ESP8266 Community Forum

- Fri Oct 02, 2020 3:46 am #88980 It is certainly true that an OTA can fail so one should have a fall back plan. The incidence of OTA failure can be very low if one is careful particular if it is well tested first and also one can often build in a special start up (with say a push button depressed) that then skips all non-essential activity other than wifi and OTA. With these I have only screwed up OTA twice over a large number of updates over the years.

As it can be inconvenient to physically remove the ESP module itself for fall-back I normally build in header pin access to TX, RX, GPIO00, and GND. I can then use USB serial module with flying leads to effect a recovery.

- Fri Oct 02, 2020 3:56 am #88983 Yes, like I said, a sort of ICSP connector.

Using RBOOT, one can make an almost failsafe OTA mechanism, where the new slot is booted only once and only when it has completely finished booted, it may be activated permanently. This mechanism will only fail if something is crashing immediately after the step where the permantent activation happens. It does happen in practice, but it's very rare.

But for myself I rely on the 2 mm pin headers and sockets, so the ESP can be either re-flashed or even replaced when broken (which also is rare, but also I already experienced it).

Another option might be is to create a PCB that interfaces from 2 mm to 2.54 mm in your own layout. I did this once, a PCB that can "interface" between any of ESP01, ESP07, ESP12 and ESP201 (and either socket or device can be one of them).

- Tue Oct 06, 2020 8:31 am #89034 Thx for the late reply and thx for all the suggestions!

A few comments:
All these breakout boards: That's not what I'm looking for, as the ESP is soldered to that. I want to have it easily removeable on the minimal space.

The esp201 is an interesting thing, because it at least has 2.54mm pitch pin headers, instead of 2. So I could at least mount it to a PCB...

OTA: Yes, I need to do that one day, but all the comments about still being able to have it easily removeable in case of a failure stand

I'm now going with simple 2mm Dupont connectors: Luckily the 2mm pin headers I stick to the ESP-12F are so tight, I don't have to solder them. So I can easily remove them again and instead of soldering cables to these 2mm pin headers (which is absolutely *horrible*), I simply connect them with these Dupont connectors.

* 2P/3P/4P: https://www.aliexpress.com/item/32494185149.html
* 5P/6P/7P: https://www.aliexpress.com/item/32496148205.html
* 8P: https://www.aliexpress.com/item/32493962949.html
Wasn't easy to actually find 2mm pitch Dupont headers, was the only seller I found that sells them...

With this, I can have the ESP "flying around" in the cases, next to the PCB with the battery socket, some resistors, transistors, capacitors and what else I need for a project. And I can easily remove it by removing the Dupont connectors and then removing the pin headers and stick the ESP onto my devboard I have linked in my original post.

Hope this will help other strange people like me
Thanks again for all the input!