# emonTx **URL:** https://community.openenergymonitor.org/c/hardware/emontx/14.md [Latest](https://community.openenergymonitor.org/latest.md) · [Categories](https://community.openenergymonitor.org/categories.md) · [Tags](https://community.openenergymonitor.org/tags.md) --- ## [About the emonTx category](https://community.openenergymonitor.org/t/about-the-emontx-category/58)
**Author:** [@glyn.hudson](https://community.openenergymonitor.org/u/glyn.hudson)\ **Replies:** 0
Wireless Energy Monitoring Node emonTx V3 Resources User Guide emonTx V3 Hardware & Offical Firmware Misc emonTx firmware examples emonTx V3 Hardware Docs emonTx Forum Category --- ## [Is there a max number of TX6s](https://community.openenergymonitor.org/t/is-there-a-max-number-of-tx6s/29972)
**Author:** [@Rachel](https://community.openenergymonitor.org/u/Rachel)\ **Replies:** 5\ **Last updated:** [14 May 2026 08:13 UTC](https://community.openenergymonitor.org/t/is-there-a-max-number-of-tx6s/29972 "2026-05-14T08:13:52Z")
@glyn.hudson is there a limit on the number of emonTx6 that can communicate with the Pi3? I seem to remember there might have been with the Tx4, but can.t see any reference to that here. I’m considering using these f… --- ## [2x optical pulse sensors with emonTx4](https://community.openenergymonitor.org/t/2x-optical-pulse-sensors-with-emontx4/29965)
**Author:** [@coltcc](https://community.openenergymonitor.org/u/coltcc)\ **Replies:** 5\ **Last updated:** [11 May 2026 12:42 UTC](https://community.openenergymonitor.org/t/2x-optical-pulse-sensors-with-emontx4/29965 "2026-05-11T12:42:33Z")
Morning everyone. I’m trying to connect two optical pulse counting sensors to an emonTx4. The emonTx is connected to emonBase over USB. The first pulse counter is obvious: straight into the RJ45. For the second pulse cou… --- ## [Connect emonTX4 to emonPi2](https://community.openenergymonitor.org/t/connect-emontx4-to-emonpi2/29929)
**Author:** [@grod55](https://community.openenergymonitor.org/u/grod55)\ **Replies:** 8\ **Last updated:** [6 May 2026 17:30 UTC](https://community.openenergymonitor.org/t/connect-emontx4-to-emonpi2/29929 "2026-05-06T17:30:44Z")
Hi Angus, I was looking to use some TXv4 that I have to connect to my existing emonPi2s to use as expansion ports using USB instead of 433Mhz (the environment is too noisy for reliable RF signals). Connecting the TXv4 … --- ## [Im assuming emonTXShield project is archived and there are no kits](https://community.openenergymonitor.org/t/im-assuming-emontxshield-project-is-archived-and-there-are-no-kits/29778)
**Author:** [@jem.green](https://community.openenergymonitor.org/u/jem.green)\ **Replies:** 3\ **Last updated:** [24 February 2026 17:04 UTC](https://community.openenergymonitor.org/t/im-assuming-emontxshield-project-is-archived-and-there-are-no-kits/29778 "2026-02-24T17:04:40Z")
Possibly i am wrong which would be good, if not. Has anyone got them febricated in the UK. Has anyone got any surplus board. Note: I can build from perfboard so not an issue and would redesign to work with ESP8266. --- ## [emonTX4 firmware release](https://community.openenergymonitor.org/t/emontx4-firmware-release/29698)
**Author:** [@borpin](https://community.openenergymonitor.org/u/borpin)\ **Replies:** 0\ **Last updated:** [6 February 2026 19:15 UTC](https://community.openenergymonitor.org/t/emontx4-firmware-release/29698 "2026-02-06T19:15:09Z")
I was wanting to update my TX4 and had forgotten about this. I dutifully went to the TX4 and was looking for the latest release which was 64 commits behind the main. I then came across this. Can something be done to t… --- ## [EmonTx4's unstable behavior](https://community.openenergymonitor.org/t/emontx4s-unstable-behavior/28935)
