EmonTX to Rpi - Direct Serial Connection

[crazynight]

So have the signal and gnd connected as per the photos have tried

com_port= /dev/ttyUSB0

in the file emonhub.conf

and com_port = /dev/ttyRS485-0

neither seem to work nothing is appearing in the inputs screen any way of fault finding.

The TX unit has no lights on it well just one red light on start up for a 5 seconds.

[borpin (Brian Orpin)]

Linked post for reference Pre Order Question - #6 by crazynight

[Robert.Wall]

Did you go back to the original link, where there’s a link to the software changes required:

https://wiki.openenergymonitor.org/index.php/EmonTx_V3.4#Direct_connection_emonTx_V3_.3E_Raspberry_Pi_GPIO

That page predates the latest versions of both emonTx software and the RPi’s - one immediate thing to check is baud rates. The emonTx is almost certainly using 115200, not 9600.

[borpin (Brian Orpin)]

Is this an EmonSD image you are running?

[crazynight]

yes it is a EmonSD

I have edited the file as per the link https://github.com/openenergymonitor/emonhub/tree/emon-pi/conf/interfacer_examples/directserial-serialtx3e

Add the following to emonhub.conf in the [interfacers] section:

[interfacers]
### This interfacer manages the EmonTx3 ESP format serial
[[SerialTx3e]]
     Type = EmonHubTx3eInterfacer
      [[[init_settings]]]
           # Un-comment line below if using RS485 adapter
           #com_port = /dev/ttyRS485-0
           # default com port if using USB to UART adapter
           com_port= /dev/ttyUSB0
           com_baud = 115200
      [[[runtimesettings]]]
           pubchannels = ToEmonCMS,

[crazynight]

So I had been entering the commands via ssh and not using the Emonhub.After entering the parameters above I am now seeing

or

depending which line I uncomment

[borpin (Brian Orpin)]

I think it might be /dev/serial0

@crazynight

# default com port if using USB to UART adapter

Note the comment refers to a USB port adapter for that not the RPi GPIO pins.

[crazynight]

@borpin

/dev/serial0

spot on with /dev/serial0 I now have some data coming through

although not consistent and lots of errors

amended the conf file further to rem out the [[RFM2Pi]] section and it seems to have solved it.

my interfaces section now looks like this

[interfacers]

### This interfacer manages the EmonTx3 ESP format serial
[[SerialTx3e]]
     Type = EmonHubTx3eInterfacer
      [[[init_settings]]]
           # Un-comment line below if using RS485 adapter
           com_port = /dev/serial0
         #com_port = /dev/ttyRS485-0
         # default com port if using USB to UART adapter
         #com_port= /dev/ttyUSB0
           com_baud = 115200
      [[[runtimesettings]]]
           pubchannels = ToEmonCMS,


### This interfacer manages the RFM12Pi/RFM69Pi/emonPi module
#[[RFM2Pi]]
#    Type = EmonHubJeeInterfacer
#    [[[init_settings]]]
#        com_port = /dev/ttyAMA0
#        com_baud = 38400                        # 9600 for old RFM12Pi
#    [[[runtimesettings]]]
#        pubchannels = ToEmonCMS,
#        subchannels = ToRFM12,
        

       group = 210
        frequency = 433
        baseid = 5                              # emonPi / emonBase nodeID
        calibration = 230V                      # (UK/EU: 230V, US: 110V)
        quiet = true                            # Disable quite mode (default enabled) to enable RF packet debugging, show packets which fail crc
        # interval =  300                         # Interval to transmit time to emonGLCD (seconds)
        

[[MQTT]]

    Type = EmonHubMqttInterfacer
    [[[init_settings]]]
        mqtt_host = 127.0.0.1
        mqtt_port = 1883
        mqtt_user = emonpi
        mqtt_passwd = emonpimqtt2016

    [[[runtimesettings]]]
        pubchannels = ToRFM12,
        subchannels = ToEmonCMS,

