This project use only low costs components. So you are able to create it with:
3$ Arduino nano or mini/pro
3$ FSK-decoder (1$ if you get a SMD decoder)
3$ ESP8266 WiFi module
3$ 16x2 display, maybe a 20x4 would be better but more expensive
That's all! All circuits/schemas are described in this page and source code is available too!
Difficulty in this project?
The idea is simple: block every call center. But it is not easy, because they change number each day. Create a database is a solution, get the phone number from search.ch the best way :D So, what are the problems in this project?
Connect the caller ID chip to Arduinoworks!
Write the entire code with only 2kb of RAM!
Connect WiFi module
Get a fast answer from server with the phone number
Create first prototypes
Get API (key) from search.chgot up to 1000 requests/day!
Maybe this project will fail... Maybe at point 1 :P I hope I can do it up to the last point!
Current progress for a working prototype:
*Currently, both my ESP8266 are broken... They doesn't work anymore :( I am waiting for other ESP's...