Pzem always gives -1 A

[crosofg]

I have connected Pzem to ARduino Nano through Software SErial. IT alwasy gives -1A as current and all other values are also negative. What could be the reason?

[olehs]

check connection

[ovisopa]

Can anyone help me, I have the same issue, all values are -1, and I don;t understand what I did wrong , also I don;t understand what is the IP for, and what IP address is that. I have used one that is free.

Please check the attached photo to see if anything might be wrong

The settings in the code are
PZEM004T pzem(4,5); // RX,TX (D2, D1) on NodeMCU IPAddress ip(192,168,1,48);

The serial monitor reports :
-1.00V; -1.00A; -1.00W; -1.00Wh; 200 -1.00V; -1.00A; -1.00W; -1.00Wh; 200 -1.00V; -1.00A; -1.00W; -1.00Wh; 200 -1.00V; -1.00A; -1.00W; -1.00Wh; 200

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whatsapp image 2017-08-02 at 17 19 42

[pieman64]

@ovisopa in your photo you don't have any electricity going through the coil.

[ovisopa]

@pieman64 I removed the board from the place where I first installed, there I had connected both 220v wires on the empty connector, and also one of the 220v wires was passing through the coil.

But I get -1 in serial even if I dissconnect the RX / TX wires from ESP8266.. there must be something wrong with my setup, but I don't know what.

I tried to change the IP to multiple values but the same. I also tried to swap RX with TX, every reading is the same -1

[pieman64]

@ovisopa live wire through the coil presumably?

By convention the IP address of 192,168,1,1 is used but it shouldn't matter.

Do remember the ESP is a 3.3V device so technically you can't feed the Pzem tx pin directly to the rx pin on the ESP. It needs to go through a voltage divider but some people run without one. I wouldn't take the risk for the cost of a couple of resistors.

Are you mixing up GPIO references with D pin references i.e 4, 5 needs to go to D2 and D1?

And finally there is a special ESP version of SoftwareSerial called espsoftwareserial-3.2.3, are you using it?

[ovisopa]

When I first tried to flash the ESP I had some errors regarding the software serial library, but I fixed it after downloading another library, now I only get a warning when flashing the ESP.

I think the problems is regarding 5v on the PZEM004 vs 3.3v on the ESP, If I change R17 as in the photo, and power the PZEM with 3.3v from Wemos board will it work without using a voltage divider ? or a TTL level converter
https://github.com/pcgayan/PZEM004T/blob/5d39a972395d6405ac0dd86805f8d2fbb30f036b/examples/SampleWiringDiagram.jpg

, I think I purchased in the past some modules, to convert levels from 3.3 to 5v .. I need to check my inventory :D

WARNING: library PZEM004T claims to run on [avr] architecture(s) and may be incompatible with your current board which runs on [esp8266] architecture(s).

The 2 wires are connected to D1 D2 on wemos board.

UPDATE. I installed a level converter, please see the attached photo.. still not getting any value, all -1 :(

Any help is appreciated

[ovisopa]

To eliminate even one possible problem, I used an Arduino Pro Micro (Leonardo) that is runing at 5v, but I still can't get any reading, anything I can do to test if the module I purchased is working ?

Here's a video with the new setup

https://www.youtube.com/watch?v=zVeowB13q4g

Thank you.

[pieman64]

@ovisopa you seem very reluctant to show the coil. Do you have live, rather than neutral, through the coil?

[ovisopa]

I'm not trying to hide anything, the coil was hanging down, no wire through it, but it should have display the voltage, and 0w for the power.

With the ESP, I think it should display 0v even if no wire is attached to the AC connector, right ? It should be able to work when there is no power from the mains, but to be sure that is not the case TODAY I connected the AC also, but nothing through the coil

[olehs]

Yes, it should show 0V when there is no current. But No, it's IC is powered by AC voltage, so without 220V it returns an error (-1)

[ovisopa]

I have also tried to use an ESP USB programmer to connect to the PZEM module and use the chinese software provided by PEACEFAIR but there are only COM1 - COM4 options available, and my USB serial converter is shown on COM5, the other ports are already used :(

Should have worked with this adapter, is there a way to test using an USB to serial adapter like this ?

[pieman64]

@ovisopa it has just been explained to you by @olehs why you are seeing 0V. Wire up the coil but don't just randomly take "one of the 220v wires".

[olehs]

@pieman64 actually I ment coil is not needed) just 220V.
@ovisopa can you please show RX/TX connections in your Arduino setup?

[ovisopa]

@olehs , in my last test, using the 5v arduino, I had 220v connected, but I didn't know the IC is powered by AC, so when there is no AC (mains power down) I will have to make some modifications to my database, to not store -1 but 0v ... if I will make it work after all :)

Guys, any ideea what I can do to test the module if it's working are welcome. i posted the video so it will be easier for you to see the connections, if I should tell any more detail, please ask, I will post back.

I think I will purchase another one - or two modules (anyway I wanted to measure all 3 phases, not just one, but for the beggining I wanted to test one module, to see what result I get ..but not that lucky yet :( )

Thank you.