S26 Smart Plug support

[CoarsePiglet]

Hello

Smart On Off just recently released the S26 Smart Plug. It's a new version of the S20 Smart Plug. I see support is not yet added for this. So here's me requesting it.

Thank you in advance guys! Only now gonna start using your software but I have a feeling it will be great! ;)

[thomasleitner]

Thx. However I don’t think that it’s a software problem. As I’ve explained, when reconnecting to an external 3,3v supply, it works great. Only when reassembled and connected to 230v AC power, it does not power up. Hmm ...

[rzr]

maybe be not but it could help to narrow the problem, If you want to discuss more join: irc://irc.freenode.net/#iot

[dugite-code]

@thomasleitner could it be the button it getting pushed by the casing? The LED might not be on because it's gone into flash mode.

I know the button extender on mine will sometimes get caught in the case because it's not a flat surface, kind of a design flaw in the S26 IMHO

[thomasleitner]

@dugite-code yes I was already thinking about that, but the button feels as if it would click when the case is assembled. I’ll double check, though ... thanks ...

[pwaldon]

Hey,

is it safe to reflash S26 with 2.6.0 firmware, or it doesn't matter? (Some time ago I had 1.8.1 but the new one is 2.6.0, dunno why).

[rzr]

I am wondering is it a good idea to backup the stock fw to eventually reflash later ? is it scripted or documented anywhere ?

[dugite-code]

@rzr if you're using esptool like I do it's in the wiki

[dugite-code]

@pwaldon I have 2.6.0 on mine and it works fine

[neirbomn]

I have tried flashing these after following this thread and Jon Oxer SuperHouse Episode 31. I think I have a power related issue as flashing results in the "A fatal error occurred: Failed to connect to Espressif device: Timed out waiting for packet header" error. To rule out issues with the MacBook I used an ESP-01 and a cheap USB adapter for flashing these. All good. I conclude that it's a power issue therefore as I know the USB Serial adapter is good but it produces ~3.3V (possibly slightly less as my cheap multimeter reads it as 3.25V). Can I use a LiPo battery to "up the voltage" a bit as I'm pretty sure there's not enough juice for the flashing procedure? I'm thinking I could do VCC and GND from battery and just use the serial connection for Tx and Rx. Would this work? I don't have a bench supply but I may be able to get access to one. The other idea I had would be to extract the ESP breakout board and then flash this before resoldering it. In this case, how would I tie GPIO 0 to GND? Is there a contact for this on the ESP board? (Edit: OK found details for this here. I am going to try the LiPo route first.)

[rzr]

I managed to flash mine , but I have to say that getting to flashing mode is not straightforward.

Also I'd be curious to compare what is differing in original images backuped from different devices...

[neirbomn]

I managed to flash mine

Do you mind if I ask you for details of what your process was to successfully flash them? I've soldered onto pads for all without success and also using the Jx points under the board. I'm using the same Freetronics USB Serial adapter as Jon Oxer and the latest esptool. Scoured the troubleshooting section looking for a solution but without success yet. I would really like them to work. I've temporarily junked one of them by pulling off the solder pad inadvertently so that's a job for another day. Starting to wish I'd bought the S20s instead.

[rzr]

I used exptool from git at 460800 baudrate and address 0x000000

In my notes:

    $esptool \
        --port ${port} \
        write_flash \
        $address \
        $@

    Wrote 454864 bytes (313424 compressed) at 0x00000000 in 27.6 seconds (effective 131.8 kbit/s)...

And for the USB/UART adapter I think i git it along nodemcu like ESP8266, I can get the reference if needed

[dugite-code]

Hey, I got that error when I hadn't pushed the button firmly enough, it was a bit sticky on mine. Is the led flashing?

