I have the emonTX setup and code uploaded to the UNO running the shield. I found the “calibration = 220V” part of the code and changed it to be 110V. I currently do NOT have a AC/AC 9v plugged in and the two CT clips that I ordered from the store are connected to each leg in my breaker box. this emonTX is replacing a Aeon HEM gen2 that used to read 500w-2000w all day long. the emonTX is reading 40w-50w. what am i missing?
I think to be able to calculate the power, you need both voltage and current reading.
So both the AC/AC 9v plugged and CT clips are needed (mandatory), to calculate the power.
With the two CT clips attached, you only get current - but not yet the voltage.
understood. its just that my current USED to be in the 500w as a low and spikes in the 2k-3k range and big devices kicked on. its now with the emonTX attached in the 40w-50w range… seems really too low
Hi Dave,
You say ‘current’ but you use ‘w’ (Watt; power) as the measurement unit…? Just want to make sure we are in the same boat.
Yeah… sorry… its early here. ill wait for my 9V AC/AC to get here
1 Like
So let’s assume that 40w-50w is actually the actual current reading (40Amps - 50 Amps), then with simple P=VxI formula, the estimated power reading you will get will be 4400w-5500w, assumed 110V and power factor = 1.
It will be too big. I think better wait the AC/AC being plugged in.
Wouldn’t it be better to read the source code for the sketch and find out what’s actually happening? There’s a big risk of posting misleading or basically wrong information here.
Agreed Robert, actually I don’t know what that 40w-50w really is, that’s just an assumption.
EDIT:
Just saw @glyn.hudson posting this minutes ago:
Maybe the problem that the OP face now related to this?
Checking my firmware version now
is what I am running now. how do I tell the version?
maybe I need to use the version without the Voltage until I get my 9v plug?
Hi Dave,
I’m looking at the code now. By the way, Glyn said in the post that that bug is specifically for emonTx V3. You are using emonTx shield.
1 Like
I just read the code you’ve used, IMHO the bug that Glyn has posted is not applicable to emonTx shield.
Hope the openenergymonitor team can confirm this.
I think in the firmware you’ve used, the real voltage is needed (sensed from the AC/AC wall adaptor), otherwise the power calculation will yield wrong result.
And if I’m not mistaken, there is a calibration factor that you need to change to calibrate the voltage. It will render useless if you don’t have the AC/AC adaptor plugged in.
Can you post the actual output from your serial monitor? Just curious how it looks like without the AC/AC adaptor.
Yes I will but I will have to do that when I get home tonight. my wife would not let me run a serial cable down the hall to the power box 
Hold… I can get some info from the web server
haha my wife won’t either 
. Sure no problem.
2017-02-24 20:03:59,838 INFO RFM2Pi Publishing: emon/emontxshield/power1 48
2017-02-24 20:03:59,844 INFO RFM2Pi Publishing: emon/emontxshield/power2 44
2017-02-24 20:03:59,849 INFO RFM2Pi Publishing: emon/emontxshield/power3 0
2017-02-24 20:03:59,855 INFO RFM2Pi Publishing: emon/emontxshield/power4 0
2017-02-24 20:03:59,861 INFO RFM2Pi Publishing: emon/emontxshield/vrms 9.72
2017-02-24 20:03:59,866 INFO RFM2Pi Publishing: emon/emontxshield/rssi -55
2017-02-24 20:03:59,872 INFO RFM2Pi Publishing: emonhub/rx/6/values 48,44,0,0,9.72
2017-02-24 20:03:59,877 INFO RFM2Pi Publishing: emonhub/rx/6/rssi -55
