Using RobotDyn Uno + ESP board with EmonESP

I was wondering if I could use this board:

I was considering this board with the Sketch for a 2 phase setup where i need more inputs than on one EmonTx (so looking at 2 monitoring boards). The other advantage of this Arduino board is that it has an antenna socket so I can use an external antenna.

But will it work?

Interesting, not seen that board before. It looks tidy.

As long as the serial lines are connected from the Atmega328 to the esp8266 then EmonESP it should work. I’m assuming they will be.

Let us know how you get on.

So, are you saying suck it & see? I want to use 2 boards with Sketches, Wif connected back to the Emon Base.

I will order the hardware & try it then. (The boards are a reasonable price off AliExpress:,searchweb201602_2_10065_10068_10130_10547_319_317_10548_10696_10924_453_10084_454_10083_10618_10920_10921_10922_10307_537_536_10131_10132_10133_10059_10884_10887_100031_321_322_10103,searchweb201603_2,ppcSwitch_0_ppcChannel&algo_expid=4a8077d7-befc-4b75-a837-c1379cee11b7-32&algo_pvid=4a8077d7-befc-4b75-a837-c1379cee11b7 Which is basically the same board, but less memory.

regards, Doug

Sorry, I don’t understand what you mean by this. I have no firsthand experience of the board you mention. It’s impossible for me to say for sure if it should work. But I would guess that it would since EmonESP just requires serial connection.

In @Dougo’s other thread about this, I was going to look at linking two emonTx’s via the FTDI ports (using the same overall scheme as Martin Roberts’ “Full Fat” setup, but as he’s buying these boards, I shall not pursue that.

Thanks. I have ordered the EmonTx Arduino shield. & the Arduino with Wifi as before.

I thought about connecting 2 EmonTx with serial, but it is not expandable beyond 2 (to my understanding), but with the Wifi as many as is required can talk to the EmonBase, via Wifi. It is already being used, so no re-inventing the wheel, just a matter of getting around the foibles of the boards I purchased, & understanding the Wifi communication method so I set it up correctly.

My aim atm, is to monitor both phases as 2 separate but interconnected units. Eventually I will fit a battery system to my SolarEdge system (2x 5Kw inverters with Optimisers on 15Kw panels, 8Kw facing North, & 7Kw facing West. Limited to 8.4Kw export. Currently exporting 40-60Kw/day.)
My issue is the SolarEdge only updates the data on the site at 30Min intervals. Also they aggregate both phases which makes it hard to plan. I will eventually need to have my Emon energy system ‘manage’ the battery system for charging, consumption & export. I would love if Emon could be able to be aggregated into a ‘virtual’ localised power station for use in particular by our local Community owned Energy Reseller called ‘Enova’, based near me in Byron Bay, NSW Australia. (see their website for details:

regards, Doug

I hav been reading through the previous thread (that forked to this one).

I wish to ask some basic questions about the firmware:
I take it that the EmonCMS is running in the 8266? If this is the case, can I still use a local RPi to aggragate & form the data so I can use the data management to use for other purposes? (Such as PHEV, controlling Air Conditioners, Hot Water heating, Battery, etc) I o not mind having data on Emon website, but also want it stored locally. I will be using 2 boards + Tx Sketches for my 2 phases (& if I get this working, no reason it could not be used in 3x for full 3 phase system).
I would like to move to the continuous monitoring model when available.

For anyone interested, I think the Arduino board I will be using will be fine for this application. it has 8Mbytes memory associated with the 8266. for a board that cost less than $Au12, it seems good value. (Makes an economical system with Tx Sketch.)
My RPi will be linked to the Wireless router also, so I will need to work out how to get everything talking reliably to each other (I guess by allocating permanent IP address to all)

must thank everyone for the help so far.
regards, Doug
ps: just to make you all jealous, my Solar system produced 54Kw today! Lovely, sunny Australia.

5 posts were split to a new topic: PV system generation

hoe all who celebrate had a merry Christmas.

I received my board from China yesterday. It looks like it will work OK. i have built my EmonTx Arduino shield.
My issua atm is that I cannot see where to change the config in the Firmware source for the bigger Ram on the ESP8266: it has 8Mb (so double the size of the Huzzah board)
Could you please point me towards the area to edit.

fyi, I checked the documentation, & the ESP8266 is correctly connected to the serial port (set by switches: one setting to program the Arduino section, another to program the ESP, then another to link the ESP to the Arduino serial) This board also has a built in CH340 USB>Ser i/f.

Happy New Year!

well, I checked further, & the board I have is fitted with a 32Mbit chip, so equivalent to the Huzzah.

Now just learning about PlatformIO: took a bit of thought, but now working OK. Just need to workout the address of my USB port for the upload (I use PCLinuxOS, & have for many years!)

Getting there…

Hi Doug,


ls -la /dev/{tty{ACM,AMA,S,USB},serial}*

Thanks for the handy one-liner, @PB66. :wink:

I loaded the ESP8266 with EmonESP & the Arduino with Serial firmware for the sketch.

The EmonESP started with the EmonESP-xxxxx, but also the ESP s/w showed a login as well. The EmonESP will not reliably connect (Logs off after abt 20s).
I think I will try to load the Huzzah boot-loader, & see if that has an effect. It seems the ESP s/w compiled & loaded Ok, so hopefully the bootloader might help.
Anyone loaded a Huzzah bootloader?

regards, Doug (slowly getting there…)

This info is to enable the external aerial connector:
Found some useful info here:

DJManas commented on Apr 13, 2018

I was in communication with RobotDYN, I had layed the question (hope correctly).

