Just a quick note here to draw your attention to Tracker-J’s v2 ESP8266 mains controller board.
This board has a nice little break-out for ESP-07 or ESP-12 modules on the L/H side and a standard MOC3041 zero-crossing, isolated triac driver on the right. The ESP8266 side has a voltage regulator, pull-ups and a programming jumper. The triac side is pretty much the standard circuit (including component locations for a snubber network) that we’ve all come to know and love over the years. The bulk of the components are through-hole, with a smattering of SMD on the rear of the ESP8266 module side (but only two SMD resistors on the back of the MOC side).
The designer, Tracker-J, has a couple of photo’s of the board split down the middle to make discrete ESP8266 module and mains power control boards, but there are no holes or slots at the cut point, so you’ll have to get out your hacksaw or guillotine to get the two halves apart. To be honest though, the attraction of the board is its functionality as a simple, generic, wireless mains switch, so I don’t envisage too many people reaching for a hacksaw. Having said that, the boards are available in batches of 10 from Dirty PCBs, so it might be nice to have a snappable version to allow re-purposing of any excess units.
My “wish list” for v3 would be the addition of slots/holes to make the two halves snappable, mounting holes (three would do), the repositioning of R6 from the cathode lead of the MOC to the ESP8266 side of the “CMD” jumper on the anode side and the addition of a silk-screened skull-and-crossbones “DANGER!” label on the mains control side. Before putting it up on Tindie “to make a (small) fortune”, Pete Scargill suggests that it would also benefit from a barrel or micro-USB connector to enable the use of a cheap phone charger as a low voltage PSU.
All in all though, version 2 is still one of the better ESP8266 boards out there. Check Tracker-J’s site for his other, ESP8266-related projects, including adding a DS3231 I2C RTC board and a perfboard breakout for the ESP07/ESP12 modules.