Hi All,
Im looking to get started on my first project using these resources (theres alot here!)
Im currently located in Australia and looking to monitor up to 15 individual circuit breakers on a single phase feed
From what I understand so far is that its possible to stack multiple emonTx boards (http://openenergymonitor.org/emon/node/1170)
Is there a better way to do this?
Is it going to scale to that number of ct's? (ie 5 x emonTx)
From my understanding ill need to buy the following:
- Build and setup an emonTX (times the number of ct's i want)
- number of ct sensors required
- EmonBase to collect the data
- *optional* emonGLCD (if i want the lcd visulisation of data)
Many thanks in advance!!!
Re: Large Number of CT's on emonTx
Hello!
Here are my (theoretical) thoughts:
I don't think that it would be much better but maybe you can get another ATMEGA that has enough analog inputs (16) for your project, build a new board and connect all the sensors to this board. Of cause you would have to write your own software to support it.
The easier way is to add more emonTx devices. As they are connected via I2C bus the maximum would be 112 devices (7 bit adresses) or 1136 (10bit adresses) on the bus. I think before you reach this limitation you would be limited by the RF much earlier.
I think it's also important to do calibration to ensure that the same current produces the same measurement on every channel, so maybe it would be a good idea to use a single (bigger) voltage regulator for all 5 ATmega's, so the reference voltage of all ADCs is the same.
Re: Large Number of CT's on emonTx
You can have a look at this thread: http://openenergymonitor.org/emon/node/1170
Re: Large Number of CT's on emonTx
As jb79 said, there shouldn't be any problem stacking 5 boards and they are fairly cheap and very quick to assemble, especially as you don't need to install all the parts on the all the boards.
If you want full voltage and current measurement you'll need the a/c input but if you put a stackable header pin on the relevant pin on P3 you should be able to put the jack and input circuitry on one board and it will just feed through to the others. You could probably do this with the 3.3V too if you did want to use a single regulator.