I had seen, that there is possibility to connect external antenna for ESP8266. Do I need to unsolder any „0“ ohm resistor as in other ESP-07 boards?

And their answer is here, hope it would be helpful.

About external antenna.
Need to remove this is L2 induction.



gheesung commented on Apr 14, 2018

Hi Petr,

Thanks for the useful information. I will try out and let you know if it works.



gheesung commented on Apr 27, 2018

After I have unsoldered L2 and connected an external antenna, the signal strength seems to improve by a few dB and connection is more stable.

Thanks @DJManas for the information.


DJManas commented on Apr 27, 2018

You are welcome and thanks for testing.


jandrassy commented on Jun 14, 2018

with Mega+WiFi there is a problem with Mega. The build-in flashing is for 328p.

for reset a jumper from Uno/Mega reset pin to esp8266 io 0 on esp8266 header should work. for the esp8266 header see the bottom of the schema on Robotdyn site


Still in a bit of strife! Wiped the memory, finally, then reloaded, but the 8266 still has dual sign-ups for WIFI.

Can someone suggest a chip firmware to load over the board manufacturer original, that will work with EMonESP pls? ESPEasy might be one.

regards, Doug

I use these boards for my energy monitors for about a year, though I use the mega version that way i can use dedicated serial instead of software serials on the arduino you can probably do it with espeasy. though it would be easier with mega version of this board as they use serial port 2 connected to esp… where as uno is connected to serial port 0 so it makes it a bit harder for debugging – with mega you can debug both at the same time- but I am confuse where you a re stuck at

(Edited because I found not relevant)

I am getting the idea that the ESP8266 is not resetting before the Spiffs are loaded. It seems I need the DTR reset, but I cannot see where to actually set it. Is it in the Projectio.ini file?

Worked out the Uno+Wifi bd requires cp reset.

Still working on that issue (edited the board info to reflect ¨cp¨ instead of ´nodemcu´ Got the program to compile, but it seems to skip sub-programs, & I am not sure why:

Environment emonesp_fast [SKIP]

Environment emonesp_ota [SKIP]

Environment emonesp_spiffs [SKIP]

Environment emonesp_deploy [SKIP]

Environment emonesp01 [SKIP]

Environment emonesp_staging [SKIP]


regards, Doug

still having problems with this board (in that the original & the OpenEnergy web page comes up: really frustrating!
I have compiled a NodeMCU firmware for the board (using service.) It supplies 2 .bin images, a float & an integer. Which one should I load please?

I will beat this…

Finally some success!
To assist others: Loaded NodeMCU using compiler service using modules:
file, gpio, mqtt, net, mode, tmr, uart, wifi. (Most are standard inclusions).
Loaded NodeMCU with the command:
< --port /dev/ttyUSB0 write_flash -fm dio 0x00000 nodemcu-master-8-modules-2019-02-07-21-26-43-float.bin> (Modify the bin name & port, & poss dio)…
With new firmware, I needed to format the Spiffs with Lua, Wipe the memory (Easy now that the new version of Platformio has new version of esptool that includes wipe function) Then load the EmonESP. Because the board reset did not work, to automate Spiffs load, I reset & loaded Spiffs manually with Platformio: <pio run -t uploadfs> which loads the pre-compiled Spiffs.

The output from the Serial port (no Arduino connected) is as follows:

Terminal ready
emonTX Shield CT123 Voltage Serial Only example
71928.50 61956.96 56959.33 59417.92 596.98
36202.55 25557.10 17193.20 19402.88 423.98
18346.69 12074.80 4694.10 6105.28 301.85
10052.28 4933.42 1498.27 1990.90 223.50
5810.65 2014.57 550.46 725.12 169.83
2652.63 806.02 312.46 356.27 114.73
1125.17 349.27 245.22 266.74 74.68
417.76 211.88 228.88 224.34 45.46
28074.52 33942.36 30823.56 23389.69 371.85

I am not sure where the data came from! (no TX3 or sketch).

The other issue I have is when I start the Wifi, I am asked for a user name & password. It is the EmonESP login, but does not get to the start page. (btw, this is with the Arduino connected for wifi.)

Any ideas? I need the User name & password. (so close & yet so far…)

Little by little I am getting on top of this! I loaded the ´standard´ NonOS firmware[]=14 (after having problems because the latest version 1.7.0 does not work properly: loaded 1.6.2 which loaded with no problems. fyi, the 1.7 will not communicate correctly via the serial port. Beyond me, but the older version is OK.
My issue now is the emonESP starts with a request for a Username & password. (the shown homepage does not load). Is there a Username & Password? I compiled the normal emonESP.
In case others follow me, when the various sections are loaded, the board must be manually reset before the next section is loaded. The issue is the reset is by ck, & I could not find a board close enough to work, so left the software standard.
If I get stuck on the Pwd/User, I will edit it directly using AT commands.

regards, Doug

oh my - you have being struggling with this a long time now… soon you willrun out of flash rewrites to get that to working… I would help you more directly but I do not use emoncms so I am not that familiar. you could try my how to to get it working with espeasy and these Arduino+esp combo boards such as yours… it give you the option to send to several controllers off the shelf- including emoncms – oh well just a thought