Efergy e2 power meter

[korttoma]

Hi @gtortone ,
I finally found some time to hock up the RFM12B. Seems to be almost working. I just get the value "inf" for current. Do I have some datatype problem or maybe it should be calculated differently my Efergy engage hub?
I'm using a Arduino Pro Mini 3.3V

Attached the serial print.0_1484211281663_efergyLog.txt

I should see values around 100W most of the time and some smaller down to 30W.

Edit: It seems like it might be payload[6] that is equal to 255 at 100W and 254 at under 40W that is causing problems with the calculation.

Edit2: Took 3 samples at around 30W, 60W and 100W. 0_1484220204136_efergyLog2.txt I need to find something so that I could test higher values to so I could figure out the formula to use.

[gtortone]

Hi @korttoma,
happy to read that you are getting "reasonable" values from RFM12B !!

but I agree that in your case the decoding protocol needs some refinements...
just a question: your line voltage is 110 or 240 ?

take into account that from Efergy current sensor you get the value of "current" and
not "power" than for 30W expected value from data is (V/30) [Ampere]...

[gtortone]

Hi @korttoma,
take a look to this decoding based on your collected data for 30W, 60W and 100W;

everything seems to be ok !!

Regards,
Gennaro

p.s. I checked in your profile that you live in Finland and power voltage is 220/240 V :-)

• bytes #1: 0x09 fixed value
• bytes #2: 0X50 fixed value
• bytes #3: 0x2E fixed value
• bytes #4: 0x40 fixed value
• bytes #5: current MSB
• bytes #6: current LSB
• bytes #7: exponent
• bytes #8: CRC
• current detected = ((MSB << 8) + LSB / 65535) / pow(2, (255-exponent))

30 W = 0.13 A (@220V)

9 - 0x09
80 - 0x50
46 - 0x2E
64 - 0x40

71 - 0x47
172 - 0xAC
254 - 0xFE
184 - 0xB8

0x47AC = 18348

current = 18348 / 65535 / pow(2, 1) = 0.139 A

60 W = 0.26 A (@220V)

9 - 0x09
80 - 0x50
46 - 0x2E
64 - 0x40

69 - 0x45
29 - 0x1D
255 - 0xFF
40 - 0x28

0x451D = 17693

current = 17693 / 65535 / pow(2, 0) = 0.269 A

100 W = 0.45 A (@220V)

9 - 0x09
80 - 0x50
46 - 0x2E
64 - 0x40

112 - 0x70
163 - 0xA3
255 - 0xFF
217 - 0xD9

0x70A3 = 28835 (10)

current = 28835 / 65535 / pow(2, 0) = 0.439 A

[korttoma]

Thanks @gtortone your formula seems to work. I just need to find a way to test higher values.

I almost had the same formula but I did not have the "65535". Could you explain where you got this value from?

-- S --
9
80
46
64
76
204
254
221
-- E --
abc_value = 19660current = 0.15A - power = 34.50 W
23701 TSF:MSG:SEND,9-9-0-0,s=9,c=1,t=17,pt=2,l=2,sg=0,ft=0,st=OK:34
OK = 4 - short pk = 0 - long pk = 0 - crc bad = 0
-- S --
9
80
46
64
71
173
255
186
-- E --
abc_value = 18349current = 0.28A - power = 64.40 W
29693 TSF:MSG:SEND,9-9-0-0,s=9,c=1,t=17,pt=2,l=2,sg=0,ft=0,st=OK:64
OK = 5 - short pk = 0 - long pk = 0 - crc bad = 0
-- S --
9
80
46
64
115
51
255
108
-- E --
abc_value = 29491current = 0.45A - power = 103.50 W
35688 TSF:MSG:SEND,9-9-0-0,s=9,c=1,t=17,pt=2,l=2,sg=0,ft=0,st=OK:103
OK = 6 - short pk = 0 - long pk = 0 - crc bad = 0

[gtortone]

Hi @korttoma,

the value 65535 or 32768 often is used as multiplier from sensor that send metric;
usually when you have to send a "small" float value (temperature, current) you can send it as integer
multiplied by a big constant instead of sending it with a float value converted in binary...