**Author:** [@FredM67](https://community.openenergymonitor.org/u/FredM67)\ **Replies:** 107\ **Last updated:** [13 November 2025 05:22 UTC](https://community.openenergymonitor.org/t/emontx4s-unstable-behavior/28935 "2025-11-13T05:22:04Z")
Hi all, This thread is a “copy” of an issue I wrote a couple of days ago. Here, it’ll be more visible, maybe other users experienced the same problem. Playing around with an ESP32-expansion board and ESPHome, I could n… --- ## [Possible to move CT from EmonPi to EmonTX3 with historical data?](https://community.openenergymonitor.org/t/possible-to-move-ct-from-emonpi-to-emontx3-with-historical-data/29327)
**Author:** [@fergalom](https://community.openenergymonitor.org/u/fergalom)\ **Replies:** 2\ **Last updated:** [3 November 2025 21:22 UTC](https://community.openenergymonitor.org/t/possible-to-move-ct-from-emonpi-to-emontx3-with-historical-data/29327 "2025-11-03T21:22:18Z")
Per title, I need to move my emonpi location and therefore move the mains CT from the emonpi to a emontx3. Is it possible to keep / move the historical data for the CT so its still available? Have tried some forum sear… --- ## [Would like to upgrade old firmware on my emonTx V3 device](https://community.openenergymonitor.org/t/would-like-to-upgrade-old-firmware-on-my-emontx-v3-device/29268)
**Author:** [@jvda](https://community.openenergymonitor.org/u/jvda)\ **Replies:** 21\ **Last updated:** [2 November 2025 17:03 UTC](https://community.openenergymonitor.org/t/would-like-to-upgrade-old-firmware-on-my-emontx-v3-device/29268 "2025-11-02T17:03:23Z")
Many years ago I have bought an emonTX V3 device that has worked fine all the time. Now I want to update the firmware to: \* emontx3/firmware/emonTx34/emonTx\_3Phase\_PLL at master · openenergymonitor/emontx3 · GitHub As… --- ## [EmonTx5 Configuration](https://community.openenergymonitor.org/t/emontx5-configuration/29096)
**Author:** [@bri61](https://community.openenergymonitor.org/u/bri61)\ **Replies:** 3\ **Last updated:** [15 September 2025 15:35 UTC](https://community.openenergymonitor.org/t/emontx5-configuration/29096 "2025-09-15T15:35:23Z")
Hello, I have recently purchased an EmonTx5 (6CT) and EmonVs to monitor a circuit in another part of the house. I am currenly running an EmonPi2 to monitor solar panels. When I go into Emoncms, I see a new node 27 with … --- ## [Using the Web Tool for EmonTx4/5 configuration](https://community.openenergymonitor.org/t/using-the-web-tool-for-emontx4-5-configuration/28871)
**Author:** [@rupert](https://community.openenergymonitor.org/u/rupert)\ **Replies:** 3\ **Last updated:** [17 July 2025 17:01 UTC](https://community.openenergymonitor.org/t/using-the-web-tool-for-emontx4-5-configuration/28871 "2025-07-17T17:01:25Z")
Following on from the topic EmonTx5 Serial Web Connection Note: The hardware of the emonTx4 is basically the same as the emonTx5. Although I don’t have an emonTx5 to test this, the following should be applicable (I ho… --- ## [EmonTx5 Serial Web Connection](https://community.openenergymonitor.org/t/emontx5-serial-web-connection/28832)
**Author:** [@macrowe777](https://community.openenergymonitor.org/u/macrowe777)\ **Replies:** 41\ **Last updated:** [14 July 2025 17:34 UTC](https://community.openenergymonitor.org/t/emontx5-serial-web-connection/28832 "2025-07-14T17:34:20Z")
Trying to connect an EmonTx5 via serial to the web serial tool without success: I have 3 machines, unfortunately all Manjaro linux so no variation there, 2 laptops and one desktop. I am able to connect the EmonTX via US… --- ## [EmonTx5 Inputs Mirrored](https://community.openenergymonitor.org/t/emontx5-inputs-mirrored/28843)
