We’ve used the ESP8266 WiFi chip on all our recent products, such as OSBee, OpenGarage. I honestly think it’s more reliable compared to the Ethernet chip. WiFi is the future, and I don’t think security is any problem, since ESP8266 supports all modern WiFi security standard. In the rare cases of weak WiFi signal, you can add a WiFi range extender to boost the WiFi signal (and ESP8266 has a version with external antenna to boost the reception considerably).
If you look around, almost all modern gadgets and Internet of Things are WiFi only — Nest, Amazon Echo, wireless power sockets, garage door openers, your mobile phones, your laptops… Very few devices still provide Ethernet jack. Those who don’t trust WiFi for reliability: I am kind of surprised: you use WiFi-only gadgets on a day to day basis, like your mobile phone, your laptop. How do you avoid using WiFi at all? I really think a lot of concerns about WiFi are overstated. As a computer science researcher, I trust WiFi myself.
On the product webpage, we did specify that if you absolutely still want the older version 2.3, we can still ship them, it’s just that there is generally 2-3 week lead time since we don’t regularly stock these any more. Also, if the issue is mainly to bring WiFi to a place where WiFi doesn’t exist, we have a one-page document explaining how to use a portable WiFi access point (which costs just about $15 to $25) to serve as an interface between Ethernet and WiFi:
http://rayshobby.net/docs/os30_wired_howto.pdf
this is similar to using a WiFi adapter to enable WiFi access for OS 2.3 (as you know, OS 2.3 has only wired Ethernet and no WiFi), except it’s done the reverse way.
Going back to the earlier questions:
– pin out and schematic of Expander 3.0 are now uploaded to Github: https://github.com/OpenSprinkler/OpenSprinkler-Hardware
– new firmware updates will NOT leave version 2.3 behind: new firmware features will always be available to both 3.0 and 2.3 (except hardware differences like sensor 2 which doesn’t exist on 2.3). We will probably not be able to continue supporting new firmware features for 2.0, 2.1 and 2.2 (not because we don’t want to, but because they have smaller microcontroller that cannot fit the large firmware any more), but 2.3 will definitely still be supported.
– the microUSB on OpenSprinkler 3.0 is for serial communication only, it’s not a USB host. This is the same on version 2.3.