emonTx : multiple pulse counters

Due to various tariffs and usage billing, I have 3 meters in my switchboard box. I'm petty sure that all have a pulse/optical output (too dark to check now).

How difficult would it be to build an emonTx that will support more than 1 pulse input?

Obviously I could put 3 emonTxs in the meter box but I'd prefer not to :-)

glyn.hudson's picture

Re: emonTx : multiple pulse counters

Pules counting utilizes the ATmega328's hardware interrupts. Unfortunately the ATmega328 only has two hardware interrupts. On the emonTx one is used for the RFM12B and the other for the pulse counting port. So no, you would not be able to add another pulse counting input.

It is possible to use a dedicated ATmega328 with low level port reading to take up to 12 pulse inputs. We have documentation for this in the building blocks section. This works well, but has not been developed further than than breadboard testing. 


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