The final version of the boards contains few notable improvements
- Removed the PCB under the ESP8266 antenna. The previous design had PCB + Ground Plane, which resulted in VERY low reception. It worked just few meters away from the router.
- Removed the Temperature Probe - On the one hand - it does not really measure real temperature, on the other hand it populates the Single Analog port, and makes it unavailable for other usages
- Added place for an optional LDR (in case the Analog port is not used - one could add an LDR for added value)
- The connection between GPIO 16 and RST (Deep Sleep) is not bridged via a 0603 0ohm resistor (jumper). Depending on application it may be enabled or not
- Added a Power 5V line. That is - controlled via a SOT232 mosfet and one GPIO. This way you can connect power hungry modules and then turn them on or off. There are small mosfets rated ~ 2-3 amps for couple of cents.
- The big 12mhz crystal for the CH340G was replaced by a small patch ceramic oscillator to save space
- Added an additional mounting hole
- Added additional test pads for the unused GPIOs
- Added one Diode in series with the power to the WS2812B LED. It turned out, when powered directly via a USB Battery bank, the voltage can be 5.30-5.40v. And apparently WS2812B, does not light if VIN is > 5.15V. So putting a generic small Diode would drop 0.3-0.4V
Here is how the latest design looks like