ESP8266 Community Forum

It's interesting, because there is a LOT of space on the board. The main selling poing of the ESP8285 it it's reduced footprint (not needing a separate footprint). I think the combo of ESP8266 + flash is only marginally more expensive than a ESP8285. But apparently in such number every 1/10th of a cent counts.

On topic: I think they order them preprogrammed by Espressif. I am pretty sure Espressif has a facility where they can program the (flash) chip when it hasn't even been packaged yet (bare die), which is probably easier than doing it while packaged. The die must be tested before packaging anyway. Also, when they have access to the die, they can probably use other means of programming, directly to the flash chip instead of using the processor, either using SPI or even another way.

This board is part of a US-style wall switch, it has 3 touch-sensitive switches of some sort on the other side of the board. These switches are white, about 1 or 1.5 mm thick, about 1/2 inch by 1 inch in size. I'm guessing they're capacitive touch switches because they have to sense someone touching them through the cover plate. So the board has to be large enough to accomodate these switches.

I'm guessing that the ESP chips have a large contact pad on their under-side for direct soldering to the board which means there is no possibility for there to be traces running under the chip from any of the pins - yes?

I'll include another photo here - a close up of the ESP.

I am not sure. But I think it would rather be a challenge to solder to any of the unused pins. Good luck

I have made a WIFI connection from my PC to these switches when they are in AP mode - they do appear with SSID ITEAD-1000nnnn and the password 12345678 does work. So They must be sonoff clones then?

In which case, unless I really want to mess around with doing fine soldering work, then this looks like the best (or only) option:

https://youtu.be/ONFhXM5R-t4

Yes?