I just refined my formula with this that is more close to formula I found for my Efergy using a small
constant:

current = 18348 / 32768 / pow(2, 255-254 + 1) = 0.139 A
current = 17693 / 32768 / pow(2, 255-255 + 1) = 0.269 A
current = 28835 / 32768 / pow(2, 255-255 + 1) = 0.439 A

[korttoma]

Hi @gtortone I'm working on finalizing this node and I'm having some trouble with stability. The node stays alive from a few minutes to 30min and then stops communicating.

What kind of decoupling capacitors are you using in your setup?
I now have 2 pc 0.1uF, 2 pc 47uF and one 0.33uF.

I use a HLK-PM03, a Pro Mini 3.3, and the NRF24L01+

Debugging output don't give me much to go in since it just stops responding.

[gtortone]

@korttoma

Hi,
at the moment I'm defining some things in order to use RFM69 modules...
in the past, on my NRF24L01+ I was using 10 uF capacitor but I had same problems of "stop responding"...

[korttoma]

@gtortone My node has now been running for more then 40min since I added the 0.1uF and 0.33uF tantalum caps. I'm hoping this will be the solution for me since I have no tools to debug any disturbance like this.

EDIT: It failed again :(

[korttoma]

Tried exchanging the NRF24L01+ with an RFM69 but it does not seem to work at all with this setup. Might be because the RFM69 is using the same frequency as the RFM12B or maybe I can not have the 2 in the same node because they are related.

[korttoma]

@gtortone did you have any chance to look at the "stop responding" issue of this device?

I tried to add some more debug prints to your code today but if I add them to the wrong places the efergy receive function stops working and receives only 0 value. I guess it messes with the timing.

[gtortone]

@korttoma Hi, I just returned to play with Efergy and Arduino. I realized that debug messages on UART reset the micro. Now I'm skipping (with a #define DEBUG and #ifdef) all debug messages and it seems to work fine. But take into account that now I'm not using any radio module... just to test the firmware.

[korttoma]

:D What a coincidence. I returned to this project today also. Now trying to set this up as an Ethernet GW with local sensor without NRF radio. I still have to share the SPI bus with the Ethernet module though. I'll let you know how it goes.

I think I did try removing the serial prints earlier but I'm not sure..

[korttoma]

The ethernet GW approach performs even worse than your original solution. I get one or 2 measurements and then nothing. Still responds to ping but no communication with the controller.
I don't know how to debug this since it just stops working. Is there by any chance anything in the code that consumes memory?

[ailiev]

Hi All,

First of all, great work man!

I was wondering do you know if we need to have established link between the wireless sensor and the receiver?

I only have the wireless sensor so I was wondering if I can use this without the receiver?

Any thoughts?

[korttoma]

@ailiev it "works" without the receiver but for me the node fails after about 1h so I gave up. I could try again now with the new MySensors 2.2.0 lib to see if it makes any difference (when I find some time).

[shifaz]

Hi,

I have been trying to receive the efergy signal using RFM69 and so far it's a dead end. I'm unable to receive any data on the RFM69 module.

Since you guys talked about RFM69 module here, I thought you might have some insight to share.

[gohan]

@shifaz I think you need the RFM12B to receive the data you want

[Jens Lauridsen]

@gtortone

Any chance that I can see how you wired up the NRF24L01+? I bought the parts back in January 2017 and just found it in a drawer this evening. I assembled everything but the NRF24L01+ and I am a bit stuck right now.

BTW: Great build - I really hope that I will get mine up and running :)

/Jens

[banda banda]

Since you guys talked about RFM69 module here, I thought you might have some insight to share. (spam links removed by moderator)

[MaurettoFarmer]

@korttoma
I resume an old topic: i'm trying to receive data from Energy2 whith arduino connected to an RXB6. I can't receive any data, and i don't know how to substitute the code block related to RF12 with a correct one for my receiver. Can someone help me? Thanks in advance, Mauro