Ferrais Energy Counter with TCRT5000

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Tinteex
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Ferrais Energy Counter with TCRT5000

#1 Post by Tinteex » 25 Aug 2022, 19:19

Hello gentlemen,

i saw many of you use Pulsecounters for IR smartmeters.
Sadly i am still suck with an old ferrais meter (75 Rotations equals to 1kWh)

I followed another Project, which made use of a schmitt trigger to reduce unclean triggers.
Sadly it seems to be abandoned and i was unable to make it work.

Could someone maybe share some insights to me, how to make my Wemos D1 Mini count current Watts & kWh?
This is the old project i followed, it allowed me to connect to the AP and select my wifi, then sadly it kept refusing any http requests and was inaccesible:
https://github.com/mrebbert/FerrarisPow ... /main.cpp
What would i need to put into the bottom fields?
I Apologize, all this smarthome stuff is new for me. :oops:
Screenshot_21.png
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Cheers

TD-er
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Re: Ferrais Energy Counter with TCRT5000

#2 Post by TD-er » 25 Aug 2022, 19:37

Well first of all, congratulations with your Ferraris meter.
It is still by far the best one if you ever plan to have solar panels.
Also it is far more likely to not malfunction compared to "smart" meters which often have to be replaced when the metering company is for whatever reason not able to read out your meter.

The only disadvantage here is that it only does 75 rev per kWh, which means you will only get an update every so many minutes when you're not consuming a lot of energy.
For example, even when using 500 Watt continuously, you will only see 37 or 38 pulses per hour.

This makes it a bit hard to get a good reading of the change in reflection when the colored spot of the wheel passes.
Some meters also have a magnet on the wheel so you could use a hall effect sensor, which is easier to mount.

Anyway you need an LED illuminating the wheel and a photo transistor to pick up the reflected signal.
This is a bit tricky.
If you get a strong enough signal, you can use the pulse counter. However since the interval of pulses can be so long,
I'm not sure whether your domotica system needs a pulse interval, or the power in Watt or Wh consumed.
Also if outputting consumed power in Wh, do you need to output the total amount, or just the Wh consumed since the last update?

Also does it need to get an update ever N seconds, or as soon as you have a new measurement?

All have their pros and cons.
- Update every N seconds may also send out a "0" inbetween, which may give a rather irregular pattern if not averaged.
- Update every update (thus every rotation) may result in a very long time since the last update and if the last output value was in Watt (not Wh) then the logging system may over-estimate the consumed power

I think the best way is to output the total Wh consumed since the last update.
This way you don't need to keep track of the total on the ESP and it makes processing way more easier.
But then your domotica system needs to be able to process only "delta" values.

So what kind of information can your domotica system handle?

Tinteex
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Posts: 3
Joined: 25 Aug 2022, 19:10

Re: Ferrais Energy Counter with TCRT5000

#3 Post by Tinteex » 25 Aug 2022, 20:00

Im even more confused than before. :lol:

Basicly i want the Wemos to give me the same data as a smart plug with energy measurement

Current Watt usage - like what is used right now. (to be able to see my usage and solar production to compare it) , and todays kWh usage (which updates every lets say 30 seconds)
Homeassistant will then simply add it up 0.02kWh .... 0.03kWh and then homeassistant on its own will produce the 7 days / 1 month / 1 year graphs.

so basicly my homeassistant instance needs the power in Watt and energy in kWh

i deeply apologize for being so cryptic, like im said im very new on this topic lol.

TD-er
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Re: Ferrais Energy Counter with TCRT5000

#4 Post by TD-er » 25 Aug 2022, 23:09

The output values are:
Count: Number of counted pulses since last transmission (Delta)
Total: Total number of counted pulses (since power on or cold restart)
Time: Time between current and most recent pulse in milliseconds

N.B. the values are in this order.

See:
https://espeasy.readthedocs.io/en/lates ... escription

The "total" and "count" are very easy to convert to Wh (or kWh)
75 turns = 1 kWh
Thus 1 turn is 1/75 kWh.
For the formula field:

Code: Select all

%value%/75
You need to use the Time value to compute the energy in Watt.
So this means you may get "0" if the interval is too short for your power consumption.

If you're using 1000 Watt continuously, you've used 1 kWh after 1 hour.
This means the expected time between pulses is then 3600/75 = 48 sec per pulse. (=48000 msec)

So to compute the output in Watt, use this as formula in the 3rd task value:

Code: Select all

%value%/3600*75
You can already simplify this a bit, since /3600*75 is constant:

Code: Select all

%value%/48

Tinteex
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Re: Ferrais Energy Counter with TCRT5000

#5 Post by Tinteex » 26 Aug 2022, 15:37

Thank you very much.

since 1 rotation every 48 sec equals 1000 kWh, does that mean if i change my update intervall to 10x (480s) that i should not get a "0" watt error, since the 480 seconds should be fine for an usage of atleast 100 watt?

meaning, granted the sensor works perfectly, i should not get zero values , if my home uses more than 100 watts?

TD-er
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Re: Ferrais Energy Counter with TCRT5000

#6 Post by TD-er » 26 Aug 2022, 16:12

Tinteex wrote: 26 Aug 2022, 15:37 [...]
meaning, granted the sensor works perfectly, i should not get zero values , if my home uses more than 100 watts?
Yep.

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