacing, but they told me with a TTL i have to put in a 1 k Ohm resistor and a 4,7 k Ohm pull up resistor.
So i did following.
But this did not work, i talk again with the company and they think that a pull op resistor on the TX from the arduino will help, but i don't not know what size and how to connect it.
So i hope someone have a idea or another way to get i working.
Jesper
Datasheet over the opto isolator http://pdfcast.org/pdf/1716003-sharp-pc357