IPS,
These are also older buildings (about 50 years old). Four 4-unit buildings were built by a young man with a small inheritance. He sold one to pay off debts, then he and his wife raised 10 children on the income (plus his income from other work). He's nearing 90 so they have sold the enterprise to the children's LLC with a son-in-law taking on active management (with one of his son's living onsite). He is modernizing and making improvements (and raising rents). They are adding conduits between buildings which will help, installing security cameras in hallways, parking areas, etc. and they are replacing the 4-gang mailboxes in the lobbies. I believe there will be access to the basement from the mailboxes so adding wiring should not be a problem but I do not yet know how skilled he or his son are with things like this or whether he will want to install a custom system designed and maintained by a 74 year old tenant with major health issues (and who can no longer get out to hardware stores to see what's available). I'm proposing a WiFi camera with two way audio mounted in a recess next to the mailboxes that will allow up to eight P2P connections at the same time. The cameras I'm considering have Android, iOS, Windows, etc. apps for viewing the camera and communicating via the audio link. Also, I've no clue as to the speed of sending a message to a remote phone via the Internet - unless it's immediate it doesn't seem practical for this application. With one hand paralyzed, I have no smartphone with which to experiment although I may get a $65 Fire tablet or a prepaid Tracphone to experiment. I have no need for messages, email or audio since I'm rarely out. But, when I hear the doorbell, I'd like to be able to view the camera before going to the door.
However, Tuicemen and others here can probably pick this up and run with it. There's a free version of ZBasic for the ESP8266 and Tuicemen is already experimenting with the ESP8266 in another application plus he's far more experienced with IP cameras than am I. The
WeMos D1 mini has a scripting language (LUA) preloaded and has
12 11 interrupt driven digital inputs so it should, in principle, be a rather simple and straightforward application - sense the pushing of a doorbell (need extra contacts on the pushbuttons) and send a message to the appropriate tenants phone (or PC, in my case). I haven't looked but there's likely to be someone (or multiple someones) who has (have) documented similar uses of the ESP8266 online. There is also an Arduino variant for the ESP8266 as well as a GCC compiler.
Both the camera I'm considering and the WeMos modules will come by slow boat from China so it's likely to be 4-6 weeks before I can have hardware to play with. Plus, I'll likely be busy with a brain transplant in the meantime.
https://www.laser.com/dhouston/cm15a2z.htmlEDIT: As I expected there are numerous online documentations of similar applications. Here's one that's close to what we need.
http://www.eevblog.com/forum/projects/send-text-message-using-esp8266-when-home-alarm-goes-off/There's another Arduino/ESP8266 related application for sending email.
http://forum.arduino.cc/index.php?topic=286905.15And there are many other, similar applications.
https://www.bing.com/search?q=esp8266+send+message+to+smartphone&pc=MOZI&first=15&FORM=PORE