Adding a 7 segment display to Arduino mk2 pv diverter small problem

My first post I have been in the back ground for some time and would like to thank everybody that has posted information on this forum.

I built last year a solar pv diverter based on: Robins mk2 Solar diverter for sale, on the services offered page.

It has been working with no problems with just an led on the Arduino pin 13.

I have since upgraded to a 7 segment 4 digit display running mk2-bothdisplays-1.ino

I am using 2 x sct-013-30 cts with no additional burden resistor, 1 for the incoming supply and 1 for the display

I added the extra circuit required to pin 1+2 on the ic and 2 extra diodes to copy the original circuit to pin AN.

I had to increase power cal to 0.1520 diverted when running a load test to get the led display to read correctly.

Now everything is working fine the water is heating up as before but when the immersion stat opens so there is no load the led display counts 1 watt every 24 to 25 seconds this will continue all the time there is no load. The diverter will shut down correctly and restart the following day.

  Thank you 

Les

Robert Wall's picture

Re: Adding a 7 segment display to Arduino mk2 pv diverter small problem

"when the immersion stat opens so there is no load the led display counts 1 watt every 24 to 25 seconds this will continue all the time there is no load"

Is that your problem? It is most likely due to noise picked up from somewhere. I know Robin has improved his board design over time to reduce this, (and I also know where he is today, so he probably won't see this for 24 hours or so) but I suspect the easy answer will be to add a line of code to suppress the display when the count is small.

rob1953's picture

Re: Adding a 7 segment display to Arduino mk2 pv diverter small problem

Thank you for your reply. Robert

Yes the led display counting on is the small issue.

The pcb is my own design. The immersion is up to temperature at the moment so I unclipped  the display CT and it is still counting on at the same rate.

Les

 

 

Robert Wall's picture

Re: Adding a 7 segment display to Arduino mk2 pv diverter small problem

If you look at Robin's latest (Rev 6a) sketch, you'll see:

#define ANTI_CREEP_LIMIT 5 // in Joules per mains cycle (has no effect when set to 0)

You need to adjust that (or add it to your code / move to this version!).

rob1953's picture

Re: Adding a 7 segment display to Arduino mk2 pv diverter small problem

 Robert

 

I have used the sketch that I have loaded it has the anti-creep code.

I increased the value up to 60 which then gave 1 watt on the display every 8 minutes which is ok with me.

That would be 75 watts for a 10 hour run time.

As a point of interest 10 gave 3m 36s

                                30 gave 4m 30s

Thank you for your help.

Les

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