        # emonhub/rx/10/values format
        # Use with emoncms Nodes module
        node_format_enable = 1
        node_format_basetopic = emonhub/

        # emon/emontx/power1 format - use with Emoncms MQTT input
        # http://github.com/emoncms/emoncms/blob/master/docs/RaspberryPi/MQTT.md
        nodevar_format_enable = 1
        nodevar_format_basetopic = emon/

[[emoncmsorg]]
    Type = EmonHubEmoncmsHTTPInterfacer
    [[[init_settings]]]
    [[[runtimesettings]]]
        pubchannels = ToRFM12,
        subchannels = ToEmonCMS,
        url = https://emoncms.org
        apikey = xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
        senddata = 1                    # Enable sending data to Emoncms.org
        sendstatus = 1                  # Enable sending WAN IP to Emoncms.org MyIP > https://emoncms.org/myip/list
        sendinterval= 30                # Bulk send interval to Emoncms.org in seconds

[borpin (Brian Orpin)]

Yes /dev/ttyAMA0 and /dev/serial0 are probably the same physical port.

[crazynight]

Thanks again for your help I have something working, just need to extend two of the CT clamps and then will be in business.

[Bill.Thomson]

@crazynight

amended the conf file further to rem out the [[RFM2Pi]] section and it seems to have solved it.

That makes sense. With it enabled, you had a com port conflict. i.e. two devices were configured to use the same serial port at the same time.

[borpin (Brian Orpin)]

I’m trying to do this with an RPi Zero on a new shop emonTX (not modified in any way).

Can anyone tell me the difference between the EmonHubSerialInterfacer and the EmonHubTx3eInterfacer please?

[Robert.Wall]

Glyn did, way back:

emonHub ttyUSB0 USB serial adapter

I hope you don’t mind, I moved this question to a new topic. The short answer is yes; you will just need to create a new entry in emonhub.conf in the [interfacers] section, you can edit this via the local Emoncms web interface. There are two options depending on serial format: 1. EmonHubTx3eInterfacer This interface handles name value key pairs e.g. name:value,name:value. This is the default serial output for latest emonTx V3 and emonTH FW. Config example: [interfacers] ### This interface…

[borpin (Brian Orpin)]

Thanks.

I got this running quite easily in the end

Next question, to power the emonTX via the RPi (so I only use 1 power supply), do I need to do anything other than remove the DC supply from the emonTX and connect the 5V from the RPi to the emonTX?

I do also have a 9V AC/AC PS connected.

[Robert.Wall]

You can leave the emonTx powered by the a.c. adapter if you wish - it might be cleaner than the PI’s 5 V.

Otherwise, feed it the Pi’s 5V and pull the jumper off so that you don’t backfeed the “a.c.” supply regulator.

[borpin (Brian Orpin)]

@Robert.Wall

Otherwise, feed it the Pi’s 5V and pull the jumper off so that you don’t backfeed the “a.c.” supply regulator.

That was what I wondered if I needed to do.

I’ll just leave it ‘as is’ and supply the emonTX via DC and AC and the Pi by a separate DC.

Cheers

[Bill.Thomson]

@borpin

I’ll just leave it ‘as is’ and supply the emonTX via DC and AC and the Pi by a separate DC.

That’ll ensure each component gets enough current, but it’s also a good idea to bond
them all together via their respective “ground” connections to ensure a common earth.

[borpin (Brian Orpin)]

@Bill.Thomson

to bond them all together via their respective “ground” connections to ensure a common earth.

That sounded a bit like blah blah blah

You’ll need to explain that a bit more…

[Bill.Thomson]

The idea is to tie the components together via a single connection from each component, then
earthing that connection. The “connection” is usually a chassis or “frame,” but lacking that, the negative power terminal on each component can be used. Doing that keeps all of the voltages referenced to a common point.

It’s a lesson I learned when I did GPS testing for the USAF.

“Component” means the Pi, the emonTx, and anything else that is powered.

[borpin (Brian Orpin)]

Ok, but how could I do that? All I have exposed is the ground pin.