On February 23, 2019 8:32:06 AM UTC, neirbomn notifications@github.com wrote:

I have tried flashing these after following this thread and Jon Oxer SuperHouse Episode 31. I think I have a power related issue as flashing results in the "A fatal error occurred: Failed to connect to Espressif device: Timed out waiting for packet header" error. To rule out issues with the MacBook I used an ESP-01 and a cheap USB adapter for flashing these. All good. I conclude that it's a power issue therefore as I know the USB Serial adapter is good but it produces ~3.3V (possibly slightly less as my cheap multimeter reads it as 3.25V). Can I use a LiPo battery to "up the voltage" a bit as I'm pretty sure there's not enough juice for the flashing procedure? I'm thinking I could do VCC and GND from battery and just use the serial connection for Tx and Rx. Would this work? I don't have a bench supply but I may be able to get access to one. The other idea I had would be to extract the ESP breakout board and then flash this before resoldering it. In this case, how would I tie GPIO 0 to GND? Is there a contact for this on the ESP board?

-- You are receiving this because you were mentioned. Reply to this email directly or view it on GitHub: https://github.com/arendst/Sonoff-Tasmota/issues/2808#issuecomment-466629208

[neirbomn]

@dugite-code Thanks for that but no flashing on LEDs on S26.

@rzr I've tried pulling the breakout ESP board off the main board and the LiPo approaches with the same error as a result. LED flashes when I don't ground GPIO 0 so I'm assuming the S26s I have work. I bought them from iTead directly. I really can't see what I'm doing wrong here.

[rzr]

have you managed to backup the stock fw ? I can try to diff your image with mine to see if there is any hw version or others hints ?

[neirbomn]

have you managed to backup the stock fw ? I can try to diff your image with mine to see if there is any hw version or others hints ?

Thank you for the offer and thanks for helping me out, problem is I get the same error when attempting to backup stock fw. It's definitely not getting into the bootloader properly or it's crashing early once there and I can only conclude that it's a power issue. I used a different adapter to flash an ESP-01 and this worked.

I have a few things left to try and then I'm out of ideas. Really wish I'd gone for the S20s now!

1. Try and flash with the ESP-01 adapter. Same as this one. I know this works with ESP8266, just not with S26. (This doesn't work)
2. Try with a bench supply... (if I can get hold of one)

[neirbomn]

And for the USB/UART adapter I think i git it along nodemcu like ESP8266, I can get the reference if needed

@rzr Could you find a reference for this too? My USB to Serial device uses the ATmega16u2 MCU. I have flashed the ESP-01 and decided to use the esptool and settings with an Adafruit Huzzah to load the sonoff.bin file. It didn't work at the low baudrate. I omitted the baudrate and all was ok. The only device I haven't checked is the USB to Serial device I have. If yours works then I may as well try this too. I have another device but even though it has a switch for 3.3V the Vout remains at 5V. I may use the Vout from the ATmega and the Tx and Rx from the other device...

[rzr]

I have it here "sds011_usb2ttl_004" is printed on pcb and it looks like:

As this bug is closed, maybe you can continue this thread to esptool project ?

[MatzeMuc86]

Dear community, I started using Tasmota a few weeks ago successfully for my NodeMCU + DHT 22 and love it. THank you so far for the great software and development! Now I tried to flash my Sonoff S26. Flashing was successful (at least what I assume) with version 6.4.1.19 and Visual Studio Code. I can access the Tasmota web interface via browser, changed the module to Sonoff S2X (8) and can toggle the switch. I even can hear the relay working but nothing happens. I tried a second Sonoff S26 which I used before with original firmware and it behaves the same way. Same if I change to generic device and manually assign GPO12 to relay1 or relay1i. So I am out of ideas why it seems to work properly but it is not working as expected. Any hints? Thank you and best MatzeMuc86

[AndyP2]

I might have found a simpler method to avoid the "fatal error occurred: Timed out waiting for packet header" error. I was using tasmotizer - power on with the button pressed, release button, start the flashing process. It backed up the original firmware then timed out and gave me the error. However, if I held the button down for the whole of the upload process it flashed successfully; hopefully this will help others who have the same problem.

[phrfpeixoto]

@PJFonseca @freynder @vogler I'm sorry to revive this old issue, but I'm having issues getting this flashed. I'm seeing continuity between 3.3v and GND pads on the board, but the device still works. Is this expected?