**Author:** [@macrowe777](https://community.openenergymonitor.org/u/macrowe777)\ **Replies:** 5\ **Last updated:** [14 July 2025 11:35 UTC](https://community.openenergymonitor.org/t/emontx5-inputs-mirrored/28843 "2025-07-14T11:35:07Z")
Hey, Pretty stumped by this one. On only one of my 12 channel EmonTx5’s I have 3 inputs that are always the same no matter the number of CTs attached to them. The rest of the inputs, I believe act correctly. For clari… --- ## [EmonTx5 Input Mapping](https://community.openenergymonitor.org/t/emontx5-input-mapping/28837)
**Author:** [@macrowe777](https://community.openenergymonitor.org/u/macrowe777)\ **Replies:** 3\ **Last updated:** [12 July 2025 16:39 UTC](https://community.openenergymonitor.org/t/emontx5-input-mapping/28837 "2025-07-12T16:39:36Z")
What should be the input mapping of the EmonTx5 modules? I was assuming 1 to 1. Here I have a single CT attached to input labelled 10 on the EmonTx5 unit. No other CTs attached. However its showing up in Emonhub seemin… --- ## [Node ID for EmonTx5 with Expansion Board](https://community.openenergymonitor.org/t/node-id-for-emontx5-with-expansion-board/28836)
**Author:** [@macrowe777](https://community.openenergymonitor.org/u/macrowe777)\ **Replies:** 3\ **Last updated:** [12 July 2025 15:39 UTC](https://community.openenergymonitor.org/t/node-id-for-emontx5-with-expansion-board/28836 "2025-07-12T15:39:01Z")
This is more an FYI for future users (or myself) as I cant find it documented. It appears EmonTx devices with expansion from 6 to 12 channels are programmed to have the first 6 channels as Node ID = N and the second 6 ch… --- ## [Emontx4 saved config lost](https://community.openenergymonitor.org/t/emontx4-saved-config-lost/28771)
**Author:** [@FredM67](https://community.openenergymonitor.org/u/FredM67)\ **Replies:** 6\ **Last updated:** [25 June 2025 13:12 UTC](https://community.openenergymonitor.org/t/emontx4-saved-config-lost/28771 "2025-06-25T13:12:51Z")
Hi all, Yesterday, I saw a very strange behavior when I was playing around with a self-made ESP32-Expansion board. This board does not have anything wired to Emontxv4, except GND, +3.3, TX, RX. My emontxv4 was configu… --- ## [Is it OK to lengthen the line from an emonVS to an emonTX?](https://community.openenergymonitor.org/t/is-it-ok-to-lengthen-the-line-from-an-emonvs-to-an-emontx/28755)
**Author:** [@Guff666](https://community.openenergymonitor.org/u/Guff666)\ **Replies:** 8\ **Last updated:** [23 June 2025 18:00 UTC](https://community.openenergymonitor.org/t/is-it-ok-to-lengthen-the-line-from-an-emonvs-to-an-emontx/28755 "2025-06-23T18:00:28Z")
I’m looking at the practicalities of mounting my emonTX and emonVS. The latter is BIG and - realistically - it’s going to be very difficult to mount it anywhere close to either my consumer unit or the meter - the space … --- ## [Unable to move emonTx5 to node 28](https://community.openenergymonitor.org/t/unable-to-move-emontx5-to-node-28/28728)
**Author:** [@Guff666](https://community.openenergymonitor.org/u/Guff666)\ **Replies:** 5\ **Last updated:** [19 June 2025 09:40 UTC](https://community.openenergymonitor.org/t/unable-to-move-emontx5-to-node-28/28728 "2025-06-19T09:40:17Z")
I have newly acquired emonTx5. By default, this uses node 27, but I already have an additional emonTH on that address. According to the documentation, the address can be changed to 28 using the switch on the board. Comp… --- ## [emonTX needs repair \[edit - it didn't!\]](https://community.openenergymonitor.org/t/emontx-needs-repair-edit-it-didnt/28720)
