ESP8266 OTA Serial Monitor DIY Kit

ESP8266 self hosted WIFI-to-UART bridge

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andrey-malyshenko has 717 orders / 23reviews
Ships from Poland
Does it ever happened to you that one of your Raspberry Pis falls into boot loop somewhere on the top shelf? Every Pi running from sdcard is doomed to refuse to work one day (unless you run them from read-only filesystem, which you should do BTW).
When that happens I usually disconnect it and bring to the bench to check serial console. Recently It took me more time to actually disassemble device from it's place, than actually fixing it. That get me thinking, surely some people made ESP8266 serial bridge over-the-air, and surely I'd like to have one nearby, next time ping is not coming back.
Not long after first prototype was born, fast forward few month I have revision A board on my bench. Short feature list
- ESP82266 with WifiManager
- One Serial connected to the host, another accessible via header for debugging purposes
- RGB led for status indication (If connected to Wifi and if connected to client)
- On-Board Li-Ion battery and battary management circuit

Here how it works in a nutshell

And below is a pinout for my specific implementation

  • Demo

    andriy.malyshenko01/31/2023 at 13:10 0 comments

  • Demo

    andriy.malyshenko01/31/2023 at 13:08 0 comments

  • Revision B is coming

    andriy.malyshenko12/17/2022 at 22:44 0 comments

    After using terminal monitor for a while I've decided to review feature list, or more specifically get rid of the stuff I don't use. And add screen instead.

    It is not a big screen, only 8x21 symbols with tiny font, however now tool can be used completely offline. At least to see serial output from target device, you don't need web app.

    This is how it looks like in practice

    Side effect of those changes - I were able to make the board DIY kit like. This way I hope to lower the price at least twice!

View all 3 project logs

  • 1
    Start by checking all parts are present

    Make sure that all parts came in good shape and no apparent damage is done on the way. Flash Terminal software to Wemos D1 board just to make sure it works.

  • 2
    Solder Wemos D1 module - headers to module first

    Solder headers to the Wemos D1 module. Long part of the header should be directed to the motherboard. Make sure to align them right, use motherboard as an aligning tool. When soldered it will be tightly pressed against battery socket.

    Start with just one pin each side and double check your work. Then you can proceed to other pins.

  • 3
    Solder Wemos D1 module - motherboard side

    Solder headers to the motherboard from the back side.

View all 10 instructions

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Vincèn wrote 07/11/2022 at 12:10 point


Is it possible to use that device to control by RS-232 some devices ? Does it output some standard RS-232 levels ? I would use it with ESPHome and Home Assistant to control some devices through UART ;)



  Are you sure? yes | no

andriy.malyshenko wrote 01/31/2023 at 10:16 point

Hi Vincèn

AFAIK it depends. It will definitely wont handle +/-15V voltage levels, You'd need voltage conversion first. Please check what is actual voltage levels that you have. In many cases (read modern devices), level is 3.3V or 5V. In that case it should work.

  Are you sure? yes | no

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