Also, I'm using this to try and flash, would it work? https://pt.aliexpress.com/item/32953781344.html?src=google&src=google&albch=shopping&acnt=494-037-6276&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=UneMJZVf&&albagn=888888&albcp=1626568036&albag=65942329430&trgt=539263010115&crea=pt32953781344&netw=u&device=c&albpg=539263010115&albpd=pt32953781344&gclid=EAIaIQobChMI3-3Trs-76AIVDoWRCh3K5Q0eEAQYASABEgJlCPD_BwE&gclsrc=aw.ds

[AndyP2]

It depends what you are measuring continuity with. There is a circuit between them, through the esp8266 itself. It should not be a dead short though. I could not see how you set the txd output level to 3.3v on that board, sending 5v to the esp8266 on any pin is not advised. Measure it! You might get away just using a potential divider. I don't know if it will recognise the levels correctly on the rxd pin either, but that should be safe to try.

[phrfpeixoto]

Nevermind, I just noticed that I've ripped the TX pad from the board. =( I guess I'm doomed with this one?

[AndyP2]

It's all down to your physical soldering skills now. Is the pad still connected? The trace from that pad must have gone somewhere, if you follow it maybe you can connect a wire to it somewhere else. I guess it depends on whether the device has any value you might lose by trying.

[phrfpeixoto]

Yeah, I have shaky hands, so I'm guessing not possible. Also, these are too small components, and I don't have a magnifier or microscope. =(

If someone knows another spot for this TX pin, please let me know

[jpslootmans]

Does anyone know how to use the button on a S26 plug as a separate switch in domoticz? I would like to use the input to decide if the plug state was changed by pushing the button (admin) or a script.

[growse]

In case anyone's interested, they seem to have changed the design on the S26 to make the pads much more accessible.

[jpslootmans]

Hello Andrew,

thank you for the information and the nice picture. Maybe you can help me with something that bothers me for some time. I have a lot of tasmotized smart plugs in operation and some scripts to switch them on or off for different reasons. I would like to distinguish between an automated switching by a script and a manual switching by pushing the button on the plug. This to prevent that my script switches the plug back on, when I have manually switched it off. Do you know of a way to do that? I just need to get the right information if the button has been pushed, I think.

thanks in advance, JP

Op di 21 dec. 2021 om 12:12 schreef Andrew Rowson @.***

:

In case anyone's interested, they seem to have changed the design on the S26 to make the pads much more accessible.

[image: signal-2021-12-21-102241_001] https://user-images.githubusercontent.com/378067/146920701-17b1440a-9212-41f7-97fd-7189a36664c2.jpeg

— Reply to this email directly, view it on GitHub https://github.com/arendst/Tasmota/issues/2808#issuecomment-998691421, or unsubscribe https://github.com/notifications/unsubscribe-auth/AF4DAIRMCFTBNK5H7H3FUIDUSBOKRANCNFSM4FBLK2TQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

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[hellresistor]

In case anyone's interested, they seem to have changed the design on the S26 to make the pads much more accessible.

Thank you. I add this info. If you want connect without solder. just use a dupont female with clamps like this https://pt.aliexpress.com/item/4001009999023.html?gatewayAdapt=glo2bra

[domhardt]

In case anyone's interested, they seem to have changed the design on the S26 to make the pads much more accessible.

I can confirm this new S26 design. Two S26 for Germany were delivered to me yesterday (2022-11-24) and looked exactly like that. The silkscreen on the PCB reads "Sonoff S26 v2.6". Both work without issues using the TASMOTA Sonoff S2X configuration.

[Zuikkis]

What's interesting and should be noted, the new design no longer uses isolated transformer. 3.3V is regulated directly from mains voltage. Electrically aware person can confirm this from above pictures. D81 rectifier is directly in mains, then U2 drops the voltage to lower (5V I think) and then it's regulated to 3.3V by U1.

What this means, never plug it in while you have RX/TX etc going to your computer...

Also it's questionable whether it's safe to connect external sensors etc. At least you must be sure no metal parts can be touched, because they could be live.