**Author:** [@lamixer](https://community.openenergymonitor.org/u/lamixer)\ **Replies:** 8\ **Last updated:** [10 June 2025 20:19 UTC](https://community.openenergymonitor.org/t/emontx-needs-repair-edit-it-didnt/28720 "2025-06-10T20:19:30Z")
Hello. I’m not sure how to contact support for store orders, I seem to be directed here, though I also sent a message from the store order area. My emon tx unit from order #31530 seems to have died last night. It is not… --- ## [Newbie - Hardware compability for emonTX v3](https://community.openenergymonitor.org/t/newbie-hardware-compability-for-emontx-v3/28364)
**Author:** [@b72](https://community.openenergymonitor.org/u/b72)\ **Replies:** 1\ **Last updated:** [31 March 2025 12:57 UTC](https://community.openenergymonitor.org/t/newbie-hardware-compability-for-emontx-v3/28364 "2025-03-31T12:57:25Z")
Hi, I have a emonTX v3 connected to the solar panels, and I would like to build a Raspberry Pi based monitoring hub. My understanding is that I will need the following hardware: Raspberry Pi (with SD card) 433MHZ rece… --- ## [EmonLibCM - Version 2 (Support)](https://community.openenergymonitor.org/t/emonlibcm-version-2-support/9242)
**Author:** [@Robert.Wall](https://community.openenergymonitor.org/u/Robert.Wall)\ **Replies:** 93\ **Last updated:** [24 March 2025 17:10 UTC](https://community.openenergymonitor.org/t/emonlibcm-version-2-support/9242 "2025-03-24T17:10:32Z")
I have created this topic for any comments or support queries about EmonLibCM - Version 2.2.1 (Released 30/10/2021) and subsequent revisions. --- ## [Emontx and emonesp](https://community.openenergymonitor.org/t/emontx-and-emonesp/28073)
**Author:** [@sajjad\_ali](https://community.openenergymonitor.org/u/sajjad_ali)\ **Replies:** 1\ **Last updated:** [22 February 2025 08:17 UTC](https://community.openenergymonitor.org/t/emontx-and-emonesp/28073 "2025-02-22T08:17:13Z")
I flashed emontx v3 direct serial ino in Arduino Uno …on Arduino serial monitor data shows correctly but Serial data won’t show on emonesp data tab except emontx serial --- ## [Tx4 CT6 not sending Energy data](https://community.openenergymonitor.org/t/tx4-ct6-not-sending-energy-data/27943)
**Author:** [@mnbf9rca](https://community.openenergymonitor.org/u/mnbf9rca)\ **Replies:** 9\ **Last updated:** [9 February 2025 12:37 UTC](https://community.openenergymonitor.org/t/tx4-ct6-not-sending-energy-data/27943 "2025-02-09T12:37:25Z")
How do i get my Tx4 with a new 6CT expansion to create inputs and feeds for E6-12? Here’s the options when i select “initialize” Also, the Tx4 doesnt seem to actually be sending energy data since i switched to the 12… --- ## [CT expansion for emonTx3?](https://community.openenergymonitor.org/t/ct-expansion-for-emontx3/27911)
**Author:** [@jcnoernberg](https://community.openenergymonitor.org/u/jcnoernberg)\ **Replies:** 1\ **Last updated:** [5 February 2025 11:40 UTC](https://community.openenergymonitor.org/t/ct-expansion-for-emontx3/27911 "2025-02-05T11:40:46Z")
Any options to add more CT? --- ## [Tx4 6CT expansion board](https://community.openenergymonitor.org/t/tx4-6ct-expansion-board/27890)