2017-02-24 20:03:59,883 DEBUG RFM2Pi 15836 adding frame to buffer => [1487966639.817512, 6, 48, 44, 0, 0, 9.72, -55]
2017-02-24 20:03:59,886 DEBUG RFM2Pi 15836 Sent to channel(end)' : ToEmonCMS
2017-02-24 20:04:00,826 DEBUG RFM2Pi Discarding RX frame 'unreliable content'? 11 35 1 (-96)
2017-02-24 20:04:02,256 DEBUG RFM2Pi 15837 NEW FRAME : OK 6 50 0 47 0 0 0 0 0 169 3 (-52)
2017-02-24 20:04:02,263 DEBUG RFM2Pi 15837 Timestamp : 1487966642.26
2017-02-24 20:04:02,265 DEBUG RFM2Pi 15837 From Node : 6
2017-02-24 20:04:02,268 DEBUG RFM2Pi 15837 Values : [50, 47, 0, 0, 9.370000000000001]
2017-02-24 20:04:02,270 DEBUG RFM2Pi 15837 RSSI : -52
2017-02-24 20:04:02,272 DEBUG RFM2Pi 15837 Sent to channel(start)' : ToEmonCMS
2017-02-24 20:04:02,276 INFO RFM2Pi Publishing: emon/emontxshield/power1 50
2017-02-24 20:04:02,281 INFO RFM2Pi Publishing: emon/emontxshield/power2 47
2017-02-24 20:04:02,286 INFO RFM2Pi Publishing: emon/emontxshield/power3 0
2017-02-24 20:04:02,292 INFO RFM2Pi Publishing: emon/emontxshield/power4 0
2017-02-24 20:04:02,298 INFO RFM2Pi Publishing: emon/emontxshield/vrms 9.37
2017-02-24 20:04:02,303 INFO RFM2Pi Publishing: emon/emontxshield/rssi -52
2017-02-24 20:04:02,308 INFO RFM2Pi Publishing: emonhub/rx/6/values 50,47,0,0,9.37
2017-02-24 20:04:02,314 INFO RFM2Pi Publishing: emonhub/rx/6/rssi -52
2017-02-24 20:04:02,395 DEBUG RFM2Pi 15837 adding frame to buffer => [1487966642.25532, 6, 50, 47, 0, 0, 9.370000000000001, -52]
2017-02-24 20:04:02,397 DEBUG RFM2Pi 15837 Sent to channel(end)' : ToEmonCMS
2017-02-24 20:04:04,095 DEBUG RFM2Pi Discarding RX frame 'unreliable content'? 6 38 127 244 10 56 185 232 142 111 251 116 85 233 123 187 249 66 255 37 101 (-93)
2017-02-24 20:04:04,622 DEBUG RFM2Pi 15838 NEW FRAME : OK 6 42 0 53 0 0 0 0 0 167 3 (-54)
2017-02-24 20:04:04,636 DEBUG RFM2Pi 15838 Timestamp : 1487966644.62
2017-02-24 20:04:04,639 DEBUG RFM2Pi 15838 From Node : 6
2017-02-24 20:04:04,665 DEBUG RFM2Pi 15838 Values : [42, 53, 0, 0, 9.35]
2017-02-24 20:04:04,667 DEBUG RFM2Pi 15838 RSSI : -54
2017-02-24 20:04:04,670 DEBUG RFM2Pi 15838 Sent to channel(start)' : ToEmonCMS
2017-02-24 20:04:04,707 INFO RFM2Pi Publishing: emon/emontxshield/power1 42
2017-02-24 20:04:04,751 INFO RFM2Pi Publishing: emon/emontxshield/power2 53
2017-02-24 20:04:04,798 INFO RFM2Pi Publishing: emon/emontxshield/power3 0
2017-02-24 20:04:04,814 INFO RFM2Pi Publishing: emon/emontxshield/power4 0
2017-02-24 20:04:04,825 INFO RFM2Pi Publishing: emon/emontxshield/vrms 9.35
2017-02-24 20:04:04,834 INFO RFM2Pi Publishing: emon/emontxshield/rssi -54
2017-02-24 20:04:04,844 INFO RFM2Pi Publishing: emonhub/rx/6/values 42,53,0,0,9.35
2017-02-24 20:04:04,859 INFO RFM2Pi Publishing: emonhub/rx/6/rssi -54
2017-02-24 20:04:04,897 DEBUG RFM2Pi 15838 adding frame to buffer => [1487966644.621311, 6, 42, 53, 0, 0, 9.35, -54]
2017-02-24 20:04:04,900 DEBUG RFM2Pi 15838 Sent to channel(end)' : ToEmonCMS
Edit - formatted text, BT, Moderator
Got to keep the WAF high
WAF rated 1-10
Wife Acceptance Factor
A 133" wide TV with a bunch of cables hanging out has a low WAF
I also cannot post anymore for another 19 hours. due to my account being new
If that’s the version you’re using, it will be using noise pickup only for the voltage. There’s nothing in there to detect the presence or otherwise of the a.c. voltage monitor, so it will assume the voltage it picks up is the true system voltage. So your “power” is the product of current and noise.
That’s a “feature” of GitHub. I’ve never seen any understandable form of version control.
Sorry but what is ‘WAF’?