**Author:** [@mnbf9rca](https://community.openenergymonitor.org/u/mnbf9rca)\ **Replies:** 2\ **Last updated:** [2 February 2025 18:05 UTC](https://community.openenergymonitor.org/t/tx4-6ct-expansion-board/27890 "2025-02-02T18:05:49Z")
Where can i get a Tx4 6CT expansion board? I note from the post What's happened to emonTx V4? - #67 by TrystanLea that the Tx4 is discontinued, but the hardware still has significant life left for those of us willing to … --- ## [Mysterious null results on a single monitored branch circuit](https://community.openenergymonitor.org/t/mysterious-null-results-on-a-single-monitored-branch-circuit/27238)
**Author:** [@davidski](https://community.openenergymonitor.org/u/davidski)\ **Replies:** 25\ **Last updated:** [8 December 2024 14:17 UTC](https://community.openenergymonitor.org/t/mysterious-null-results-on-a-single-monitored-branch-circuit/27238 "2024-12-08T14:17:11Z")
I have an odd failure to get any readings from a particular branch circuit. I’m using an EmonTX5 w/12 ports on US power (split phase, 120V, 60Hz). Using a 20 Amp CT from the OEM shop on the target line gives me a static… --- ## [Factor 10 on power on emonhub with emonTx5?](https://community.openenergymonitor.org/t/factor-10-on-power-on-emonhub-with-emontx5/27296)
**Author:** [@antoinev](https://community.openenergymonitor.org/u/antoinev)\ **Replies:** 10\ **Last updated:** [5 December 2024 13:48 UTC](https://community.openenergymonitor.org/t/factor-10-on-power-on-emonhub-with-emontx5/27296 "2024-12-05T13:48:56Z")
Good evening, I’m new user on EmonTx5 12 CTS (with EU emon VS, 20A CT) and during test, I have a factor 10 on the power of electric heater. Anyway the emonTx code doesn’t seem to include this factor 10. We are wondering… --- ## [Understanding the avrdude (EmonTX5) firmware config options](https://community.openenergymonitor.org/t/understanding-the-avrdude-emontx5-firmware-config-options/27167)
**Author:** [@davidski](https://community.openenergymonitor.org/u/davidski)\ **Replies:** 3\ **Last updated:** [17 November 2024 01:06 UTC](https://community.openenergymonitor.org/t/understanding-the-avrdude-emontx5-firmware-config-options/27167 "2024-11-17T01:06:49Z")
Related to my other post on compiling the avdude firmware, there are a couple config options which I’m looking to get more info on: -) The USA option is hardcoded (for EmonTX5 at least) to false. Since I’m in the US wi… --- ## [Difficulties compiling EmonTX5 (avrdude) firmware](https://community.openenergymonitor.org/t/difficulties-compiling-emontx5-avrdude-firmware/27166)
**Author:** [@davidski](https://community.openenergymonitor.org/u/davidski)\ **Replies:** 5\ **Last updated:** [16 November 2024 20:14 UTC](https://community.openenergymonitor.org/t/difficulties-compiling-emontx5-avrdude-firmware/27166 "2024-11-16T20:14:28Z")
I’m trying to compile the avrdude firmware for my EmonTX5 following the OEM guide and using PlatformIO. I’m encountering an error related to a missing dependency: \/avrdb\_firmware/emon\_DB\_12CT/emon\_DB\_12CT.ino:… --- ## [Suggested mounting hardware for EmonVS](https://community.openenergymonitor.org/t/suggested-mounting-hardware-for-emonvs/27141)
**Author:** [@davidski](https://community.openenergymonitor.org/u/davidski)\ **Replies:** 0\ **Last updated:** [13 November 2024 15:35 UTC](https://community.openenergymonitor.org/t/suggested-mounting-hardware-for-emonvs/27141 "2024-11-13T15:35:15Z")
I want to wall mount my EmonVS. The ears on the EmonVS case have very small openings, much smaller than the screw sized holes on EmonTX devices. I’ve only been able to get thin nails through the holes, which is not a ver… [Next page](https://community.openenergymonitor.org/c/hardware/emontx/14.md?page=1)